ATL: ERIN - Advisories

[StormWeather]

BULLETIN
Tropical Storm Erin Advisory Number 1
NWS National Hurricane Center Miami FL AL052025
200 PM CVT Mon Aug 11 2025

...TROPICAL STORM ERIN FORMS JUST WEST OF THE CABO VERDE ISLANDS...


SUMMARY OF 200 PM CVT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...17.4N 28.0W
ABOUT 280 MI...455 KM WNW OF THE CABO VERDE ISLANDS
ABOUT 2305 MI...3710 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



000
WTNT45 KNHC 111447
TCDAT5

Tropical Storm Erin Discussion Number 1
NWS National Hurricane Center Miami FL AL052025
200 PM CVT Mon Aug 11 2025

The system we have been monitoring that moved across the Cabo Verde
Islands over the past 6-12 h (Invest 97L) has maintained a small,
but persistent area of deep convection. This activity prompted an
earlier TAFB subjective Dvorak fix of T2.5/35 kt suggesting the
convection is now sufficently organized to be classified as a
tropical cyclone. We also received scatterometer data at 1107 UTC
with a peak wind retrieval of 39 kt embedded in this convection,
with an ambiguity analysis suggesting the circulation is also
well defined, albeit still somewhat elongated on the eastern edge.
The combination of all this data suggests that a tropical storm has
formed, and NHC is initiating advisories on Tropical Storm Erin with
a current intensity of 40 kt.

Erin is moving quickly off to the west, with the motion estimated at
275/17 kt. Over the next few days, this motion should continue with
possibly some slight south-of-due-west motion. Erin's motion is
primarily influenced by an east-to-west oriented mid-level ridge
draped across the subtropical Atlantic basin. By the end of the
forecast period, this ridge may start to become more oriented to the
northeast of Erin, inducing a more poleward motion by 120 h. The
initial NHC track forecast elects to stick fairly close to the HFIP
corrected consensus approach (HCCA), which is a touch on the south
side of the overall track guidance envelope. It should be noted that
spread in the track guidance, especially the ensembles, begins to
increase markedly at the end of the forecast period.

The intensity forecast in the short-term is a little tricky. The
earlier scatterometer data indicate the system has a small
circulation which could be prone to rapid intensity changes, either
up or down. While vertical wind shear over the system is forecast to
be low, between 5-10 kt over the next 72 hours, sea-surface
temperatures are more marginal, around 26-27C, with a decent amount
of dry mid-level air along the path of the tropical storm. The first
NHC intensity forecast will thus only forecast slow intensification
in the short-term, assuming the marginal SSTs and lack of mid-level
moisture will keep the small vortex in check. After 48 h, however,
the SSTs start to gradually increase and should allow the local
environment of Erin to moisten up. Thus, the rate of intensification
will likely increase in the second half of the forecast period. The
NHC intensity forecast is a little on the high side of the guidance
in the short-term, partially due to the initial intensity, but is in
line with the HCCA intensity aid. By 120 h, the hurricane-regional
models (e.g., HWRF/HAFS), and statistical-dynamical aids
(EC-SHIPS/LGEM) show Erin becoming a major hurricane, and that will
be explicitly forecast at the end of the period.

FORECAST POSITIONS AND MAX WINDS

INIT 11/1500Z 17.4N 28.0W 40 KT 45 MPH
12H 12/0000Z 17.5N 31.2W 45 KT 50 MPH
24H 12/1200Z 17.4N 35.1W 50 KT 60 MPH
36H 13/0000Z 17.1N 38.7W 55 KT 65 MPH
48H 13/1200Z 17.1N 41.7W 60 KT 70 MPH
60H 14/0000Z 17.4N 45.0W 70 KT 80 MPH
72H 14/1200Z 18.0N 48.4W 80 KT 90 MPH
96H 15/1200Z 19.6N 54.0W 90 KT 105 MPH
120H 16/1200Z 21.5N 60.0W 100 KT 115 MPH

$$
Forecaster Papin

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 2
NWS National Hurricane Center Miami FL AL052025
500 PM AST Mon Aug 11 2025

...ERIN FORECAST TO BECOME A HURRICANE LATER THIS WEEK IN THE
CENTRAL TROPICAL ATLANTIC...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.4N 30.3W
ABOUT 430 MI...690 KM WNW OF THE CABO VERDE ISLANDS
ABOUT 2155 MI...3465 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Erin Discussion Number 2
NWS National Hurricane Center Miami FL AL052025
500 PM AST Mon Aug 11 2025


Erin's structure this afternoon looks like a tropical cyclone that
is struggling with the nearby thermodynamic environment, with only a
small patch of deep convection pulsing near the estimated center. It
is possible some dry air may have been entrained into the small
circulation earlier today, causing its degraded appearance. For now,
subjective and objective intensity estimates haven't changed much
from the prior advisory, hovering in the 35-42 kt range, so the
initial intensity is held at 40 kt this advisory.

