ATL: LEE - Advisories

[WalterWhite]

Tropical Depression Thirteen Advisory Number 1
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Tue Sep 05 2023

...NEW TROPICAL DEPRESSION FORMS IN THE CENTRAL TROPICAL ATLANTIC...
...FORECAST TO BECOME A POWERFUL HURRICANE BY THE END OF THE WEEK...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.5N 40.2W
ABOUT 1425 MI...2295 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


WATCHES AND WARNINGS
--------------------
None.

Interests in the Leeward Islands should monitor the progress of
this system.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the center of Tropical Depression
Thirteen was located near latitude 12.5 North, longitude 40.2 West.
The depression is moving toward the west-northwest near 15 mph (24
km/h), and this motion is expected to continue for the next few
days.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
The depression is forecast to be a hurricane in a couple of days
and could become a major hurricane in a few days.

The estimated minimum central pressure is 1008 mb (29.77 inches).


HAZARDS AFFECTING LAND
----------------------
None.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.


Tropical Depression Thirteen Discussion Number 1
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Tue Sep 05 2023

Satellite images indicate that the tropical wave (Invest AL95) that
we have been following for several days has become better organized
this morning, with many curved low-level banding features. A
partial scatterometer pass near 1201 UTC indicated a well-defined
center had formed, with winds speeds of about 30 kt. Thus,
advisories have been initiated on Tropical Depression Thirteen, and
the current intensity is set to 30 kt.

The depression is moving west-northwestward at about 13 kt. A
mid-level ridge over the central Atlantic is expected to persist to
the north of the tropical cyclone, keeping the system moving with
this general motion through Saturday. The spread in the model
guidance is remarkably low for a first advisory, and the official
forecast is near or west of the model consensus. However, it
should be noted that the NOAA corrected-consensus aids and some
ensemble members are still to the left of the official forecast, so
it is too early to determine exactly how close this system will get
to the Leeward Islands given the average track forecast error at
those time ranges.

The environment around the depression appears to be conducive for
strengthening. The only obvious hindering factor is
light-to-moderate northeasterly shear, which should keep the
intensification rate in check in the short term. However, in two to
three days, this shear is forecast to relax with an upper-level
ridge building near the cyclone, and the system should be moving
over record-warm waters of near 30 deg C east of the Lesser Antilles
(that would look more in place in the Gulf of Mexico). These
factors could support rapid intensification by the end of the week,
although it too early to determine exactly when this might occur
until a better-defined inner core forms. The NHC intensity forecast
is extremely bullish for a first forecast, but remarkably lies
below the intensity consensus. All indications are that the
depression will become a strong hurricane by the end of the forecast
period.

KEY MESSAGES:

1. The depression is forecast to become a major hurricane by
this weekend and could bring impacts to the Leeward Islands by that
time. While it is too soon to determine the location and magnitude
of these possible impacts, interests in this area should monitor
the progress of the depression and updates to the forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 12.5N 40.2W 30 KT 35 MPH
12H 06/0000Z 12.8N 42.1W 40 KT 45 MPH
24H 06/1200Z 13.6N 44.7W 50 KT 60 MPH
36H 07/0000Z 14.4N 47.2W 60 KT 70 MPH
48H 07/1200Z 15.3N 49.7W 70 KT 80 MPH
60H 08/0000Z 16.2N 52.2W 80 KT 90 MPH
72H 08/1200Z 17.3N 54.7W 95 KT 110 MPH
96H 09/1200Z 19.4N 59.1W 115 KT 130 MPH
120H 10/1200Z 21.5N 63.5W 120 KT 140 MPH

$$
Forecaster Blake

[cycloneye]

Tropical Storm Lee Advisory Number 2
NWS National Hurricane Center Miami FL AL132023
500 PM AST Tue Sep 05 2023

...TROPICAL STORM LEE EXPECTED TO RAPIDLY INTENSIFY INTO AN
EXTREMELY DANGEROUS HURRICANE BY THE WEEKEND...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 41.8W
ABOUT 1315 MI...2115 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
None.

Interests in the Leeward Islands should monitor the progress of
this system.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Tropical Storm Lee was
located near latitude 13.2 North, longitude 41.8 West. Lee is moving
toward the west-northwest near 16 mph (26 km/h), and this motion is
expected to continue for the next few days with a slight reduction
in forward speed.

Maximum sustained winds have increased to near 45 mph (75 km/h)
with higher gusts. Lee is forecast to be a hurricane within a couple
of days and will likely become a major hurricane by Friday.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
None.


Tropical Storm Lee Discussion Number 2
NWS National Hurricane Center Miami FL AL132023
500 PM AST Tue Sep 05 2023

1-min GOES-16 satellite imagery shows that the tropical cyclone has
been improving in structure throughout the day, with additional
curved banding features and a new burst of convection near the
center. A late-arriving ASCAT-C pass indicated maximum winds
supporting 35 kt, and the satellite presentation has notably
improved since that time. The initial wind speed is set to 40 kt
to match the satellite trends.

Lee is moving west-northwestward at about 14 kt. There are no
significant changes to the NHC track forecast with a mid-level ridge
over the central Atlantic likely to persist to the north of the
storm. This ridge should provide a steady steering current, with a
general west-northwestward course expected through the weekend with
some reduction in forward speed. The spread in the model guidance
remains low, and the official forecast is adjusted a bit to the
northeast closer to the model consensus. Still, it is too early to
determine exactly how close this system will be to the Leeward
Islands given the average track forecast error at those time ranges.

It is becoming a question of when and not if rapid intensification
(RI) occurs with Lee. A well-defined outflow pattern has developed
over the circulation, and there are some hints on a recent SSMI/S
microwave pass that parts of an inner core are forming. There's
still some notable northeasterly shear that could keep Lee in
check for the next day or two, so the NHC intensity forecast will
stay at a more moderate rate of intensification during that time.
All of the models decrease the shear by Friday, so RI is explicitly
forecast at that time frame while Lee is moving over extremely warm
waters. The new forecast is adjusted higher than the last advisory,
near the model consensus, but there's a notable contingent of
guidance higher than this forecast. There is increasing confidence
on Lee becoming a very powerful hurricane by this weekend.

KEY MESSAGES:

1. Lee is forecast to become a major hurricane by this weekend and
could bring impacts to the Leeward Islands by that time. While it
is too soon to determine the location and magnitude of these
possible impacts, interests in this area should monitor the
progress of Lee and further updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 13.2N 41.8W 40 KT 45 MPH
12H 06/0600Z 13.7N 43.7W 50 KT 60 MPH
24H 06/1800Z 14.4N 46.2W 60 KT 70 MPH
36H 07/0600Z 15.2N 48.5W 70 KT 80 MPH
48H 07/1800Z 16.2N 51.0W 80 KT 90 MPH
60H 08/0600Z 17.2N 53.6W 90 KT 105 MPH
72H 08/1800Z 18.3N 56.0W 110 KT 125 MPH
96H 09/1800Z 20.4N 60.5W 120 KT 140 MPH
120H 10/1800Z 22.2N 64.3W 125 KT 145 MPH

$$
Forecaster Blake

[cycloneye]

BULLETIN
Tropical Storm Lee Advisory Number 3
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Tue Sep 05 2023

...LEE EXPECTED TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS
HURRICANE BY THE WEEKEND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.5N 43.0W
ABOUT 1230 MI...1980 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the Leeward Islands should monitor the progress of
this system.


Tropical Storm Lee Discussion Number 3
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Tue Sep 05 2023

The satellite structure of Lee has continued to improve tonight. A
prominent curved band of deep convection wraps around the western
and southern portions of the circulation. Recent SSMIS and GMI
microwave images reveal deep convection is occurring near the
center, though it is slightly displaced by some northeasterly shear.
There are also hints of a formative inner core trying to take shape,
all of which suggest that Lee is strengthening. The initial
intensity is raised to 45 kt for this advisory, in best agreement
with a T3.0 Dvorak classification from TAFB.

Lee continues to move west-northwestward at about 15 kt. A mid-level
ridge over the central subtropical Atlantic is expected to be the
primary steering mechanism for the next several days, with Lee
forecast to continue on a west-northwestward heading across the
central tropical Atlantic through the forecast period. Once again,
the track guidance is in fairly good agreement on this scenario.
Overall, the latest NHC track forecast is very similar to the
previous prediction, with only minor adjustments that keep our
forecast between the simple and corrected consensus aids. Users are
reminded that the average NHC forecast track errors are around 125
and 175 n mi on days 4 and 5, respectively. Thus, it is too soon to
determine exactly how close this system will be to the Leeward
Islands by the weekend.

