ATL: DANIELLE - Advisories

[Extratropical94]

Tropical Depression Five Advisory Number 1
NWS National Hurricane Center Miami FL AL052022
500 AM AST Thu Sep 01 2022

...NEW TROPICAL DEPRESSION FORMS OVER THE NORTH ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...38.1N 45.0W
ABOUT 975 MI...1575 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1013 MB...29.92 INCHES

FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 38.1N 45.0W 30 KT 35 MPH
12H 01/1800Z 38.2N 44.6W 35 KT 40 MPH
24H 02/0600Z 38.2N 44.2W 45 KT 50 MPH
36H 02/1800Z 38.1N 44.0W 55 KT 65 MPH
48H 03/0600Z 38.0N 44.3W 65 KT 75 MPH
60H 03/1800Z 38.0N 44.7W 70 KT 80 MPH
72H 04/0600Z 38.2N 45.1W 75 KT 85 MPH
96H 05/0600Z 39.5N 44.0W 80 KT 90 MPH
120H 06/0600Z 41.5N 42.5W 75 KT 85 MPH

That's roughly 8-9 ACE units over the next 5 days if the forecast materializes.

[Jelmergraaff]

Tropical Depression Five Advisory Number 1
NWS National Hurricane Center Miami FL AL052022
500 AM AST Thu Sep 01 2022

...NEW TROPICAL DEPRESSION FORMS OVER THE NORTH ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...38.1N 45.0W
ABOUT 975 MI...1575 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1013 MB...29.92 INCHES

FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 38.1N 45.0W 30 KT 35 MPH
12H 01/1800Z 38.2N 44.6W 35 KT 40 MPH
24H 02/0600Z 38.2N 44.2W 45 KT 50 MPH
36H 02/1800Z 38.1N 44.0W 55 KT 65 MPH
48H 03/0600Z 38.0N 44.3W 65 KT 75 MPH
60H 03/1800Z 38.0N 44.7W 70 KT 80 MPH
72H 04/0600Z 38.2N 45.1W 75 KT 85 MPH
96H 05/0600Z 39.5N 44.0W 80 KT 90 MPH
120H 06/0600Z 41.5N 42.5W 75 KT 85 MPH

That's roughly 8-9 ACE units over the next 5 days if the forecast materializes.

Pretty rare to see such an initial intensity forecast, especially considering where this cyclone has developed (38.1 N). The almost stationary position may be helping to intensify rather fast.

[cycloneye]

Tropical Depression Five Discussion Number 1
NWS National Hurricane Center Miami FL AL052022
500 AM AST Thu Sep 01 2022

Satellite imagery indicates that the low pressure area over the
North Atlantic west of the Azores has developed a well-defined
circulation and convective banding in the eastern semicircle. Based
on this structure, advisories are being initiated on Tropical
Depression Five with an initial intensity of 30 kt.

Despite the high latitude, the cyclone is in an area of light
steering currents on the southeast and south side of an anomalously
strong mid-level anticyclone. This should result in a slow motion
for the next three days or so, with the guidance showing an eastward
drift followed by a westward drift. After three days, the
anticyclone is forecast to move eastward and weaken as the
mid-latitude westerlies start encroaching on the system. The
large-scale models are not in good agreement with how this will
steer the cyclone, with the GFS and Canadian showing a general
motion toward the east while the UKMET and ECMWF forecast a more
northward motion. The track forecast is close to all of the
guidance for the first three days, and then calls for a
northeastward motion between the HFIP Corrected Consensus and the
other consensus models at days 4 and 5.

The sea surface temperatures in the area are warmer than normal -
near 27C. This warm water, combined with a forecast environment of
light- to moderate westerly shear for the next three days or so,
should allow steady strengthening. The intensity forecast calls for
the system to become a tropical storm later today, a hurricane in
about two days, and reach a peak intensity of 80 kt in about 4 days.
It should be noted that this forecast is close to the intensity
consensus, and there are models forecasting more intensification.
After four days, motion over cooler water and increasing shear
should cause the cyclone to weaken.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 38.1N 45.0W 30 KT 35 MPH
12H 01/1800Z 38.2N 44.6W 35 KT 40 MPH
24H 02/0600Z 38.2N 44.2W 45 KT 50 MPH
36H 02/1800Z 38.1N 44.0W 55 KT 65 MPH
48H 03/0600Z 38.0N 44.3W 65 KT 75 MPH
60H 03/1800Z 38.0N 44.7W 70 KT 80 MPH
72H 04/0600Z 38.2N 45.1W 75 KT 85 MPH
96H 05/0600Z 39.5N 44.0W 80 KT 90 MPH
120H 06/0600Z 41.5N 42.5W 75 KT 85 MPH

$$
Forecaster Beven

[Extratropical94]

Tropical Storm Danielle Discussion Number 2
NWS National Hurricane Center Miami FL AL052022
300 PM GMT Thu Sep 01 2022

A recent ASCAT pass revealed areas of tropical-storm-force winds and
the initial intensity is raised to 35 kt making the system Tropical
Storm Danielle. Visible satellite imagery also shows convective
coverage expanding and obscuring the low-level circulation.

The initial motion of the storm is eastward at 3 kt. The tropical
storm is located in an area of light winds and weak steering under
an omega block. This will likely cause the system to slowly drift
around the same general area until the anticyclone weakens and a
mid-latitude trough steers Danielle poleward around day 4. The
official track forecast is similar to the previous advisory
prediction and lies between the model consensus aids.