Erin is still moving quickly off to the west, with the latest
estimated motion at 270/18 kt. This general motion with a gradual
slowdown in forward speed is expected over the next 48-72 h as the
system remains steered by a prominent mid-level ridge to its north.
This ridge is forecast to move along with the storm. Towards the end
of the forecast period, the ridge should erode some and shift
northeastward of Erin, which should allow the cyclone to begin
gaining latitude by 120 h. The deterministic track guidance
generally agrees on this track evolution, and was only a little
faster than the prior cycle. The NHC track forecast is quite similar
to the previous one, and lies closest to a blend of the latest 12z
GFS and ECMWF forecasts (GFEX). However, it should be noted that
spread in the ensemble solutions starts to increase substantially by
the end of the forecast period, likely related to the magnitude of
ridging that remains poleward of Erin in five days.

As mentioned in the prior advisory, while vertical wind shear over
Erin is forecast to remain low for the next 3-4 days, the
thermodynamic environment is less favorable in the short-term, with
sea-surface temperatures between 26-27C, and plenty of stable
stratocumulus clouds along the forecast path of the storm.
Nonetheless, most of the hurricane-regional models show Erin slowly
intensifying during this period. As the storm moves into warmer
sea-surface temperatures after 48 h, a faster rate of
intensification is anticipated, as long as the shear remains low and
if Eric is able to mix out some of the dry air in its vicinity. The
intensity guidance is actually a little higher than the previous
cycle beyond 60 h, but the latest NHC intensity forecast is similar
to the prior one, showing Erin becoming a hurricane in 60 h and a
major hurricane in 120 h. This forecast is now a little lower than
HAFS-A/B, HMON, and HWRF at the end of the forecast. There are some
indications there might some northwesterly shear impinging on the
cyclone in 96-120 h, so I elected to stay under these aids for this
cycle.

KEY MESSAGES:

1. It is still too early to determine what impacts, if any, Erin may
bring to the northern Leeward Islands, Bermuda, or the east coast of
the United States. As we approach the climatological peak of the
hurricane season, it is an opportune time to ensure your
preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 11/2100Z 17.4N 30.3W 40 KT 45 MPH
12H 12/0600Z 17.4N 33.4W 45 KT 50 MPH
24H 12/1800Z 17.3N 37.1W 50 KT 60 MPH
36H 13/0600Z 17.1N 40.5W 55 KT 65 MPH
48H 13/1800Z 17.3N 44.0W 60 KT 70 MPH
60H 14/0600Z 17.8N 47.0W 70 KT 80 MPH
72H 14/1800Z 18.5N 50.0W 80 KT 90 MPH
96H 15/1800Z 20.0N 55.6W 95 KT 110 MPH
120H 16/1800Z 22.0N 60.5W 100 KT 115 MPH

$$
Forecaster Papin

[AJC3]

BULLETIN
Tropical Storm Erin Advisory Number 3
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Mon Aug 11 2025

...ERIN MOVING QUICKLY WESTWARD...
...FORECAST TO BECOME A HURRICANE LATER THIS WEEK IN THE CENTRAL
TROPICAL ATLANTIC...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.6N 32.3W
ABOUT 560 MI...900 KM WNW OF THE CABO VERDE ISLANDS
ABOUT 2020 MI...3255 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 22 MPH...35 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Erin Discussion Number 3
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Mon Aug 11 2025

After struggling earlier during the diurnal convective minimum, a
large convective burst has formed and persisted over the center of
Erin for the past several hours, and a recent GPM microwave pass
from 11/2237 UTC confirmed that the low-level center is underneath
this burst. The latest subjective intensity estimates range from
35-45 kt, and the objective intensity estimates from UW-CIMSS have
crept up slightly to the 40-45 kt range. The initial intensity is
held at 40 kt, which might be a tad conservative.

Erin continues moving quickly westward, with the latest motion
estimated at 275/18 kt. This general motion with a gradual decrease
in forward speed is expected over the next 2 to 3 days as the
tropical storm is steered by a mid-level subtropical ridge to its
north. Towards the end of the forecast period, the ridge should
erode some, which would allow Erin to turn toward the west-northwest
and gain some latitude. However, there are some differences in the
global models as to how significant the weakness in the ridge will
be, and this will affect how far north the cyclone gets by day 5.
Some of the recent model solutions are a bit farther to the left (or
southwest) at the end of the forecast period. The NHC forecast is
nudged only very slightly to the left at days 4-5, and now lies
slightly to the north of the latest consensus aids. Based on the
model spread, the confidence in the track forecast appears to be
about average.