The atmospheric and oceanic conditions appear extremely favorable
for rapid intensification (RI) during the next several days,
particularly once the northeasterly shear over Lee subsides in a day
or so. The forecast track of Lee brings the cyclone over anomalously
warm SSTs during the next several days, with generally low shear and
favorable upper diffluence to support significant strengthening. The
updated NHC intensity forecast has been adjusted slightly higher
than the previous one, toward the latest IVCN and HCCA aids. This
forecast calls for Lee to become a hurricane in 24 h and a major
hurricane by 60 h, with continued intensification thereafter. It is
noted that the regional hurricane models depict even stronger
solutions, so future adjustments could be necessary. Regardless,
Lee bears close monitoring as there is high confidence it will
become a very powerful hurricane by this weekend.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane by late this week and
could bring impacts to the Leeward Islands this weekend. While it is
too soon to determine the location and magnitude of these possible
impacts, interests in this area should monitor the progress of Lee
and further updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 13.5N 43.0W 45 KT 50 MPH
12H 06/1200Z 14.1N 44.9W 55 KT 65 MPH
24H 07/0000Z 14.9N 47.2W 65 KT 75 MPH
36H 07/1200Z 15.7N 49.7W 75 KT 85 MPH
48H 08/0000Z 16.6N 52.2W 90 KT 105 MPH
60H 08/1200Z 17.8N 54.8W 105 KT 120 MPH
72H 09/0000Z 18.9N 57.1W 115 KT 130 MPH
96H 10/0000Z 20.8N 61.5W 125 KT 145 MPH
120H 11/0000Z 22.5N 65.0W 130 KT 150 MPH

$$
Forecaster Reinhart

[cycloneye]

BULLETIN
Tropical Storm Lee Advisory Number 4
NWS National Hurricane Center Miami FL AL132023
500 AM AST Wed Sep 06 2023

...LEE APPROACHING HURRICANE STRENGTH...
...EXPECTED TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS
HURRICANE BY THE WEEKEND...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.7N 44.6W
ABOUT 1265 MI...2040 KM ESE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES



Tropical Storm Lee Discussion Number 4
NWS National Hurricane Center Miami FL AL132023
500 AM AST Wed Sep 06 2023

Lee continues to strengthen at a quick pace. Satellite images show
that deep convection has been increasing in intensity and coverage
in a central dense overcast feature and in a sprawling curved band
over the western semicircle. The Dvorak classifications from TAFB
and SAB are now 3.5/55 kt, and accordingly, the initial intensity
has been increased to 55 kt. Lee is not far from hurricane
strength, and it likely will achieve that status later today.

The tropical storm is moving west-northwestward at 14 kt on the
south side of a subtropical ridge over the central Atlantic. This
ridge is expected to persist to the north of Lee during the next
several days, keeping the storm on a west-northwest track through
the remainder of the week and over the weekend. Although the NHC
forecast and the model guidance continue to show Lee passing to the
north of the northern Leeward Islands this weekend, users are
reminded that the details of the track forecast are still uncertain
at those time ranges. For reference, the average NHC forecast track
errors are around 125 and 175 n mi on days 4 and 5, respectively.
The NHC track forecast lies on the southern side of the model
guidance envelope, roughly halfway between the usually most skillful
consensus aids, HCCA and TVCA.

Lee has already been strengthening fairly quickly despite some
east-northeasterly vertical wind shear over the system. Since the
shear is expected to relax while the storm remains over very warm
water and in a moist environment, continued steady to rapid
intensification is expected during the next few days. Most of the
intensity models are very aggressive, bringing Lee to major
hurricane status by the weekend, but they don't show much change in
strength in the short term. In addition, even the global models
like the GFS and ECMWF show explosive intensification and forecast
Lee's minimum pressure to drop by more than 60 mb by the end of the
forecast period. The NHC intensity forecast lies near the high end
of the model guidance during the next 24-48 hours, but falls to near
the middle of the guidance envelope after that. Regardless of the
details, there is high confidence that Lee will be a powerful
hurricane late this week and over the weekend.

KEY MESSAGES:

1. Lee is forecast to become a major hurricane by late this week and
could bring impacts to the Leeward Islands this weekend. While it is
too soon to determine the location and magnitude of these possible
impacts, interests in this area should monitor the progress of Lee
and further updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 13.7N 44.6W 55 KT 65 MPH
12H 06/1800Z 14.3N 46.4W 70 KT 80 MPH
24H 07/0600Z 15.1N 48.8W 80 KT 90 MPH
36H 07/1800Z 16.0N 51.3W 90 KT 105 MPH
48H 08/0600Z 17.0N 53.7W 105 KT 120 MPH
60H 08/1800Z 18.1N 56.2W 120 KT 140 MPH
72H 09/0600Z 19.2N 58.4W 130 KT 150 MPH
96H 10/0600Z 21.1N 62.4W 130 KT 150 MPH
120H 11/0600Z 22.7N 65.5W 130 KT 150 MPH

$$
Forecaster Cangialosi

[Iceresistance]

BULLETIN
Tropical Storm Lee Advisory Number 5
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Wed Sep 06 2023

...LEE CLOSE TO HURRICANE STRENGTH...
...LIKELY TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR HURRICANE BY SATURDAY...

SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
Tropical Storm Lee Discussion Number 5
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Wed Sep 06 2023

Recent geostationary and microwave satellite imagery shows that the
convective structure of Lee continues to improve. Visible imagery
shows a well-defined curved band of convection that wraps around
the eastern portion of the circulation, and a couple of earlier
microwave images revealed a ragged mid-level eye that was open to
the north. The low-level structure noted in the 1156 UTC GMI
microwave overpass was quite organized with a well-defined
low-level eye feature. The latest subjective Dvorak T-numbers from
SAB and TAFB were T3.5 (55 kt), but given the continued increase in
structure the initial intensity has been raised to 60 kt.

Lee is moving west-northwestward at about 12 kt to the south side
of a low- to mid-level ridge over the central Atlantic. The ridge
is forecast to remain intact for the next several days and a
west-northwestward motion at around the same forward speed is
expected through the weekend. The track guidance continues to
show that the core of Lee will pass to the north of the
northern Leeward Islands, however interests in those islands
should continue to monitor the latest forecasts as the typical
three- and four-day NHC track errors are about 90 and 125 n mi,
respectively. The NHC track forecast is again along the southern
side of the guidance envelope, between the faster and farther south
HFIP corrected consensus model, and the TVCA multi-model consensus
aid.

Despite the continued increase in organization there appears to be
some east-northeasterly shear over Lee. The shear is forecast to
relax within the next 24 hours, and given the well-organized
low-level structure of the cyclone, steady to rapid strengthening
appears likely as Lee traverses SSTs of 29-30C during the next few
days. The NHC intensity forecast is similar to the previous
advisory, bringing Lee to hurricane strength very soon, and to a
major hurricane within 48 hours. Continued strengthen seems likely
after that time, but hard-to-predict eyewall replacement cycles
could cause some fluctuations in intensity later in the weekend and
early next week. The NHC intensity forecast is near the upper-end
of the guidance and calls for Lee to reach category 4 intensity in
two to three days.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane by early Saturday and
could bring impacts to the northern Leeward Islands this weekend.
While it is too soon to determine the location and magnitude of
these possible impacts, interests in this area should monitor the
progress of Lee and further updates to the forecast.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday. These swells are likely to cause
life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 06/1500Z 14.1N 45.5W 60 KT 70 MPH
12H 07/0000Z 14.8N 47.3W 75 KT 85 MPH
24H 07/1200Z 15.7N 49.6W 85 KT 100 MPH
36H 08/0000Z 16.6N 52.2W 95 KT 110 MPH
48H 08/1200Z 17.6N 54.7W 105 KT 120 MPH
60H 09/0000Z 18.7N 56.9W 120 KT 140 MPH
72H 09/1200Z 19.8N 59.2W 130 KT 150 MPH
96H 10/1200Z 21.5N 62.8W 130 KT 150 MPH
120H 11/1200Z 22.9N 65.7W 130 KT 150 MPH

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 6
NWS National Hurricane Center Miami FL AL132023
500 PM AST Wed Sep 06 2023

...LEE STRENGTHENS INTO A HURRICANE...
...LIKELY TO INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR HURRICANE
BY EARLY SATURDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...14.9N 46.4W
ABOUT 1130 MI...1815 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the northern Leeward Islands should monitor the
progress of this system.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Hurricane Lee was located
near latitude 14.9 North, longitude 46.4 West. Lee is moving toward
the west-northwest near 14 mph (22 km/h), and this motion is
expected to continue for the next few days with a slight reduction
in forward speed over the weekend.

Maximum sustained winds have increased to near 75 mph (120 km/h)
with higher gusts. Continued steady to rapid strengthening is
forecast, and Lee is expected to become a major hurricane in a day
or two.

Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 90 miles
(150 km).