Danielle is over an area of warmer than average ocean waters.
Atmospheric conditions are also forecast to be relatively favorable,
with light- to moderate-northerly to northwesterly shear for the
next three days or so. The NHC forecast calls for additional
strengthening and Danielle is expected to become a hurricane in two
days and peak in intensity in about 4 days. When the storm moves
northward, Danielle will likely weaken as it moves over cooler sea
surface temperatures and the vertical wind shear increases.


FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 38.1N 44.7W 35 KT 40 MPH
12H 02/0000Z 38.2N 44.3W 40 KT 45 MPH
24H 02/1200Z 38.2N 44.0W 45 KT 50 MPH
36H 03/0000Z 38.1N 44.0W 55 KT 65 MPH
48H 03/1200Z 38.0N 44.2W 65 KT 75 MPH
60H 04/0000Z 38.0N 44.8W 70 KT 80 MPH
72H 04/1200Z 38.5N 44.9W 75 KT 85 MPH
96H 05/1200Z 40.0N 43.6W 80 KT 90 MPH
120H 06/1200Z 42.0N 42.0W 75 KT 85 MPH

$$
Forecaster Bucci/Cangialosi

[cycloneye]

Tropical Storm Danielle Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL052022
700 PM GMT Thu Sep 01 2022

...SATELLITE DATA INDICATE THAT DANIELLE IS STRENGTHENING
QUICKLY...

Satellite images indicate that the maximum winds associated with
Tropical Storm Danielle have increased to near 60 mph (95 km/h).

SUMMARY OF 700 PM GMT...1900 UTC...INFORMATION
----------------------------------------------
LOCATION...38.1N 44.6W
ABOUT 950 MI...1530 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...E OR 090 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

$$
Forecaster Bucci/Cangialosi

[cycloneye]

BULLETIN
Tropical Storm Danielle Advisory Number 3
NWS National Hurricane Center Miami FL AL052022
900 PM GMT Thu Sep 01 2022

...DANIELLE INTENSIFYING...


SUMMARY OF 900 PM GMT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...38.1N 44.5W
ABOUT 950 MI...1530 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


Tropical Storm Danielle Discussion Number 3
NWS National Hurricane Center Miami FL AL052022
900 PM GMT Thu Sep 01 2022

The high-latitude tropical cyclone has had quite the increase in
organization today. Recent microwave and visible satellite imagery
shows decent banding features and convection wrapping around the
low-level center. Subjective Dvorak classifications from TAFB and
SAB both estimate Danielle to be a 45-kt system. However, since the
storm has continued to improve in appearance, the initial intensity
has been increased to 50 kt.

Danielle is drifting eastward at 2 kt. A strong anticyclone over
the system is creating light and variable steering flow and Danielle
should continue to meander for the next few days. In about 4 days,
the anticyclone is expected to weaken and move eastward and a
mid-latitude trough should turn and accelerate Danielle to the
northeast. The NHC track forecast is shifted slightly westward from
the previous prediction and is close to the model consensus aids.

Atmospheric and oceanic conditions appear to be conducive for
additional strengthening during the next few days. The tropical
storm is over anomalously warm waters and global model guidance
indicates the vertical wind shear should gradually decrease over the
next few days. The official intensity forecast has been adjusted
upward based on the recent strengthening trend and now shows a peak
intensity of 85 kt in 60 hours. Thereafter, when Danielle is
forecast to turn northward, it is expected to gradually weaken over
cooler water temperatures and increased vertical wind shear.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 38.1N 44.5W 50 KT 60 MPH
12H 02/0600Z 38.1N 44.2W 60 KT 70 MPH
24H 02/1800Z 38.0N 44.1W 70 KT 80 MPH
36H 03/0600Z 38.0N 44.3W 75 KT 85 MPH
48H 03/1800Z 38.0N 44.7W 80 KT 90 MPH
60H 04/0600Z 38.2N 45.0W 85 KT 100 MPH
72H 04/1800Z 38.7N 44.9W 85 KT 100 MPH
96H 05/1800Z 40.5N 43.5W 80 KT 90 MPH
120H 06/1800Z 42.5N 41.7W 75 KT 85 MPH

$$
Forecaster Bucci/Cangialosi

[cycloneye]

BULLETIN
Tropical Storm Danielle Advisory Number 4
NWS National Hurricane Center Miami FL AL052022
300 AM GMT Fri Sep 02 2022

...DANIELLE CONTINUES TO STRENGTHEN...
...FORECAST TO BECOME THE SEASON'S FIRST HURRICANE ON FRIDAY...


SUMMARY OF 300 AM GMT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...38.0N 44.0W
ABOUT 925 MI...1485 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES



Tropical Storm Danielle Discussion Number 4
NWS National Hurricane Center Miami FL AL052022
300 AM GMT Fri Sep 02 2022

The overall organization of the tropical cyclone has continued to
increase since the previous advisory. The primary convective band
now wraps nearly completely around the center, and there have been
occasional hints of a ragged eye. Earlier microwave imagery also
revealed the presence of a ragged low- to mid-level eye feature.
Subjective Dvorak classifications have risen to T3.0 (45 kt) and
T3.5 (55 kt) from SAB and TAFB, respectively. Given the continued
improvement in structure, the intensity has been increased to 55 kt,
the higher end of those estimates.

Despite the high latitude of the tropical cyclone, atmospheric and
oceanic conditions are expected to remain favorable for additional
strengthening over the next 2-3 days. As mentioned previously, the
cyclone is located over anomalously warm waters, and the vertical
wind shear is forecast to remain generally low through 72 hours.
As a result, continued steady strengthening is expected, and
Danielle is forecast to become a hurricane on Friday. By days 4 and
5, cooler sea surface temperatures and increasing shear are likely
to cause some weakening. The NHC wind speed forecast is in good
agreement with the latest intensity consensus aids, and shows the
same peak intensity as the previous official forecast.