Erin is expected to remain in low vertical wind shear conditions for
the next 3-4 days. The thermodynamic environment is less favorable
in the short-term, with sea-surface temperatures (SSTs) around
26-27C, and stable stratocumulus clouds noted just to the west and
northwest of Erin. Only slow strengthening is forecast during the
next 1 to 2 days until Erin reaches warmer water. A faster rate of
intensification is anticipated after that time. The latest NHC
forecast is very similar to the previous one, and lies slightly
below the intensity consensus for the first 36 h. Thereafter, the
NHC intensity forecast is near the middle of the intensity guidance
envelope. It is possible that vertical wind shear could increase in
4 to 5 days, but that will depend on where the upper-level ridge is
situated in relation to Erin, which is uncertain at this time.

KEY MESSAGES:

1. It is still too early to determine what impacts, if any, Erin may
bring to the northern Leeward Islands, Bermuda, or the east coast of
the United States. As we approach the climatological peak of the
hurricane season, it is an opportune time to ensure your
preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 12/0300Z 17.6N 32.3W 40 KT 45 MPH
12H 12/1200Z 17.4N 35.2W 45 KT 50 MPH
24H 13/0000Z 17.2N 38.8W 50 KT 60 MPH
36H 13/1200Z 17.1N 42.2W 55 KT 65 MPH
48H 14/0000Z 17.4N 45.4W 65 KT 75 MPH
60H 14/1200Z 18.0N 48.4W 75 KT 85 MPH
72H 15/0000Z 18.7N 51.3W 85 KT 100 MPH
96H 16/0000Z 20.3N 56.8W 95 KT 110 MPH
120H 17/0000Z 21.9N 61.5W 100 KT 115 MPH

$$
Forecaster Hagen

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 4
NWS National Hurricane Center Miami FL AL052025
500 AM AST Tue Aug 12 2025

...ERIN EXPECTED TO BEGIN STRENGTHENING SOON...
...LIKELY TO BECOME A HURRICANE LATER THIS WEEK IN THE CENTRAL
TROPICAL ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...17.4N 34.3W
ABOUT 690 MI...1105 KM W OF THE CABO VERDE ISLANDS
ABOUT 1890 MI...3045 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 22 MPH...35 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Erin Discussion Number 4
NWS National Hurricane Center Miami FL AL052025
500 AM AST Tue Aug 12 2025

The storm has not become significantly better organized on
geostationary satellite imagery over the past few hours. Deep
convection has diminished in intensity, as evidenced by a warming of
the cloud tops. An AMSR microwave image from a few hours ago showed
a well-defined banding feature over the southern semicircle of the
system. Subjective Dvorak intensity estimates range from 35 to 45
kt and objective estimates from UW-CIMSS are generally near 40 kt.
Thus the advisory intensity is held at 40 kt.

Erin continues its rapid westward motion, at around 265/19 kt.
A strong 500 mb ridge is situated to the north of the cyclone,
resulting in a strong easterly steering current. The tropical
cyclone should continue on a general westward heading for the next
few days with a gradual decrease in forward speed as the ridge
weakens slightly. Later in the forecast period, the ridge is
expected to weaken a little more, and a more west-northwestward
track is likely. The official forecast track is a little left, or
south, of the previous one in 3-5 days, and very close to the
latest dynamical model consensus. This also very similar to the
mean of the GFS and ECMWF solutions. The spread of the track
models suggest near-average confidence in the NHC forecast.

During the forecast period, Erin will be traversing warmer
ocean waters and the SHIPS model diagnoses low vertical wind shear
over the system for the next several days. However, the model does
not indicate an increase in the environmental low- to
mid-tropospheric humidity during the next 72 hours or so.
Nonetheless, given the low shear and increasing SSTs, strengthening
is expected. The official intensity forecast is at the high end of
the model guidance and shows Erin becoming a major hurricane in
around 5 days. There is significant uncertainty in intensity
predictions at this time range.


KEY MESSAGES:

1. It is still too early to determine what impacts, if any, Erin may
bring to the northern Leeward Islands, Bermuda, or the east coast of
the United States. As we approach the climatological peak of the
hurricane season, this is an opportune time to ensure your
preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 12/0900Z 17.4N 34.3W 40 KT 45 MPH
12H 12/1800Z 17.2N 37.2W 45 KT 50 MPH
24H 13/0600Z 17.0N 40.5W 50 KT 60 MPH
36H 13/1800Z 17.0N 43.6W 55 KT 65 MPH
48H 14/0600Z 17.4N 46.8W 65 KT 75 MPH
60H 14/1800Z 18.0N 49.9W 75 KT 85 MPH
72H 15/0600Z 18.7N 52.7W 85 KT 100 MPH
96H 16/0600Z 20.0N 58.0W 95 KT 110 MPH
120H 17/0600Z 21.5N 62.5W 100 KT 115 MPH

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 5
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Tue Aug 12 2025

...ERIN MOVING QUICKLY WESTWARD...
...FORECAST TO BECOME A HURRICANE IN A FEW DAYS OVER THE CENTRAL
TROPICAL ATLANTIC...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.2N 36.3W
ABOUT 820 MI...1315 KM W OF THE CABO VERDE ISLANDS
ABOUT 1765 MI...2835 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


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

Interests in the northern Leeward Islands, Virgin Islands, and
Puerto Rico should monitor the progress of Erin.