The estimated minimum central pressure is 991 mb (29.27 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Lee can be found in the Tropical Cyclone Discussion
under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC and on the
web at hurricanes.gov/text/MIATCDAT3.shtml

SURF: Swells generated by Lee are expected to reach portions of
the Lesser Antilles on Friday, and reach the British and U.S.
Virgin Islands and Puerto Rico this weekend. These swells are
likely to cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

$$
Forecaster Brown




Hurricane Lee Discussion Number 6
NWS National Hurricane Center Miami FL AL132023
500 PM AST Wed Sep 06 2023

Lee has continued to quickly organize today. Convective banding,
especially over the eastern semicircle of the storm, has increased
since this morning. The center is embedded within a small central
dense overcast, and earlier this afternoon there was a hint of a
ragged eye in visible imagery. Although subjective Dvorak
intensity estimates from SAB and TAFB were still T3.5 (55 kt) and
most of the objective estimate are slightly below hurricane
strength, the initial intensity has been increased to 65 kt based
on the continued improvement in organization this afternoon, and
the presence of a mid-level eye in a recent SSMIS microwave
overpass. Lee becomes the fourth hurricane of the 2023 Atlantic
hurricane season.

Recent satellite fixes suggest that Lee took a northwestward jog
this afternoon, however the longer-term motion is still
west-northwestward at about 12 kt. A mid-level ridge located
to the north of Lee should continue to steer the cyclone on a
west-northwestward heading through the weekend. Near the end of
the forecast period, Lee will be approaching the western periphery
of the ridge and the forward motion of the cyclone is likely to
slow at that time. The dynamical model guidance continues to
indicate that the core of Lee will pass to the north of the
northern Leeward Islands, however interests in those islands
should continue to monitor the latest forecasts as the typical
three-day NHC track error is about 90 n mi. The NHC track
forecast is again along the southern side of the guidance
envelope, between the faster and farther south HFIP corrected
consensus model, and the TVCA multi-model consensus aid. The
updated track foreast is slightly north of the previous advisory
primarily due to the more northward initial position, and it is a
little slower than the previous forecast to be closer to the
latest consensus aids.

The light to moderate east-northeasterly shear over Lee is forecast
to decrease overnight, and that along with warm SSTs and a moist
atmosphere along the forecast track should allow for additional
intensification. With the small inner core seen in microwave
imagery and favorable environmental conditions, a period of rapid
strengthening is a distinct possibility within the next day or two.
Although the exact timing of any rapid strengthening is tricky to
anticipate, the official forecast calls for a substantial 65-kt
increase in strength during the next 72 hours. This is similar to
the previous forecast, and is near the upper end of the intensity
guidance. By later in the weekend, hard-to-predict eyewall
replacement cycles could cause some fluctuations in intensity.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane by early Saturday and
could bring impacts to the northern Leeward Islands this weekend.
While it is too soon to determine the location and magnitude of
these possible impacts, interests in this area should monitor the
progress of Lee and further updates to the forecast.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday, and the British and U.S. Virgin Islands
and Puerto Rico this weekend. These swells are likely to cause
life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 06/2100Z 14.9N 46.4W 65 KT 75 MPH
12H 07/0600Z 15.6N 48.2W 75 KT 85 MPH
24H 07/1800Z 16.5N 50.6W 85 KT 100 MPH
36H 08/0600Z 17.5N 53.0W 95 KT 110 MPH
48H 08/1800Z 18.6N 55.3W 110 KT 125 MPH
60H 09/0600Z 19.6N 57.5W 120 KT 140 MPH
72H 09/1800Z 20.4N 59.4W 130 KT 150 MPH
96H 10/1800Z 21.9N 62.9W 130 KT 150 MPH
120H 11/1800Z 23.0N 65.2W 125 KT 145 MPH

$$
Forecaster Brown

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 7
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Wed Sep 06 2023

...LEE FORECAST TO BECOME AN EXTREMELY DANGEROUS MAJOR HURRICANE BY
FRIDAY...
...LARGE OCEAN SWELLS LIKELY TO REACH THE LESSER ANTILLES, THE
VIRGIN ISLANDS, AND PUERTO RICO THROUGH THE WEEKEND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.4N 47.7W
ABOUT 1035 MI...1665 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...989 MB...29.21 INCHES

Hurricane Lee Discussion Number 7
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Wed Sep 06 2023

Lee has an asymmetric structure this evening, with the bulk of the
convective activity located to the east of the center. Dvorak
estimates from TAFB and SAB were a pair of T4.0s/65 kt, but
objective Dvorak estimates from UW-CIMSS are a little higher.
Therefore, Lee's initial intensity is set at 70 kt.

The initial motion remains west-northwestward, or 295/12 kt, with
Lee situated to the south of the subtropical ridge. Ridging is
expected to build westward, and even out ahead of the hurricane
over the southwestern Atlantic, during the next 5 days. As a
result, Lee is likely to maintain a west-northwestward trajectory
but gradually slow down beyond day 2, with its forward speed
decreasing to about 7 kt by day 5. The new NHC track forecast
is right on top of the previous prediction during the first
3 days of the forecast. After that, the official forecast has been
nudged westward, leaning toward the latest TVCX and HCCA consensus
aids. The track model envelope continues to indicate that the
core of Lee will pass to the north of the northern Leeward
Islands. However, interests in those islands should continue to
monitor Lee's forecasts as the typical three-day NHC track error is
about 90 n mi, and the northernmost Leeward Islands currently have
a 1-in-4 chance of experiencing sustained tropical-storm-force
winds on the southern side of the storm.

Global model fields show a well-defined upper-level anticyclone
developing over Lee during the next 24 hours and persisting over
the hurricane into the weekend, which should keep the deep-layer
shear quite low. In addition, oceanic heat content values will
double along Lee's track during the next 3 days. As a result,
rapid intensification (RI) is forecast to begin on Thursday, and
following the previous forecast, a 65-kt increase in strength is
predicted during the next 3 days, bringing Lee to high-end category
4 intensity. This forecast lies close to the HAFS dynamical model
and HCCA consensus aid solutions, and it is also supported by very
high RI probabilities from the DTOPS scheme for the 36-, 48-, and
72-hour forecast periods. Fluctuations in intensity are likely by
days 4 and 5 due to potential eyewall replacements, but Lee is
still expected to be a large and dangerous hurricane over the
southwestern Atlantic early next week.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane by early Friday,
with its core moving north of the northern Leeward Islands, the
Virgin Islands, and Puerto Rico this weekend into early next week.
There is the potential for tropical storm conditions to occur on
some of these islands over the weekend, and interests there should
monitor future updates to Lee's forecast.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday, and the British and U.S. Virgin Islands,
Puerto Rico, Hispaniola, the Bahamas, and Bermuda this weekend.
These swells are likely to cause life-threatening surf and rip
current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 07/0300Z 15.4N 47.7W 70 KT 80 MPH
12H 07/1200Z 16.1N 49.5W 75 KT 85 MPH
24H 08/0000Z 17.0N 51.9W 85 KT 100 MPH
36H 08/1200Z 18.1N 54.2W 105 KT 120 MPH
48H 09/0000Z 19.1N 56.5W 120 KT 140 MPH
60H 09/1200Z 20.1N 58.5W 130 KT 150 MPH
72H 10/0000Z 20.8N 60.3W 135 KT 155 MPH
96H 11/0000Z 22.0N 63.5W 130 KT 150 MPH
120H 12/0000Z 23.0N 66.1W 125 KT 145 MPH

$$
Forecaster Berg

[cycloneye]

Hurricane Lee Discussion Number 8
NWS National Hurricane Center Miami FL AL132023
500 AM AST Thu Sep 07 2023

Lee had been steady state overnight, but there are some signs that
intensification is beginning to resume. Satellite images show
evidence of an eye feature appearing within the central dense
overcast and fragmented bands that are now filling in around the
center. In addition, a better defined inner core seems to be
taking shape. The initial wind speed of 70 kt is at the high end
of the satellite estimates, but if these trends continue, the
intensity of the hurricane could increase quickly.

The initial motion remains west-northwestward, or 300/12 kt. The
hurricane has taken a slight jog to the north during the last few
hours. The steering pattern for Lee is straightforward. A
subtropical ridge situated to the north of the hurricane should
steer the system west-northwestward during the next several days,
but the forward speed will likely slow down late in the weekend and
early next week. The models have changed little this cycle, and
there is increasing confidence that the core of Lee will pass to the
north of the northern Leeward Islands. However, interests in those
islands should continue to monitor Lee's forecasts as the typical
three-day NHC track error is about 90 n mi, and the northernmost
Leeward Islands currently have a 1-in-4 chance of experiencing
sustained tropical-storm-force winds on the southern side of the
storm.

The environment around the cyclone looks ideal for rapid
intensification. The models are in fairly good agreement that
significant strengthening should begin later today and continue into
the weekend, when Lee will likely reach its peak intensity.
Fluctuations in strength are likely from days 3 to 5 due to
potential eyewall replacements, but Lee is still expected to be a
dangerous hurricane over the southwestern Atlantic early next week.
The NHC intensity forecast is at the high end of the guidance in the
short term given recent trends, but falls to near the middle of the
guidance envelope from 36 to 120 h.