Danielle continues its slow eastward motion of around 090 degrees
at 2 kt. The cyclone is situated within an area of light steering
flow under an omega block, which is expected to cause Danielle to
meander during the next few days. The strong mid-level ridge to
the north is forecast to weaken and shift eastward early next week.
By days 4 and 5, an approaching mid-latitude trough should begin to
lift Danielle northeastward at an increasingly faster forward speed.
Little change was required to the early portion of the track
forecast, but the latter part has been adjusted eastward to be in
better alignment with the GFS and ECMWF ensemble means, and the
latest multi-model consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 38.0N 44.0W 55 KT 65 MPH
12H 02/1200Z 37.9N 43.8W 65 KT 75 MPH
24H 03/0000Z 37.9N 44.0W 70 KT 80 MPH
36H 03/1200Z 37.9N 44.3W 75 KT 85 MPH
48H 04/0000Z 38.0N 44.7W 80 KT 90 MPH
60H 04/1200Z 38.2N 44.9W 85 KT 100 MPH
72H 05/0000Z 38.9N 44.5W 85 KT 100 MPH
96H 06/0000Z 40.8N 42.4W 80 KT 90 MPH
120H 07/0000Z 42.6N 39.6W 75 KT 85 MPH

$$
Forecaster Brown

[cycloneye]

Tropical Storm Danielle Discussion Number 5
NWS National Hurricane Center Miami FL AL052022
900 AM GMT Fri Sep 02 2022

Satellite imagery shows that Danielle is continuing to strengthen,
with convective bands wrapping around the center and attempts at
eye formation. The various satellite intensity estimates have a
wide range from 45-77 kt, and the consensus of the estimates is
that Danielle is not quite a hurricane yet. Based on these
estimates, the initial intensity is increased to a possibly
conservative 60 kt.

Danielle continues to move slowly eastward, with the initial motion
100/3 kt. The cyclone is situated within an area of light steering
flow on the south side of an omega block mid-level anticyclone, and
this pattern is expected to cause Danielle to meander during the
next couple of days. After that, the blocking anticyclone should
move eastward and weaken, allowing the southern edge of the
mid-latitude westerlies to become the primary steering mechanism.
The large-scale models differ in the details of the shortwave
troughs in the westerlies that could affect Danielle, and due to
this the track guidance becomes somewhat divergent, with the ECMWF
calling for a more northward motion than the other guidance. The
new forecast track is similar to the previous forecast through 72
h, then is shifted a little to the north of the previous forecast.

The cyclone should remain over 26-27C sea surface temperatures for
about 72 h in an environment of light- to moderate westerly shear.
This should allow continued strengthening, with the main negative
factor being that the mid-level relative humidities near the
storm are low. After 72 h, movement over cooler water and
increased shear should cause weakening. However, the large-scale
models are in good agreement that the cyclone will not undergo
extratropical transition before the end of the forecast period.
The new intensity forecast is an update of the previous forecast
and lies near the intensity consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 37.9N 43.4W 60 KT 70 MPH
12H 02/1800Z 37.8N 43.4W 65 KT 75 MPH
24H 03/0600Z 37.8N 43.7W 70 KT 80 MPH
36H 03/1800Z 37.9N 44.2W 75 KT 85 MPH
48H 04/0600Z 38.2N 44.6W 80 KT 90 MPH
60H 04/1800Z 38.6N 44.4W 85 KT 100 MPH
72H 05/0600Z 39.2N 43.7W 85 KT 100 MPH
96H 06/0600Z 41.0N 41.4W 80 KT 90 MPH
120H 07/0600Z 42.5N 38.0W 75 KT 85 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Hurricane Danielle Advisory Number 6
NWS National Hurricane Center Miami FL AL052022
300 PM GMT Fri Sep 02 2022

...DANIELLE BECOMES THE FIRST ATLANTIC HURRICANE OF THE SEASON...


SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...37.9N 43.3W
ABOUT 885 MI...1425 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 1 MPH...2 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES


Hurricane Danielle Discussion Number 6
NWS National Hurricane Center Miami FL AL052022
300 PM GMT Fri Sep 02 2022

Danielle has continued to strengthen this morning. A ragged eye is
evident in conventional satellite imagery, and deep convection
surrounds much of the northern and western portions of the
circulation. A recent ASCAT-B pass missed the center but caught the
eastern portion of the circulation. It showed winds up to 52 kt on
the inner edge of the swath and tropical-storm-force winds extending
outward up to 100 n mi in the northeastern quadrant of the cyclone.
The latest objective and subjective satellite estimates support
raising the initial intensity to 65 kt, which makes Danielle the
first Atlantic hurricane of the season.

Atmospheric and oceanic conditions appear generally favorable for
some additional strengthening during the next couple of days. The
hurricane will meander over 27C SSTs in an environment of light to
moderate deep-layer shear. Danielle is a higher-latitude storm, and
so there is the potential for some mid-level dry air entrainment
that could briefly disrupt the cyclone's organization. The latest
intensity guidance consensus still favors some additional
strengthening through Sunday. The official NHC forecast is similar
to the previous one and lies slightly above the model consensus.
After 72 h, weakening is expected to commence as Danielle gains
latitude and moves over cooler waters while it encounters more
deep-layer shear within the mid-latitude westerlies.