As Lee slowly gains latitude and becomes significantly stronger,
its wind field is forecast to expand. This is expected to result
in a large area of high seas extending well away from the core of
the system.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane by early Friday, with
its core moving north of the northern Leeward Islands, the Virgin
Islands, and Puerto Rico this weekend into early next week. There is
the potential for tropical storm conditions to occur on some of
these islands over the weekend, and interests there should monitor
future updates to Lee's forecast.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday, and the British and U.S. Virgin Islands,
Puerto Rico, Hispaniola, the Bahamas, and Bermuda this weekend.
These swells are likely to cause life-threatening surf and rip
current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 07/0900Z 16.1N 48.6W 70 KT 80 MPH
12H 07/1800Z 16.8N 50.3W 85 KT 100 MPH
24H 08/0600Z 17.8N 52.7W 100 KT 115 MPH
36H 08/1800Z 18.8N 55.0W 115 KT 130 MPH
48H 09/0600Z 19.8N 57.1W 125 KT 145 MPH
60H 09/1800Z 20.6N 59.1W 135 KT 155 MPH
72H 10/0600Z 21.3N 60.7W 135 KT 155 MPH
96H 11/0600Z 22.5N 63.6W 125 KT 145 MPH
120H 12/0600Z 23.5N 65.9W 115 KT 130 MPH

$$
Forecaster Cangialosi

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 9
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Thu Sep 07 2023

...LEE RAPIDLY STRENGTHENING...
...LARGE SWELLS LIKELY TO REACH THE LESSER ANTILLES, THE VIRGIN
ISLANDS, AND PUERTO RICO THIS WEEKEND...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.4N 50.0W
ABOUT 870 MI...1405 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...983 MB...29.03 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the northern Leeward Islands should monitor the
progress of Lee.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the center of Hurricane Lee was located
near latitude 16.4 North, longitude 50.0 West. Lee is moving toward
the west-northwest near 15 mph (24 km/h), and this motion is
expected to continue through Friday. A slower motion toward the
west-northwest is forecast over the weekend. On the forecast track,
the core of Lee will move north of the northern Leeward islands
during the next few days.

Maximum sustained have quickly increased to near 105 mph (165 km/h)
with higher gusts. Rapid intensification is expected today and
tonight. Lee will likely become a major hurricane later today. Lee
is forecast to remain a very strong major hurricane through the
weekend

Hurricane-force winds extend outward up to 25 miles (35 km) from the
center and tropical-storm-force winds extend outward up to 90 miles
(150 km).




Hurricane Lee Discussion Number 9
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Thu Sep 07 2023

Lee is rapidly intensifying. Early this morning, a well-defined
low-to mid-level eye was observed in microwave imagery, a signal
that is often a precursor rapid intensification (RI). Since then,
Lee has developed an eye in visible and infrared imagery, with
subjective Dvorak Data-T estimates quickly increasing to as high as
5.5 during the past hour or so. Satellite classifications supported
an intensity of around 80 kt at 1200 UTC, but given the significant
improvement in Lee's appearance since then, the advisory intensity
is set at 90 kt.

The track guidance remains in very good agreement on the forecast
for Lee through the weekend and confidence in the track forecast is
high. Lee should continue west-northwestward, gradually slowing its
forward speed, moving along the southern periphery of a subtropical
ridge over the central Atlantic. Confidence continues to increase
that Lee will pass north of the northern Leeward Islands, though
swells associated with Lee will affect the islands starting
tomorrow. By the end of the forecast, the uncertainty is a little
higher, with the hurricane models (HAFS, HWRF) generally being
farther south than the global models. Very small changes were made
to the NHC track forecast, which is between the HCCA and simple
consensus aids.

As stated above, RI is occuring, and will likely continue today. The
question doesn't appear to be if RI continues, but rather how
strong Lee will get, and how quickly will it get there. Many of the
models are calling for remarkable rates of intensification, beyond
rates normally seen with model forecasts. Both HAFS models forecast
Lee to exceed 150 kt within the next 2 days, and even HCCA brings
the hurricane above the category 5 threshold. The NHC intensity
forecast has been shifted significantly higher, but is actually
within the guidance envelope. It should be stressed that internal
dynamics (eyewall replacement cycles) will become a factor with the
maximum strength of Lee as it becomes a major hurricane. This
is almost certain to lead to fluctuations in intensity that are
beyond our ability to forecast at these lead times. Hurricane Hunter
aircraft are scheduled to investigate Lee beginning this evening and
overnight, which should provide extremely useful information about
Lee's intensity during the coming days.


KEY MESSAGES:

1. Lee is forecast to become a major hurricane later today, with
its core moving north of the northern Leeward Islands, the Virgin
Islands, and Puerto Rico this weekend and early next week. The
potential for tropical storm conditions to occur in the islands is
decreasing, but residents there should continue to monitor updates
on Lee.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday, and the British and U.S. Virgin Islands,
Puerto Rico, Hispaniola, the Bahamas, and Bermuda this weekend.
These swells are likely to cause life-threatening surf and rip
current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 07/1500Z 16.4N 50.0W 90 KT 105 MPH
12H 08/0000Z 17.1N 51.7W 115 KT 130 MPH
24H 08/1200Z 18.2N 54.0W 130 KT 150 MPH
36H 09/0000Z 19.2N 56.1W 140 KT 160 MPH
48H 09/1200Z 20.1N 58.1W 140 KT 160 MPH
60H 10/0000Z 20.9N 59.8W 135 KT 155 MPH
72H 10/1200Z 21.5N 61.2W 135 KT 155 MPH
96H 11/1200Z 22.6N 63.7W 125 KT 145 MPH
120H 12/1200Z 23.6N 66.0W 120 KT 140 MPH

$$
Forecaster D. Zelinsky

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 10
NWS National Hurricane Center Miami FL AL132023
500 PM AST Thu Sep 07 2023

...LEE NOW A CATEGORY 4 HURRICANE...
...RIP CURRENTS AND HAZARDOUS SURF WILL SPREAD ACROSS THE NORTHERN
CARIBBEAN FRIDAY AND BEGIN AFFECTING THE MAINLAND U.S. BY SUNDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...16.9N 51.3W
ABOUT 780 MI...1260 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...953 MB...28.15 INCHES



Hurricane Lee Discussion Number 10
NWS National Hurricane Center Miami FL AL132023
500 PM AST Thu Sep 07 2023

Lee continues to strengthen at an exceptional rate. The hurricane
has quickly developed a clear symmetric eye surrounded by very cold
cloud tops. The intensity estimate of 115 kt is based primarily on
recent UW-CIMSS ADT intensity estimates near that value. The 102 kt
subjective Dvorak intensity estimates from TAFB and SAB at 18Z were
constrained by Dvorak rules, but both analyses noted that the Data-T
was higher. An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate Lee starting at 2330 UTC tonight, which
should provide much-needed in-situ data to better evaluate the
hurricane's intensity.

Low shear, very warm SSTs and copious moisture should allow Lee to
continue to rapidly strengthen at least tonight. All 4 regional
hurricane models (HAFS-A, HAFS-B, HWRF, HMON) forecast that Lee
will become a category 5 hurricane at some point in the next day or
so. In addition, the short-term rapid intensification probabilities
from SHIPS and DTOPS are still very high. Internal factors like
eyewall replacement cycles will become a factor soon, and these are
not easily predictable well in advance, but we don't yet see an
indication that Lee's intensification is stopping yet. The official
intensity forecast is quite close to the intensity consensus after
24 h, reflecting just how high several of the model forecasts are.

Confidence remains high in the track for Lee, with almost no change
made to the NHC track forecast. Lee should continue moving
west-northwestward along the southern edge of the subtropical ridge
for the next 5 days. The ridge is forecast to gradually weaken by
early next week, causing Lee to slow down. This track should keep
the core of Lee and its damaging winds north of the Leeward Islands.
There is uncertainty in any northward turn of Lee beginning early
next week, but it is too soon to speculate about specific potential
impacts a week or more out.

The biggest risk from Lee during the next 5 days will be high seas
and dangerous surf. Rip currents are likely to begin affecting
portions of the northern Caribbean on Friday. These conditions will
spread westward through the weekend, reaching most of the U.S. East
Coast by Sunday evening. For more information, please consult
products from your local weather office.


KEY MESSAGES:

1. Lee has become a major hurricane, and further strengthening is
expected, with its core moving north of the northern Leeward
Islands, the Virgin Islands, and Puerto Rico this weekend and early
next week.

2. Dangerous surf and life-threatening rip currents are likely in
the northern Leeward Islands beginning Friday. These conditions will
spread westward, affecting Puerto Rico, Hispaniola, the Turks
and Caicos, and the Bahamas through the weekend.

2. Dangerous surf and rip currents are expected along most of the
U.S. East Coast beginning Sunday. Please consult products from your
local weather office for more information.


FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 16.9N 51.3W 115 KT 130 MPH
12H 08/0600Z 17.6N 53.0W 140 KT 160 MPH
24H 08/1800Z 18.7N 55.2W 145 KT 165 MPH
36H 09/0600Z 19.7N 57.2W 140 KT 160 MPH
48H 09/1800Z 20.6N 59.0W 135 KT 155 MPH
60H 10/0600Z 21.3N 60.5W 135 KT 155 MPH
72H 10/1800Z 22.0N 61.8W 130 KT 150 MPH
96H 11/1800Z 23.1N 64.3W 130 KT 150 MPH
120H 12/1800Z 24.0N 66.4W 120 KT 140 MPH

$$
Forecaster D. Zelinsky

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 11
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Thu Sep 07 2023

...LEE BECOMES A CATEGORY 5 HURRICANE...
...DANGEROUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE
WESTERN ATLANTIC THROUGH EARLY NEXT WEEK...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.3N 52.4W
ABOUT 705 MI...1135 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...160 MPH...260 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...928 MB...27.41 INCHES




Hurricane Lee Discussion Number 11
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Thu Sep 07 2023

The Air Force Reserve Hurricane Hunters have found that Lee has
skyrocketed to category 5 strength. The aircraft measured peak
700-mb flight-level winds of 148 kt and trustworthy SFMR winds
slightly over 140 kt, and dropsonde data shows that the minimum
pressure has plummeted to 928 mb. Based on these data, the initial
intensity is set at 140 kt, and Lee's maximum winds have increased
by an incredible 70 kt over the past 24 hours. The hurricane has a
clear 15 n mi-wide eye, with an infrared eye temperature as warm
as 21 C surrounded by convective cloud tops as cold as -76 C.

Additional strengthening appears likely, as Lee remains in a
low-shear environment and over very warm waters near 30 degrees
Celsius, and there are no signs of an imminent eyewall replacement.
In fact, based on guidance from UW-CIMSS, the probability of a
secondary eyewall formation during the next 24 hours is well below
climatology. There is some chance that moderate deep-layer
southwesterly shear could develop over the hurricane, but this
could be offset by strong upper-level divergence and thus have
little to no impact. To account for the recent rate of
intensification, the NHC intensity forecast is slightly above the
IVCN and HCCA consensus aids and shows a peak intensity of 155 kt in
12 hours. Amazingly, the 1800 UTC HAFS-A and -B runs show a peak
intensity between 170-180 kt, but that's getting into rarefied air.
The NHC forecast will be adjusted accordingly if those solutions
begin looking like a more distinct possibility. Only very gradual
weakening is shown after 12-24 hours, and it is likely that Lee's
intensity will fluctuate for much of the forecast period. Lee is
forecast to remain a dangerous category 4 or 5 hurricane for the
next 5 days.

For the next 5 days--through next Tuesday evening--Lee is expected
to maintain a steady west-northwestward track, passing well to the
north of the northern Leeward Islands, the Virgin Islands, and
Puerto Rico. The hurricane is currently moving at about 12 kt, but
it is expected to slow down considerably through early next week as
the steering ridge to its north builds southwestward, effectively
blocking Lee's progress. The NHC track forecast remains of high
confidence through day 5, and again, no significant changes were
required from the previous forecast. Although there are some
indications that Lee might begin a northward turn around the middle
of next week, it is still way to soon to focus on specific model
scenarios that far out into the future.


KEY MESSAGES:

1. Lee has become a dangerous category 5 hurricane, and further
strengthening is forecast overnight. Lee's core is expected to move
well north of the northern Leeward Islands, the Virgin Islands, and
Puerto Rico this weekend and early next week.

2. Dangerous surf and life-threatening rip currents are likely in
the northern Leeward Islands beginning Friday. These conditions
will spread westward and northward, affecting Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda through
the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday. Continue to monitor updates to Lee's
forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0300Z 17.3N 52.4W 140 KT 160 MPH
12H 08/1200Z 18.1N 54.0W 155 KT 180 MPH
24H 09/0000Z 19.1N 56.1W 150 KT 175 MPH
36H 09/1200Z 20.1N 58.0W 145 KT 165 MPH
48H 10/0000Z 20.9N 59.6W 140 KT 160 MPH
60H 10/1200Z 21.5N 60.9W 135 KT 155 MPH
72H 11/0000Z 22.1N 62.2W 130 KT 150 MPH
96H 12/0000Z 23.2N 64.7W 125 KT 145 MPH
120H 13/0000Z 24.1N 66.6W 115 KT 130 MPH

$$
Forecaster Berg

[cycloneye]

[Div][BULLETIN
Hurricane Lee Advisory Number 12
NWS National Hurricane Center Miami FL AL132023
500 AM AST Fri Sep 08 2023

...POWERFUL CATEGORY 5 LEE EXPECTED TO MAINTAIN ITS INTENSITY...
...DANGEROUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE
WESTERN ATLANTIC THROUGH EARLY NEXT WEEK...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...17.8N 53.5W
ABOUT 630 MI...1015 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...165 MPH...270 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...926 MB...27.35 INCHES




Hurricane Lee Discussion Number 12
NWS National Hurricane Center Miami FL AL132023
500 AM AST Fri Sep 08 2023

Lee remains an extremely powerful category 5 hurricane. Satellite
images indicate that Lee has a symmetric inner core with a 10 n mi
circular and clear eye and no indications of concentric eyewalls
forming yet. Although the hurricane is incredibly powerful, its
wind field is not particularly large with its tropical-storm-force
winds extending roughly 100 n mi from the center. The Air Force
Hurricane Hunters investigated Lee earlier this morning and found
that the pressure has fallen to about 926 mb, based on dropsonde
data. In addition, the maximum 700-mb flight-level wind reported
was 153 kt and maximum surface SFMR wind was 158 kt, but this
estimate could be inflated. Blending these measurements, the
initial wind speed is nudged upward to 145 kt. Both the NOAA and
Air Force Hurricane Hunters will further investigate Lee in a couple
of hours.

Since Lee is expected to remain in favorable atmospheric conditions
while moving over even warmer waters during the next couple of days,
it seems likely that the hurricane will at least maintain its
intensity or become a little stronger during that time. The
dominant factor for Lee's short term intensity will be internal
dynamics, like eyewall replacement cycles. These conditions will
often cause fluctuations in the hurricane's strength, which are
challenging to forecast. There likely will be some weakening beyond
a few days when Lee moves over somewhat cooler waters and into an
environment of slightly higher shear. Regardless of the details,
Lee is expected to remain a powerful hurricane during the next
several days.

The major hurricane has been on a steady west-northwest path during
the past couple of days as it has been steered by the flow on the
south side of a subtropical ridge over the central Atlantic. A
continued west-northwest motion is expected, but at a progressively
slower pace during the forecast period as the ridge to the north of
the system weakens. The models are in fairly good agreement, and
little change was made to the previous NHC track forecast.

Lee is expected to increase in size and become more symmetric over
the weekend and early next week as the hurricane slows down. Recent
wave altimeter data showed peak significant wave heights between 45
and 50 feet near the center. Dangerously high seas are expected to
continue near the core of the hurricane, and large swells will
spread well away from the system through the forecast period.


KEY MESSAGES:

1. Lee is a dangerous category 5 hurricane, and further
strengthening is possible. Lee's core is expected to move well
north of the northern Leeward Islands, the Virgin Islands, and
Puerto Rico this weekend and early next week.

2. Dangerous surf and life-threatening rip currents are likely in
the northern Leeward Islands beginning later today. These
conditions will spread westward and northward, affecting Puerto
Rico, Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
through the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday. Continue to monitor updates to Lee's
forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 17.8N 53.5W 145 KT 165 MPH
12H 08/1800Z 18.6N 55.1W 155 KT 180 MPH
24H 09/0600Z 19.6N 57.1W 150 KT 175 MPH
36H 09/1800Z 20.5N 58.8W 145 KT 165 MPH
48H 10/0600Z 21.2N 60.2W 145 KT 165 MPH
60H 10/1800Z 21.9N 61.5W 140 KT 160 MPH
72H 11/0600Z 22.4N 62.7W 135 KT 155 MPH
96H 12/0600Z 23.3N 65.1W 130 KT 150 MPH
120H 13/0600Z 24.4N 67.1W 120 KT 140 MPH

$$
Forecaster Cangialosi

/Div]

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 13
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Fri Sep 08 2023

...LEE EXPECTED TO REMAIN A POWERFUL HURRICANE THROUGH EARLY NEXT
WEEK...
...DANGEROUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE
WESTERN ATLANTIC THROUGH EARLY NEXT WEEK...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.2N 54.5W
ABOUT 565 MI...910 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...155 MPH...250 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...942 MB...27.82 INCHES


Hurricane Lee Discussion Number 13
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Fri Sep 08 2023

The satellite presentation of Lee degraded somewhat this morning.
The small eye has become cloud filled and the overall cloud pattern
has become more asymmetric. There has been no indication of
concentric eyewalls so far, and the recent filling appears to be the
result of some moderate (15-20 kt) southwesterly shear as diagnosed
by a shear analysis from UW/CIMSS. Within the past hour or so, the
small eye has once again become a little better defined. Both NOAA
and Air Force Reserve Hurricane Hunter aircraft have been in the
storm this morning. The NOAA aircraft has measured a peak 8000 ft
flight-level wind of 143 kt, and the Air Force plane has found peak
700-mb flight level winds of 132 kt. SFMR surface estimates have
peaked in the 130-143 kt range. The pressure has risen to around
942 mb. Using a blend of these data the initial intensity is set at
135 kt. Fluctuations in intensity like what has occurred this
morning are not uncommon in intense hurricanes. Although Lee's
current intensity is lower than the overnight peak, the hurricane
remains very powerful.