Although the 12-hr motion of Danielle has been an easterly drift,
the hurricane appears to have become nearly stationary this
morning. The cyclone will likely continue to meander over the
central Atlantic during the next couple of days under the influence
of a blocking high pressure ridge. This feature is forecast to
weaken by early next week, which should allow Danielle to begin
moving northeastward by 72 h and accelerate deeper into the
mid-latitudes on days 4-5. Once again, it appears Danielle will not
begin extratropical transition until beyond the end of the forecast
period. The NHC track forecast generally lies near the center of
the guidance envelope, close to the reliable consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 02/1500Z 37.9N 43.3W 65 KT 75 MPH
12H 03/0000Z 38.0N 43.3W 70 KT 80 MPH
24H 03/1200Z 38.1N 43.5W 75 KT 85 MPH
36H 04/0000Z 38.1N 44.0W 80 KT 90 MPH
48H 04/1200Z 38.5N 44.4W 85 KT 100 MPH
60H 05/0000Z 38.9N 44.1W 85 KT 100 MPH
72H 05/1200Z 39.6N 43.1W 85 KT 100 MPH
96H 06/1200Z 41.0N 40.5W 80 KT 90 MPH
120H 07/1200Z 42.5N 36.4W 70 KT 80 MPH

$$
Forecaster Reinhart

[cycloneye]

BULLETIN
Hurricane Danielle Advisory Number 7
NWS National Hurricane Center Miami FL AL052022
900 PM GMT Fri Sep 02 2022

...DANIELLE NEARLY STATIONARY OVER THE OPEN CENTRAL ATLANTIC...


SUMMARY OF 900 PM GMT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...37.9N 43.5W
ABOUT 895 MI...1445 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES


Hurricane Danielle Discussion Number 7
NWS National Hurricane Center Miami FL AL052022
900 PM GMT Fri Sep 02 2022

The satellite presentation of Danielle has degraded some this
afternoon. Drier mid-level air appears to have wrapped into the
circulation, and the cyclone now has more of a banded structure
around the western and southern portions of the system. Recently,
infrared cloud top temperatures have cooled within a small ring of
inner core convection. Based on a blend of the subjective Dvorak
estimates from SAB and TAFB, the initial intensity is held at 65 kt
for this advisory.

Danielle is nearly stationary, as it remains under weak steering
currents with a blocking high pressure ridge positioned over the
North Atlantic. The cyclone is expected to meander or drift slowly
westward over the next couple of days. As the ridge weakens and
retreats westward, Danielle should begin moving northeastward
more-typical mid-latitude flow by Monday. Then, the cyclone is
forecast to gradually accelerate northeastward during the middle of
next week. The track guidance has shifted considerably to the left
this cycle, and the latest NHC track forecast has been adjusted in
this direction, toward the HFIP corrected consensus (HCCA).

The upwelling of cooler water underneath slow-moving Danielle is
likely to prevent much strengthening in the near term. However, the
deep-layer shear is expected to remain weak for the next couple of
days. So, there is still potential for a bit of strengthening if the
cyclone is able to drift farther west of its current position. By
72 h, Danielle is forecast to cross the 26C isotherm and move into
a more highly-sheared environment, which is expected to induce a
weakening trend through the rest of the forecast period. The latest
NHC intensity forecast has been lowered from the previous one and
lies near or just below the various model consensus aids. Around day
5, Danielle is forecast to interact with an upper-level trough and
begin the process of extratropical transition.


FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 37.9N 43.5W 65 KT 75 MPH
12H 03/0600Z 38.0N 43.7W 65 KT 75 MPH
24H 03/1800Z 38.0N 44.2W 65 KT 75 MPH
36H 04/0600Z 38.1N 44.6W 70 KT 80 MPH
48H 04/1800Z 38.3N 44.9W 75 KT 85 MPH
60H 05/0600Z 39.0N 44.3W 75 KT 85 MPH
72H 05/1800Z 39.6N 43.6W 75 KT 85 MPH
96H 06/1800Z 41.5N 41.0W 70 KT 80 MPH
120H 07/1800Z 43.0N 37.0W 65 KT 75 MPH

$$
Forecaster Reinhart

[cycloneye]

Hurricane Danielle Discussion Number 8
NWS National Hurricane Center Miami FL AL052022
300 AM GMT Sat Sep 03 2022

Danielle's satellite presentation has degraded further this
evening, highlighted by a loss of the eye. Dvorak T-numbers have
decreased from TAFB and SAB since earlier today, but their
respective Current Intensity numbers remain 4.0 and 4.5.
Therefore, the initial intensity is being held at 65 kt.

Danielle has been stationary for the past 6-12 hours while it
remains in a weak steering environment to the south of a blocking
high over the North Atlantic. This pattern is expected to hold
firm for the next few days, with the hurricane forecast to meander
through about day 3. After that time, a deep-layer trough moving
off the coast of Atlantic Canada and the northeastern U.S. should
finally shove Danielle on an accelerating path toward the northeast
on days 4 and 5. During the acceleration phase, the updated NHC
track forecast is a little north of the previous forecast and lies
close to the HCCA, TVCN, and FSSE multi-model consensus aids.