The latest global model guidance suggests that the moderate shear
over the hurricane is likely to continue during the next day or
so. This along with potential eye wall replacement cycles are likely
to result in additional fluctuations in intensity during that
time, which are very difficult to time and predict. By later this
weekend, the upper-level wind pattern could become a little more
conducive and some restrengthening is possible. Regardless of exact
details of the intensity forecast, confidence is high that Lee will
remain a powerful hurricane during the next several days.

Lee has been moving west-northwestward at about 11 kt. The
hurricane should continued to be steered west-northwestward to the
south of a subtropical ridge over the central Atlantic. The
western extent of the ridge is forecast to weaken by early next
week, and Lee's forward speed is expected to slow considerably
around days 3-5. The track guidance continues to be tightly
clustered during the forecast period, and the NHC track is near
the middle of the guidance envelope.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are likely in
the northern Leeward Islands beginning today. These conditions
will spread westward and northward, affecting Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
through the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday. Continue to monitor updates to Lee's
forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 18.2N 54.5W 135 KT 155 MPH
12H 09/0000Z 19.0N 56.1W 135 KT 155 MPH
24H 09/1200Z 20.0N 57.9W 130 KT 150 MPH
36H 10/0000Z 20.8N 59.4W 125 KT 145 MPH
48H 10/1200Z 21.5N 60.8W 125 KT 145 MPH
60H 11/0000Z 22.1N 62.0W 125 KT 145 MPH
72H 11/1200Z 22.7N 63.1W 125 KT 145 MPH
96H 12/1200Z 23.5N 65.5W 120 KT 140 MPH
120H 13/1200Z 24.8N 67.5W 115 KT 130 MPH

$$
Forecaster Brown

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 14
NWS National Hurricane Center Miami FL AL132023
500 PM AST Fri Sep 08 2023

...CORE OF POWERFUL HURRICANE LEE EXPECTED TO PASS WELL NORTH OF
THE NORTHERN LEEWARD ISLANDS THIS WEEKEND...
...DANGEROUS SURF AND RIP CURRENT CONDITIONS EXPECTED TO DEVELOP
AROUND THE WESTERN ATLANTIC THROUGH EARLY NEXT WEEK...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.9N 55.5W
ABOUT 500 MI...805 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...942 MB...27.82 INCHES



TCDAT3

Hurricane Lee Discussion Number 14
NWS National Hurricane Center Miami FL AL132023
500 PM AST Fri Sep 08 2023

The small eye of Lee has become cloud filled this afternoon.
A 1643 UTC AMSR2 microwave overpass and the earlier reconnaissance
aircraft reports indicate that Lee's eye was a little less than
10 n mi in diameter. The microwave imagery revealed a well-defined
inner core but there was a lack of banding noted just outside the
core. This is likely due to some drier mid-level air that has
wrapped into the circulation. The Air Force Reserve Hurricane
Hunter aircraft did not find any stronger flight-level or SFMR winds
after the release of the previous advisory, and the initial
intensity for this advisory has been set at 130 kt. This is a blend
of the earlier reconnaissance data and subjective Dvorak intensity
estimates of T6.5 or 127 kt from TAFB and SAB. NOAA and Air Force
reconnaissance aircraft are scheduled to investigate Lee again this
evening.

The moderate shear and dry mid-level air that has affected Lee
today is not expected to abate during the next 12-24 hours. After
that time, the upper-level wind pattern could become a little more
conducive for re-strengthening. However, the timing of eyewall
replacement cycles makes it difficult to predict when Lee might
re-intensify. Although there is lower-than-normal confidence in
the exact details of the intensity forecast, there is high
confidence that Lee will remain a powerful hurricane into early next
week. The latest NHC wind speed forecast is a blend of the HFIP
corrected consensus model and the multi-model intensity consensus
aids.

Lee continues to move west-northwestward or 300 degrees at 11 kt.
A well-established mid- to upper-level ridge over the central
Atlantic should continue to steer the hurricane west-northward into
early next week. The ridge is forecast to build southwestward near
Bermuda late this weekend and early next week which is expected
cause Lee's forward speed to slow around 5-7 kt between days 2-4.
Late in the period, a mid-latitude trough that will be moving into
the Great Lakes Region is forecast to weaken the western portion of
the ridge, and Lee should begin to turn more poleward around that
time. The track guidance is still in good agreement through about
72 hours, but there is slightly more spread at days 4 and 5.
The spread is primarily related to speed differences in the guidance
during the latter portion of the forecast period. The latest NHC
track prediction is again close to the HCCA and TCVA consensus
aids, and it is very similar to the previous official forecast.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions
will spread westward and northward, affecting Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
through the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday. Continue to monitor
updates to Lee's forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 18.9N 55.5W 130 KT 150 MPH
12H 09/0600Z 19.7N 56.9W 125 KT 145 MPH
24H 09/1800Z 20.6N 58.6W 120 KT 140 MPH
36H 10/0600Z 21.3N 60.0W 120 KT 140 MPH
48H 10/1800Z 21.9N 61.3W 125 KT 145 MPH
60H 11/0600Z 22.5N 62.5W 125 KT 145 MPH
72H 11/1800Z 23.0N 63.7W 125 KT 145 MPH
96H 12/1800Z 23.7N 66.0W 120 KT 140 MPH
120H 13/1800Z 25.1N 67.6W 110 KT 125 MPH

$$
Forecaster Brown

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 15
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Fri Sep 08 2023

...AIR FORCE RESERVE AND NOAA HURRICANE HUNTERS FIND LEE NOT AS
STRONG BUT STILL A MAJOR HURRICANE...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN
ATLANTIC THROUGH NEXT WEEK...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.3N 56.5W
ABOUT 440 MI...705 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES




Hurricane Lee Discussion Number 15
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Fri Sep 08 2023

Strong southwesterly shear has taken a toll on Lee's structure.
The crews of ongoing NOAA and Air Force Reserve Hurricane Hunter
missions reported that the hurricane's eyewall has opened up, and
the satellite presentation has degraded significantly since earlier
today. Both planes have found the minimum pressure rising during
their missions, with the latest measurements being around 963 mb.
Based on this pressure and the planes' wind measurements, Lee's
initial intensity is set at 100 kt.

Moderate-to-strong deep-layer southwesterly shear is expected to
continue for at least the next 24 hours, if not longer. The GFS
model is the quickest to show the shear abating, but the ECMWF
now maintains shear over Lee for much of the forecast period. Most
of the intensity guidance shows Lee weakening further during the
next 12-24 hours while the shear is at its strongest, and that is
shown in the new NHC forecast. Despite the uncertainty in how
the upper-level pattern, and hence the shear profile, will evolve
around Lee, it is assumed that the atmospheric environment will
become at least a little more conducive for restrengthening after
24 hours. The NHC intensity forecast blends the latest IVCN
and HCCA consensus models with the previous official forecast,
particularly after 48 hours. Confidence in the intensity forecast
is low at the moment, although it is likely that Lee will remain a
dangerous hurricane for at least the next 5 days.

Lee's heading and speed remain 300 degrees at 11 kt. The
mid-tropospheric ridge to the north of the hurricane is forecast to
build to the west and southwest during the next few days, which
will keep Lee on a west-northwestward course with a decrease in
speed through next Tuesday. By Wednesday, a deep-layer trough is
forecast to amplify over the eastern United States, erode the
ridge, and cause Lee to gradually turn toward the northwest.
Although the track models agree on this general scenario, there is
disagreement on how far west Lee will get before it makes the turn.
To account for the latest suite of models, the NHC track forecast
has been shifted slightly westward on days 3 through 5, close to
the consensus aids but not as far west as the ECMWF, UKMET, and the
GEFS ensemble mean.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions
will spread westward and northward, affecting Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
through the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday. Continue to monitor
updates to Lee's forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0300Z 19.3N 56.5W 100 KT 115 MPH
12H 09/1200Z 20.0N 57.8W 95 KT 110 MPH
24H 10/0000Z 20.8N 59.4W 95 KT 110 MPH
36H 10/1200Z 21.5N 60.8W 105 KT 120 MPH
48H 11/0000Z 22.0N 62.0W 115 KT 130 MPH
60H 11/1200Z 22.5N 63.2W 120 KT 140 MPH
72H 12/0000Z 22.8N 64.2W 120 KT 140 MPH
96H 13/0000Z 23.5N 66.4W 120 KT 140 MPH
120H 14/0000Z 25.3N 67.7W 105 KT 120 MPH

$$
Forecaster Berg

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 16
NWS National Hurricane Center Miami FL AL132023
500 AM AST Sat Sep 09 2023

...LEE MAINTAINS MAJOR HURRICANE STATUS WHILE MOVING
WEST-NORTHWESTWARD...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN
ATLANTIC THROUGH NEXT WEEK...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...19.7N 57.4W
ABOUT 385 MI...620 KM ENE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES




Hurricane Lee Discussion Number 16
NWS National Hurricane Center Miami FL AL132023
500 AM AST Sat Sep 09 2023

Lee seems to be recovering from the effects of the strong
southwesterly shear. The central dense overcast has expanded, with
periodic bursts of deep convection and increased lightning activity
near the center. The most recent geostationary satellite infrared
images even seem to be hinting a return of Lee's eye. Overnight,
there were multiple reports from NOAA and Air Force Reserve
Hurricane Hunter aircraft of mesovorticies orbiting the closed,
elliptical eyewall. Due to safety considerations, the aircraft were
unable, at times, to penetrate the eyewall and thus, we have no new
in-situ information about the intensity or minimum central
pressure. The initial intensity is held at a somewhat uncertain
100 kt and NOAA and Air Force Reserve missions are scheduled to
investigate Lee later this morning.