Danielle's convective and organizational struggles during the past
few hours could be due to upwelling of cooler waters. While
vertical shear is expected to be generally low 3 days or so, the
hurricane's slow motion is likely to continue to upwell cooler
waters, and therefore only slight strengthening is anticipated
during that time. Danielle is expected to move over colder waters
after day 3, which should induce some weakening toward the end of
the forecast period. Global models also suggest that the
cyclone could be undergoing extratropical transition by the end
of the forecast period. The updated NHC intensity forecast is very
similar to the previous forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 03/0300Z 37.9N 43.5W 65 KT 75 MPH
12H 03/1200Z 38.0N 43.9W 65 KT 75 MPH
24H 04/0000Z 37.9N 44.5W 70 KT 80 MPH
36H 04/1200Z 38.1N 44.8W 70 KT 80 MPH
48H 05/0000Z 38.7N 44.6W 75 KT 85 MPH
60H 05/1200Z 39.4N 44.1W 75 KT 85 MPH
72H 06/0000Z 40.2N 43.5W 75 KT 85 MPH
96H 07/0000Z 42.1N 41.2W 70 KT 80 MPH
120H 08/0000Z 45.5N 36.5W 65 KT 75 MPH

$$
Forecaster Berg

[cycloneye]

Tropical Storm Danielle Discussion Number 9
NWS National Hurricane Center Miami FL AL052022
900 AM GMT Sat Sep 03 2022

Convection associated with Danielle has continued to decrease this
morning, with a corresponding decrease in satellite intensity
estimates. Based on this decrease, it is estimated that Danielle
has weakened to a tropical storm with an initial intensity of 60 kt.
While it is not known why the storm has weakened, one possibility
is that the slow motion has allowed the cyclone to upwell cold
water underneath it.

Danielle is essentially stationary with a 12-h motion of 270/1 kt.
The cyclone is still caught south of a blocking high over the North
Atlantic. This pattern is expected to hold firm for a couple of
days, with the system forecast to drift westward and then drift
northward. After 48-60 h, the block will weaken and allow the
southern edge of the mid-latitude westerlies to steer Danielle
generally northeastward at a faster forward speed. There are no
significant changes to the forecast track for the first 48-60 h.
After that, the forecast has been nudged eastward due to a shift
in the guidance envelope.

The intensity guidance is still calling for Danielle to strengthen
for 72 h or so. Given the possibility of upwelling and the
forecast continued slow motion, the guidance might be a bit
optimistic on that. The new intensity forecast calls for little
change in strength for 12 h or so, followed by slow strengthening
on the premise that the storm will move over somewhat warmer water.
After 72 h, the storm is likely to interact with an upper-level
trough, which could help maintain the intensity even as Danielle
moves toward much colder water in the North Atlantic. This trough
will also start extratropical transition, although this will
likely not be complete by 120 h.


FORECAST POSITIONS AND MAX WINDS

INIT 03/0900Z 38.0N 43.8W 60 KT 70 MPH
12H 03/1800Z 38.0N 44.1W 60 KT 70 MPH
24H 04/0600Z 38.1N 44.7W 65 KT 75 MPH
36H 04/1800Z 38.5N 44.7W 70 KT 80 MPH
48H 05/0600Z 39.1N 44.3W 75 KT 85 MPH
60H 05/1800Z 39.9N 43.6W 75 KT 85 MPH
72H 06/0600Z 40.7N 42.6W 75 KT 85 MPH
96H 07/0600Z 43.0N 39.5W 70 KT 80 MPH
120H 08/0600Z 46.5N 35.5W 65 KT 75 MPH

$$
Forecaster Beven

[cycloneye]

Tropical Storm Danielle Discussion Number 10
NWS National Hurricane Center Miami FL AL052022
300 PM GMT Sat Sep 03 2022

Satellite images indicate that Danielle has generally changed little
during the past several hours. The storm is still producing bands
of deep convection, especially on its north side, but there are dry
slots that have entrained into the south side of the circulation.
The Dvorak estimates from TAFB and SAB range from 55 to 65 kt, and
based on that data, the initial intensity is held at 60 kt.

Danielle has been moving very slowly to the west-northwest at 2 kt
and is back over the same location where it was 24-36 hours ago. A
continued slow west-northwestward motion is expected through tonight
as the storm remains steered by a blocking ridge to its north.
However, a sharp turn to the north is forecast on Sunday followed by
a faster motion to the northeast after that as a trough currently
over eastern Canada approaches Danielle. Although the models agree
on the overall scenario, there is a fair amount of spread on where
and how sharply the storm is expected to turn. The NHC track
forecast is a little to the west of the previous one in the short
term, but ends up near the previous forecast from 48 to 120 h, and
it lies roughly near the middle of the guidance envelope.

Danielle has been over its own cool SSTs wake during the past 12-18
hours, which possibly caused the observed slight weakening.
However, as the storm pulls away from that area and remains in
generally favorable atmospheric conditions, Danielle will likely
restrengthen during the next couple of days. Beyond that time,
cooler waters, drier air, and an increase in shear should cause some
weakening. Danielle is expected to become an extratropical cyclone
by the end of the forecast period when it merges with the
approaching trough and moves over SSTs near 20C. The NHC intensity
forecast is just an update of the previous one and in line with the
HCCA and IVCN consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 03/1500Z 38.1N 44.0W 60 KT 70 MPH
12H 04/0000Z 38.2N 44.5W 60 KT 70 MPH
24H 04/1200Z 38.4N 44.8W 65 KT 75 MPH
36H 05/0000Z 38.9N 44.7W 70 KT 80 MPH
48H 05/1200Z 39.7N 44.1W 75 KT 85 MPH
60H 06/0000Z 40.6N 43.2W 75 KT 85 MPH
72H 06/1200Z 41.5N 42.1W 70 KT 80 MPH
96H 07/1200Z 43.8N 38.3W 65 KT 75 MPH
120H 08/1200Z 46.8N 33.4W 60 KT 70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Cangialosi

[cycloneye]

Tropical Storm Danielle Discussion Number 11
NWS National Hurricane Center Miami FL AL052022
900 PM GMT Sat Sep 03 2022

Danielle's cloud pattern has become better organized during the
past several hours with banding features gaining symmetry around
the center. However, there are still some dry slots disrupting
the system's inner core. A blend of the latest satellite intensity
estimates still supports an intensity of 60 kt, but Danielle could
become a hurricane again soon. An ASCAT pass from several
hours ago was helpful in adjusting the initial 34- and 50-kt wind
radii.