Confidence in the intensity forecast remains low. Global models
suggest that Lee could be affected by strong-to-moderate
southwesterly shear for at least the next day, though the European
global model shows strong upper-level winds near the hurricane for
the entire forecast period. The statistical and consensus intensity
aids predict Lee could briefly weaken in the short-term, before
restrengthening in about 12-24 hours. Only minor adjustments have
been made to the latest NHC intensity forecast, which generally lies
between the simple and corrected consensus intensity aids.
Regardless of the details, it is likely that Lee will continue to be
a dangerous hurricane through the entire forecast period.

Lee is moving west-northwestward at 295/10 kt. The hurricane is
situated to the south of a mid-level ridge that is predicted to
build westward and southwestward during the next few days. This
steering pattern is expected to keep Lee on a west-northwestward
trajectory with a slower forward speed. By next Wednesday, the
hurricane should gradually turn to the northwest and
north-northwest in the flow between a trough over the eastern
United States and the southwestern edge of the ridge. While the
model guidance is in good agreement about the general synoptic
setup, there remain differences in how far west Lee will move
before it makes the turn. The latest NHC track forecast is very
similar to the previous predictions and lies just to the south of
the various track consensus aids.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions
will spread westward and northward, affecting Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
through the weekend.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday. Continue to monitor
updates to Lee's forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0900Z 19.7N 57.4W 100 KT 115 MPH
12H 09/1800Z 20.4N 58.7W 95 KT 110 MPH
24H 10/0600Z 21.2N 60.1W 95 KT 110 MPH
36H 10/1800Z 21.8N 61.4W 105 KT 120 MPH
48H 11/0600Z 22.4N 62.6W 115 KT 130 MPH
60H 11/1800Z 22.8N 63.7W 120 KT 140 MPH
72H 12/0600Z 23.2N 64.8W 120 KT 140 MPH
96H 13/0600Z 23.9N 66.8W 115 KT 130 MPH
120H 14/0600Z 25.7N 67.8W 105 KT 120 MPH

$$
Forecaster Bucci

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 17
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Sat Sep 09 2023

...NOAA AND AIR FORCE HURRICANE HUNTERS FIND LEE MAINTAINING ITS
STRENGTH...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN
ATLANTIC THROUGH NEXT WEEK...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.3N 58.2W
ABOUT 350 MI...565 KM ENE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...957 MB...28.26 INCHES



Hurricane Lee Discussion Number 17
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Sat Sep 09 2023

Satellite imagery shows that deep convection continues to pulse
near the center of Lee. Recent reports from reconnaissance
aircraft and an earlier SSMIS microwave image indicates that Lee
has a small (5 to 10 n-mi-wide) eye that is obscured by the
higher convective cloud tops. The NOAA P-3 Hurricane Hunter
aircraft penetrated the eye around 1013 UTC this morning and found
that the pressure was down a few millibars. The NOAA aircraft
measured peak SFMR surface winds of 100 kt, and 700-mb flight-level
winds of 103 kt. An Air Force Reserve reconnaissance aircraft
remains in the storm environment, but due to safety concerns was
not able to penetrate the northeastern eyewall on its first pass
through the storm due to very strong convection and mesovortices
orbiting the small eye. A recent center drop from the Air Force
plane suggest that the minimum pressure is around 957 mb. Drops
from both aircraft and Doppler radar data from the earlier NOAA
aircraft indicate that there is some southwest to northeast tilt
to the vortex. Based on the aircraft data, the initial intensity
remains 100 kt for this advisory.

There is still some question as to how conducive the upper-level
environment will be during the next few days. The GFS and regional
hurricane models indicate that the shear that has been affecting
Lee will decrease today, and that the upper-level wind pattern will
become much more favorable for restrengthening. Meanwhile, the
ECMWF and UKMET models depict a less favorable environment, with a
continuation of at least some moderate shear. The NHC forecast
follows the scenario that there will be at least some relaxation of
the shear and it calls for gradual restrengthening during the next
two to three days. The official wind speed forecast is not as high
as some of the dynamical model guidance, but is a blend of the HFIP
corrected consensus model and the IVCN multi-model consensus.

Lee is still moving west-northwestward or 300/10 kt. A mid-level
ridge located over the central Atlantic is forecast to build
west-southwestward during the next few days. This should keep Lee
on a general west-northwestward heading, but the building ridge is
expected to impede Lee's progress, and a much slower forward speed
is anticipated over the next several days. By Wednesday, Lee should
begin to turn northwestward, and then north-northwestward as a
mid-latitude trough moves into the Great Lakes region and eastern
United States. While the cross track spread in the guidance
remains fairly low, there is significant long track (forward speed)
spread in the models. The GFS and ECMWF depict similar overall
tracks, but the cross-track spread between those two typically
reliable models is more than 150 n mi by day 3. The NHC forecast
splits these speed differences and lies near the various consensus
aids.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions are
spreading westward and northward and will begin affecting Puerto
Rico, Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
later today and Sunday.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday. Continue to monitor
updates to Lee's forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 09/1500Z 20.3N 58.2W 100 KT 115 MPH
12H 10/0000Z 21.0N 59.3W 100 KT 115 MPH
24H 10/1200Z 21.7N 60.6W 105 KT 120 MPH
36H 11/0000Z 22.4N 61.9W 110 KT 125 MPH
48H 11/1200Z 22.9N 63.1W 115 KT 130 MPH
60H 12/0000Z 23.3N 64.2W 120 KT 140 MPH
72H 12/1200Z 23.6N 65.3W 120 KT 140 MPH
96H 13/1200Z 24.4N 67.0W 110 KT 125 MPH
120H 14/1200Z 26.8N 67.8W 105 KT 120 MPH

$$
Forecaster Brown

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 18
NWS National Hurricane Center Miami FL AL132023
500 PM AST Sat Sep 09 2023

...LEE TO PASS WELL NORTH OF THE LEEWARD ISLANDS DURING THE NEXT
DAY OR SO...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN
ATLANTIC THROUGH NEXT WEEK...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...20.7N 59.1W
ABOUT 310 MI...505 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...958 MB...28.29 INCHES



Hurricane Lee Discussion Number 18
NWS National Hurricane Center Miami FL AL132023
500 PM AST Sat Sep 09 2023

Lee's satellite presentation has changed little today. The center
is embedded within an area of cloud tops below -75C, and the Air
Force Reserve reconnaissance aircraft that was in the storm earlier
this afternoon continued to report that Lee has a small eye.
However, the eye remains obscured in both visible and infrared
satellite imagery. A blend of the flight-level and SFMR winds, as
well as dropsonde data from the earlier mission, yields an intensity
of around 100 kt, and the advisory intensity remains that value.
Dropsonde data in the center just before 1700 UTC supported a
minimum pressure of 958 mb. A NOAA P-3 aircraft is scheduled to be
in the storm environment again this evening to provide additional
information on the structure and strength of the hurricane.

Shear analysis from UW/CIMSS indicates that there is still about
15-20 kt of southwesterly shear over Lee. The GFS continues to
suggest that the shear will lessen during the next couple of days,
creating a more favorable environment for Lee to strengthen.
However, the ECMWF and UKMET still favor the notion that the
upper-level wind pattern will not become quite as conducive for a
couple of more days. Most of the intensity guidance calls for
gradual restrengthening and the NHC forecast follows suit. The NHC
intensity forecast is close to the consensus models, but not as
high as some of the dynamical model guidance and the HFIP corrected
consensus.

Satellite and aircraft fixes show that Lee is moving west-
northwestward at about 9 kt. There has been no change to the track
forecast philosophy. A mid-level ridge to the north of Lee is
foreast to shift west-southwestward during the next few days,
causing Lee's forward speed to slow considerably through early next
week. By midweek, a mid-latitude trough moving across the Great
Lakes region and into the eastern United States is expected to
weaken the ridge and allow Lee to turn north-northwestward and
northward on days 4 and 5. There is still a significant amount of
spread in the deterministic guidance and global model ensembles as
to exactly when and where the northward turn takes place. In fact,
the GFS and ECMWF models are about 275 n mi apart at day 5,
primarily due to along-track spread related to how fast Lee begins
moving northward. The NHC track forecast continues to lie near the
latest consensus aids, and the new track is very similar to the
previous forecast.