The storm has been moving a little faster to the west at 5 kt and is
back over the same location where it was on Thursday. A continued
slow westward motion is expected into Sunday as the storm remains
steered by a blocking ridge to its north. However, a sharp turn to
the north is forecast by Sunday night followed by a faster motion to
the northeast after that as a trough currently over eastern Canada
approaches Danielle. The new NHC track forecast has been adjusted
to the left in the short term, but ends up to the east of the
previous track at 96 and 120 h, trending toward the latest
consensus aids.

Danielle is expected to gradually pull away from its own cool SST
wake, and since the atmospheric conditions appear generally
favorable, slow strengthening seems likely during the next day or
two. Beyond a couple of days, however, sharply cooler SSTs, drier
air, and an increase in vertical wind shear should end the
strengthening trend and induce some weakening. Danielle is expected
to become fully extratropical by day 5 when it merges with the
approaching trough and moves over SSTs cooler than 20C. The NHC
intensity forecast is again an update of the previous one and
remains in line with the HCCA and IVCN consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 03/2100Z 38.0N 44.8W 60 KT 70 MPH
12H 04/0600Z 38.1N 45.3W 65 KT 75 MPH
24H 04/1800Z 38.4N 45.4W 70 KT 80 MPH
36H 05/0600Z 39.0N 44.9W 75 KT 85 MPH
48H 05/1800Z 39.9N 44.1W 75 KT 85 MPH
60H 06/0600Z 40.8N 43.2W 75 KT 85 MPH
72H 06/1800Z 41.7N 41.7W 70 KT 80 MPH
96H 07/1800Z 44.2N 36.9W 65 KT 75 MPH
120H 08/1800Z 46.7N 30.7W 60 KT 70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Cangialosi

[cycloneye]

Hurricane Danielle Discussion Number 12
NWS National Hurricane Center Miami FL AL052022
1100 PM AST Sat Sep 03 2022

Danielle has, once again, become a hurricane. The satellite
presentation consists of a single, primary curved band wrapping
around approximately 95 percent of the surface circulation center.
The Dvorak satellite intensity estimates from TAFB and SAB are
a unanimous T-4.0, yielding 65 kt which is the initial intensity
for this advisory.

The environment appears conducive for gradual strengthening during
the short term. Beyond the 48-hour period, however, decreasing
oceanic temperatures, an increasingly stable environment, and
increasing vertical wind shear should induce a slow weakening trend.
The latest Florida State Cyclone Phase Analysis, using the GFS,
shows Danielle commencing an extratropical transition on the 6th. In
that model, the cyclone maintains a moderate to deep warm core but
becomes highly asymmetric (frontal characteristics) in the lower
troposphere around the 8th. The analysis and the SHIPS statistical
intensity model show Danielle completing its transition near the end
of the 5-day forecast period with a well-developed cold core above
600 mb. The NHC forecast follows suit and shows Danielle as an
extratropical cyclone at 120 h. The official intensity forecast now
shows a peak intensity of 80 kt in 36 hours and agrees with the NOAA
HCCA and IVCN intensity consensus aids.

Danielle has been drifting toward the west during the past several
hours and this general motion is expected to continue through
Sunday as the hurricane remains in weak steering currents to the
south of high pressure anchored over the North Atlantic.
Afterward, a turn to the north is forecast by Sunday night,
followed by an acceleration toward the northeast in response to a
deep-layer trough moving over the Canadian Maritimes and toward
Danielle. The NHC forecast is an update of the previous one
through 72 hours, and is adjusted slightly south to lie closer to
the various consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT 04/0300Z 38.1N 45.1W 65 KT 75 MPH
12H 04/1200Z 38.2N 45.4W 70 KT 80 MPH
24H 05/0000Z 38.7N 45.1W 75 KT 85 MPH
36H 05/1200Z 39.5N 44.4W 80 KT 90 MPH
48H 06/0000Z 40.4N 43.5W 80 KT 90 MPH
60H 06/1200Z 41.4N 42.2W 75 KT 85 MPH
72H 07/0000Z 42.4N 40.2W 70 KT 80 MPH
96H 08/0000Z 44.5N 35.0W 65 KT 75 MPH
120H 09/0000Z 46.1N 28.4W 60 KT 70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Roberts

[cycloneye]

Hurricane Danielle Discussion Number 13
NWS National Hurricane Center Miami FL AL052022
500 AM AST Sun Sep 04 2022

There has been little overall change in the satellite presentation
of Danielle overnight. Curved convective bands wrap around the
center, with a large ragged banded eye-like feature evident at
times. There is a large range in the satellite intensity estimates
this morning with objective estimates much lower than the
subjective Dvorak T-numbers from TAFB and SAB. Although the SAB
Dvorak estimate increased to T4.5 (77 kt) at 06Z, given the general
steady state of the system's organization since the previous
advisory, the initial intensity remains 65 kt, which is a blend of
the various estimates and is in agreement with the latest TAFB
Dvorak satellite classification.

Danielle is forecast to remain over SSTs of around 27C and in a low
shear environment during the next 24 to 36 hours. As a result,
most of the intensity guidance calls for some intensification
during that time, and the NHC forecast follows suit. After that
time, gradually decreasing sea surface temperatures along the
forecast track should cause slow weakening. By days 4 and 5,
increasing shear and the system's transition into a post-tropical
cyclone are likely to cause additional weakening. The NHC
intensity forecast is a blend of the IVCN and HFIP corrected
consensus models.

The hurricane has been meandering overnight but a slow northward
motion should begin this morning. Danielle is forecast to
gradually accelerate to the northeast beginning on Monday as
deep-layer trough moves over eastern Canada. By 72 hours, the
storm should turn east-northeastward within the mid-latitude
westerly flow. The latest dynamical model guidance predicts a
slightly faster motion over much of the forecast period, and the
NHC forecast has been adjusted accordingly. The new forecast is not
as fast as the TCVA consensus model, therefore future modifications
regarding the forward speed of the cyclone may be required.

FORECAST POSITIONS AND MAX WINDS

INIT 04/0900Z 38.1N 45.2W 65 KT 75 MPH
12H 04/1800Z 38.5N 45.1W 70 KT 80 MPH
24H 05/0600Z 39.2N 44.6W 75 KT 85 MPH
36H 05/1800Z 40.3N 43.7W 80 KT 90 MPH
48H 06/0600Z 41.2N 42.4W 75 KT 85 MPH
60H 06/1800Z 42.1N 40.6W 75 KT 85 MPH
72H 07/0600Z 43.1N 38.1W 70 KT 80 MPH
96H 08/0600Z 45.3N 32.0W 60 KT 70 MPH
120H 09/0600Z 47.1N 23.7W 50 KT 60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown

[cycloneye]

Hurricane Danielle Discussion Number 14
NWS National Hurricane Center Miami FL AL052022
1100 AM AST Sun Sep 04 2022

Danielle has slightly improved in satellite presentation this
morning. First-light visible imagery still showed a ragged eye that
could be trying to clear out. Subjective intensity estimates from
TAFB and SAB remain at 77 kt, and the objective estimates have
risen, though are still somewhat lower. The initial intensity has
been increased to 70 kt to represent a blend of the latest
classifications.

The hurricane is expected to be over relatively warm waters and in a
region with low vertical wind shear for about another day. These
oceanic and atmospheric factors should allow Danielle to gradually
strengthen. Thereafter, the storm is forecast to move over cooler
waters and encounter moderate deep-layer wind shear which will
likely result in weakening. The NHC intensity forecast is similar
to the previous advisory and close to the consensus model aids.
Danielle is still expected to become an extratropical cyclone in
about 5 days.

Danielle is still drifting in the Central Atlantic with the latest
motion estimated at 270/1 kt, but model guidance insists a turn to
the north should occur today ahead of a mid-latitude trough over
eastern Canada. Then Danielle is expected to turn northeast with an
accelerated forward motion in about a day. The storm should then
turn east-northeastward within the mid-latitude westerly flow in a
few days. The latest forecast is similar to the previous advisory in
terms of location with a slightly accelerated along-track motion.


FORECAST POSITIONS AND MAX WINDS

INIT 04/1500Z 38.1N 45.3W 70 KT 80 MPH
12H 05/0000Z 38.6N 45.1W 75 KT 85 MPH
24H 05/1200Z 39.5N 44.3W 80 KT 90 MPH
36H 06/0000Z 40.6N 43.2W 75 KT 85 MPH
48H 06/1200Z 41.5N 41.5W 75 KT 85 MPH
60H 07/0000Z 42.5N 39.3W 70 KT 80 MPH
72H 07/1200Z 43.5N 36.3W 70 KT 80 MPH
96H 08/1200Z 45.5N 29.5W 60 KT 70 MPH
120H 09/1200Z 46.7N 21.7W 50 KT 60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Bucci/Cangialosi

[cycloneye]

Hurricane Danielle Discussion Number 15
NWS National Hurricane Center Miami FL AL052022
500 PM AST Sun Sep 04 2022

Danielle's satellite presentation continues to gradually improve.
A microwave pass from earlier this afternoon showed a well-defined
band wrapping around most the center of circulation and only open
to the south. While a scatterometer pass missed the inner core, it
did measure the periphery of the hurricane and revealed that the
tropical-storm-force winds over the eastern semicircle of the
circulation extended slightly less from the center than previously
estimated. The subjective Dvorak intensity estimates from TAFB and
SAB were both 77 kt, and therefore the initial intensity is
increased to 75 kt.

There is still about a 24-hour window in which global model
guidance suggests oceanic and atmospheric conditions should be
conducive for slight strengthening. Danielle is expected to begin
weakening beyond 24 hours when the system traverses cooler ocean
surface temperatures and encounters stronger deep-layer wind shear.
The official intensity forecast now shows Danielle reaching its peak
intensity in 12 hours. The system is still expected to become a
post-tropical cyclone in 5 days.

The hurricane appears to be making its anticipated turn to the
north with a motion of 360/2 kt. Over the next few days,
Danielle is expected to turn to the northeast and accelerate ahead
of a trough currently located over eastern Canada. As the storm
reaches higher latitudes, it will likely turn east-northeastward in
the mid-latitude westerlies. The NHC track forecast is very similar
to the previous prediction and lies closest to the correct consensus
model aid.