The center of Lee passed about 75 n mi south of NOAA buoy 41044 this
afternoon, and that buoy has reported peak 1-minute sustained winds
of 47 kt with a gust to 58 kt. That data along with a couple of
earlier scatterometer overpass have shown that the tropical-storm
force wind field has expanded outward over the eastern semicircle,
and that has been reflected in the latest analysis and forecast.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions are
spreading westward and northward and will affect Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda during
the next several days.

3. It remains too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to slow
down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday. Users should continue to
monitor updates to the forecast of Lee during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 09/2100Z 20.7N 59.1W 100 KT 115 MPH
12H 10/0600Z 21.4N 60.3W 105 KT 120 MPH
24H 10/1800Z 22.1N 61.6W 110 KT 125 MPH
36H 11/0600Z 22.9N 62.9W 115 KT 130 MPH
48H 11/1800Z 23.3N 64.1W 120 KT 140 MPH
60H 12/0600Z 23.6N 65.3W 120 KT 140 MPH
72H 12/1800Z 23.9N 66.3W 115 KT 130 MPH
96H 13/1800Z 25.1N 67.8W 105 KT 120 MPH
120H 14/1800Z 27.9N 68.2W 100 KT 115 MPH

$$
Forecaster Brown

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 19
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Sat Sep 09 2023

...LEE EXPECTED TO GROW IN SIZE OVER THE NEXT FEW DAYS...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN
ATLANTIC OVER THE UPCOMING WEEK...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...21.0N 59.9W
ABOUT 285 MI...455 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES




Hurricane Lee Discussion Number 19
NWS National Hurricane Center Miami FL AL132023
1100 PM AST Sat Sep 09 2023

While the geostationary satellite appearance of Lee has not changed
appreciably since the prior advisory, data from a NOAA P-3
reconnaissance mission in the storm, in addition to earlier GPM and
SSMIS microwave imagery, indicate that Lee is in the middle of an
eyewall replacement cycle (ERC). The aircraft has been reporting
both an inner and outer eyewall, with the outer eyewall gradually
contracting in size. However, this outer eyewall continues to
exhibit some asymmetry, consistent with modest vertical wind shear
still affecting the storm. In addition, the aircraft has reported
that the inner-core wind field is becoming weaker, but broader, with
a more muted wind profile outside of the radius of maximum wind.
This observation is also evident comparing TDR data between the
morning and evening NOAA-P3 missions. The peak 700 mb flight level
winds were down to 94 kt, with SFMR only in the 75-85 kt range. The
initial intensity has been adjusted to a somewhat generous 90 kt for
this advisory.

Lee continues to move west-northwestward this evening at 300/9 kt.
As discussed previously, the mid-level ridge axis currently north of
Lee is soon expected to shift to its west-southwest, resulting in
Lee slowing its forward motion, and perhaps making a slight westward
bend over the next 24-36 hours. Afterwards, an eastward-moving
mid-latitude trough is expected to erode this ridge and allow Lee to
turn northward by the end of the forecast period. There remains a
significant amount of spread in both the deterministic and ensemble
guidance on when this turn occurs, and then how quickly Lee
accelerates northward. For now the NHC track forecast remains
closest to the consensus aids, which have slowed a bit from the
prior cycle, and the latest track forecast is a bit slower but near
the same trajectory as the prior advisory.

While vertical wind shear over Lee appears to be gradual decreasing
over the system, the ongoing ERC seems to be resulting in the wind
field broadening versus allowing Lee to re-intensify so far.
However, once this cycle is complete, reintensification is still
anticipated, and the NHC intensity forecast still takes Lee back to
a category 4 hurricane in 36-48 hours, in good agreement with the
latest HAFS-A/B forecasts, which both explicitly show the ongoing
ERC. However, Lee's growing wind field, in combination with its
slowing forward motion, could make the hurricane susceptible to
feeling the effects of its own cold wake, which the
atmospheric-ocean coupled HAFS and HWRF models suggest could begin
to occur beyond 36 hours. Thus, the latest NHC intensity forecast
shows gradual weakening beginning by that time, with more pronounced
weakening by the end of the forecast period as the hurricane
traverses already cooled sea-surface temperatures from Franklin and
Idalia last week along its forecast track. This intensity forecast
is in good agreement with the simple consensus aids, but is a little
lower than the HFIP corrected consensus early on.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands. These conditions are
spreading westward and northward and will affect Puerto Rico,
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda during
the next several days.

3. It remains too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, especially since the hurricane is expected to slow
down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning tomorrow and continuing into next week as Lee
grows in size. Users should continue to monitor updates to the
forecast of Lee during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 10/0300Z 21.0N 59.9W 90 KT 105 MPH
12H 10/1200Z 21.6N 60.9W 100 KT 115 MPH
24H 11/0000Z 22.4N 62.3W 110 KT 125 MPH
36H 11/1200Z 23.0N 63.5W 120 KT 140 MPH
48H 12/0000Z 23.3N 64.7W 115 KT 130 MPH
60H 12/1200Z 23.6N 65.6W 110 KT 125 MPH
72H 13/0000Z 24.0N 66.6W 105 KT 120 MPH
96H 14/0000Z 25.6N 68.0W 95 KT 110 MPH
120H 15/0000Z 28.8N 68.3W 85 KT 100 MPH

$$
Forecaster Papin

[cycloneye]

BULLETIN
Hurricane Lee Advisory Number 20
NWS National Hurricane Center Miami FL AL132023
500 AM AST Sun Sep 10 2023

...LEE SLOWING DOWN OVER THE SOUTHWESTERN ATLANTIC...
...HAZARDOUS BEACH CONDITIONS EXPECTED TO SPREAD THROUGH THE WESTERN
ATLANTIC DURING THE WEEK...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...21.4N 60.5W
ABOUT 280 MI...450 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...958 MB...28.29 INCHES




Hurricane Lee Discussion Number 20
NWS National Hurricane Center Miami FL AL132023
500 AM AST Sun Sep 10 2023

Lee still seems to be feeling the effects of moderate southwesterly
wind shear, dry air, and internal structural changes. An Air Force
Reserve Hurricane Hunter aircraft reported earlier that the eyewall
had deteriorated to only a few curved bands. Geostationary
satellite imagery and earlier dropsonde data suggested that some dry
air is wrapping around the eastern and northern portion of the
circulation. The aircraft found maximum surface winds of 86 kt, and
a minimum central pressure of 957 mb. The initial intensity is held
at a possibly generous 90 kt based on these data.

The hurricane is moving to the west-northwest at 8 kt on the
southern side of a mid-level high pressure system. The high is
expected to build west-southwestward over the next day or so, which
should slow Lee's forward speed. By mid-week, a mid-latitude trough
is forecast to weaken the ridge and gradually turn Lee northward.
Global models differ significantly in the forward speed of the
hurricane, especially by the end of the forecast period. The
official track forecast is similar to the previous advisory and
generally favors the slower guidance, lying between the HCCA and
TCVN consensus aid.

A satellite analysis product from UW/CIMSS indicates that there is a
gradient of moderate-to-strong southwesterly shear over Lee. This
product suggests that the GFS, which is analyzing lower values of
shear, may not be accurately representing the environment near the
hurricane. Still, most of the model guidance predicts the shear
should relax, allowing Lee to strengthen in the next 36-48 h. The
latest intensity forecast has been lowered slightly from the
previous advisory, now showing a peak intensity of 115 kt. Beyond
day 2, environmental and oceanic conditions are expected to become
less conducive and cause Lee to gradually weaken. The NHC track
forecast remains in the middle of guidance envelop, near the various
consensus aids.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico early this
week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands and Puerto Rico. These
conditions are spreading westward and northward and will affect
Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda during
the next several days.

3. It remains too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, especially since the hurricane is expected to slow
down considerably over the southwestern Atlantic. Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning soon and continuing through the week as Lee
grows in size. Users should continue to monitor updates to the
forecast of Lee during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 10/0900Z 21.4N 60.5W 90 KT 105 MPH
12H 10/1800Z 22.0N 61.5W 95 KT 110 MPH
24H 11/0600Z 22.8N 62.8W 105 KT 120 MPH
36H 11/1800Z 23.3N 64.0W 115 KT 130 MPH
48H 12/0600Z 23.6N 65.2W 115 KT 130 MPH
60H 12/1800Z 23.9N 66.1W 110 KT 125 MPH
72H 13/0600Z 24.5N 66.9W 105 KT 120 MPH
96H 14/0600Z 26.5N 68.0W 95 KT 110 MPH
120H 15/0600Z 30.2N 68.0W 80 KT 90 MPH

$$
Forecaster Bucci