FORECAST POSITIONS AND MAX WINDS

INIT 04/2100Z 38.5N 45.1W 75 KT 85 MPH
12H 05/0600Z 39.1N 44.7W 80 KT 90 MPH
24H 05/1800Z 40.2N 43.7W 80 KT 90 MPH
36H 06/0600Z 41.2N 42.3W 75 KT 85 MPH
48H 06/1800Z 42.1N 40.4W 75 KT 85 MPH
60H 07/0600Z 42.9N 37.9W 70 KT 80 MPH
72H 07/1800Z 44.0N 34.9W 65 KT 75 MPH
96H 08/1800Z 45.9N 27.6W 55 KT 65 MPH
120H 09/1800Z 47.0N 19.6W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Bucci/Cangialosi

[cycloneye]

Hurricane Danielle Discussion Number 16
NWS National Hurricane Center Miami FL AL052022
300 AM GMT Mon Sep 05 2022

Danielle has become better organized during the past several hours.
GOES-16 ProxyVis and BD-curve enhanced IR imagery show a much
improved inner core structure with a clear warm 14C eye. The cloud
pattern also comprises a well-developed outer curved band with -65C
cloud tops. A blend of the subjective and UW-CIMSS objective
satellite intensity estimates raises the initial intensity to 80 kt
for this advisory.

Danielle is forecast to remain over SSTs of around 26-27C and in a
low-shear environment during the next 36 hours. As a result,
the statistical SHIPS intensity model and the intensity consensus
aids call for Danielle to maintain its current intensity during
that time, and the NHC forecast follows suit. Beyond 36 hours,
gradually decreasing oceanic surface temperatures along the
forecast track and increasing southwesterly shear should
weaken the cyclone. The latest Florida State Cyclone Phase
Analysis shows that the UKMET and the GFS agree with Danielle
commencing an extratropical transition around 48 hours.
The analysis also indicates that Danielle will complete its
transition by 96 hours (Thursday evening), and this
cyclone transformation is shown in the official forecast.

The hurricane's initial motion is estimated to be northeastward
and at a slightly faster pace of 6 kt. Danielle should continue to
accelerate northeastward during the next 36 hours in response to a
mid-latitude major shortwave trough approaching from the northwest,
out of the Canadian Maritimes. By Tuesday night, the storm should
turn toward the east-northeast within the mid-latitude westerlies
and continue in this general heading through the period. The NHC
track forecast has been adjusted north of the previous advisory
beyond 60 hours to agree more with the TVCA and HCCA consensus
solutions.


FORECAST POSITIONS AND MAX WINDS

INIT 05/0300Z 39.0N 44.7W 80 KT 90 MPH
12H 05/1200Z 39.8N 44.1W 80 KT 90 MPH
24H 06/0000Z 40.9N 43.0W 80 KT 90 MPH
36H 06/1200Z 41.7N 41.4W 75 KT 85 MPH
48H 07/0000Z 42.4N 39.2W 75 KT 85 MPH
60H 07/1200Z 43.3N 36.6W 70 KT 80 MPH
72H 08/0000Z 44.4N 33.5W 65 KT 75 MPH
96H 09/0000Z 46.6N 26.0W 55 KT 65 MPH...POST-TROP/EXTRATROP
120H 10/0000Z 48.4N 17.7W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Roberts

[cycloneye]

Hurricane Danielle Discussion Number 17
NWS National Hurricane Center Miami FL AL052022
900 AM GMT Mon Sep 05 2022

There's been little change in Danielle's cloud pattern during the
past 6 hours, and a clear symmetric warm 13C banding eye feature
has persisted and has intermittently been closing off. The
satellite intensity estimates haven't changed, and the initial
intensity is held at 80 kt for this advisory.

Little change in strength is forecast through today. Afterward,
the cyclone should slowly weaken through the entire period as it
moves over cooler water while increasing southwesterly shear
disrupts the upper outflow pattern. The CMC, UKMET, and the GFS
agree with Danielle to begin an extratropical transition around 36
hours and complete its change by 72 hours (Thursday). This cyclone
transformation timeline is reflected in the NHC forecast, and the
predicted 5-day intensity closely follows the IVCN and HCCA aids.

The hurricane's initial motion is estimated to be 030 at 7 kt, a
little faster than previously noted. Danielle should continue to
accelerate and move north-northeastward to northeastward through
early Tuesday in response to a mid-latitude baroclinic system
approaching from the northwest, out of the Canadian Maritimes. By
Tuesday night, the cyclone should turn toward the east-northeast
within the mid-latitude westerly steering flow and continue in
this general motion for 60 hours. A turn back toward the northeast
is forecast as an extratropical cyclone on Thursday. It's
worth mentioning that earlier today, there was quite a bit of
uncertainty (global model cross-track spread) about Danielle's
trajectory beyond the mid-period. The GFS and the UKMET predict
Danielle will turn back toward the northeast Wednesday in the
southwesterly peripheral flow of a larger baroclinic low
approaching the cyclone from the northwest Atlantic. However, the
ECMWF 12 and 18z runs showed considerably less baroclinic low
influence while continuing toward the east-northeast, southwest of
the British Isles. The latest 00z run, subsequently, has trended
more toward the GFS/UKMET solution, which has resulted in some
increase in track forecast confidence. Accordingly, the NHC
forecast is again adjusted slightly north of the previous one to
align more with a consensus (TVCA) of the models mentioned above.


FORECAST POSITIONS AND MAX WINDS

INIT 05/0900Z 39.6N 44.4W 80 KT 90 MPH
12H 05/1800Z 40.5N 43.6W 80 KT 90 MPH
24H 06/0600Z 41.4N 42.4W 75 KT 85 MPH
36H 06/1800Z 42.1N 40.6W 75 KT 85 MPH
48H 07/0600Z 42.8N 38.3W 70 KT 80 MPH
60H 07/1800Z 43.8N 35.6W 65 KT 75 MPH
72H 08/0600Z 45.3N 32.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
96H 09/0600Z 48.2N 26.1W 55 KT 65 MPH...POST-TROP/EXTRATROP
120H 10/0600Z 50.8N 20.6W 50 KT 60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Roberts