Tropical Storm Erin Discussion Number 5
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Tue Aug 12 2025

Erin still has a well-defined low-level circulation, but the
convective pattern has degraded since overnight, with only a band
of moderate convection located within the southern part of the
circulation. A 1226 UTC ASCAT-C pass showed a maximum wind barb of
36 kt north of the center, and the intensity is held at a possibly
generous 40 kt. Most likely, this is a result of Erin's fast
motion, which has been south of due west (265 deg) at about 20 kt.

The guidance suite indicates that Erin may continue to lose some
latitude during the next 24 to 36 hours due to strong low- to
mid-level ridging over the eastern and central Atlantic, but overall
the general motion should be westward through early Thursday. After
that time, indications are that the ridge may weaken over the
western and central Atlantic, causing Erin to turn
west-northwestward, but there are model discrepancies on when
that might happen and where the break in the ridge actually forms.
The trend has been for a weaker Erin in the short term and possibly
a stronger ridge, and a number of track models, including HAFS-A and
-B, HWRF, the European, HCCA, and the Google Deep Mind, have shifted
south and west for much of the 5-day forecast. The NHC forecast has
shifted in that direction accordingly, and it should be noted that a
significant number of deterministic models and ensemble members
still lie even farther south.

The environment of marginal water temperatures (26-27 deg Celsius)
and low atmospheric instability and moisture appear to remain
nearly constant for the next 24 hours or so. Therefore, little to
no intensification is expected through early Wednesday. The
environment and water temperatures become much more suitable for
strengthening by 48 hours, and since the cyclone already has a
well-defined structure, it could become a hurricane by late
Thursday. Continued strengthening is forecast after that time, and
the NHC forecast continues to show Erin becoming a major hurricane
by day 5 (early Sunday). There is quite a lot of spread in the
intensity models, and the NHC prediction is in the upper regime of
the envelope, close to the SHIPS model, Florida State
Superensemble, and ICON intensity consensus.


KEY MESSAGES:

1. Although it is still too early to know exactly what impacts Erin
might bring to the northern Leeward Islands, the Virgin Islands,
and Puerto Rico, the risk has increased for Erin to move closer to
these islands over the weekend. Interests there should monitor the
progress of this storm.

2. There is even greater uncertainty in what impacts, if any, might
occur in portions of the Greater Antilles, the Bahamas, the east
coast of the United States, and Bermuda next week. As we approach
the climatological peak of the hurricane season, this is an
opportune time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 12/1500Z 17.2N 36.3W 40 KT 45 MPH
12H 13/0000Z 16.8N 39.1W 40 KT 45 MPH
24H 13/1200Z 16.5N 42.3W 40 KT 45 MPH
36H 14/0000Z 16.6N 45.2W 45 KT 50 MPH
48H 14/1200Z 17.1N 48.3W 55 KT 65 MPH
60H 15/0000Z 17.8N 51.3W 65 KT 75 MPH
72H 15/1200Z 18.5N 54.4W 75 KT 85 MPH
96H 16/1200Z 19.8N 60.3W 90 KT 105 MPH
120H 17/1200Z 21.4N 65.0W 100 KT 115 MPH

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 6
NWS National Hurricane Center Miami FL AL052025
500 PM AST Tue Aug 12 2025

...ERIN STILL MOVING QUICKLY WESTWARD...
...FORECAST TO BECOME A HURRICANE OVER THE CENTRAL TROPICAL
ATLANTIC IN A COUPLE OF DAYS...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.0N 38.3W
ABOUT 950 MI...1525 KM W OF THE CABO VERDE ISLANDS
ABOUT 1635 MI...2630 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 22 MPH...35 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES



Tropical Storm Erin Discussion Number 6
NWS National Hurricane Center Miami FL AL052025
500 PM AST Tue Aug 12 2025

Not much has changed with Erin's structure since this morning. A
little bit of convection has formed over the low-level center, but
overall the shower and thunderstorm activity remains limited. Due
to the cyclone's fast motion, it is assumed that the maximum winds
have not decreased, so the initial intensity is held at 40 kt.

A quick south-of-due-west motion is expected to continue for the
next 24 hours, with strong low- to mid-level ridging located to the
north over the central and eastern Atlantic. Global models
indicate that ridge is likely to weaken in a few days, which should
cause Erin to begin moving west-northwestward in about 60 hours,
with that motion continuing through day 5 (Sunday). In contrast to
this morning, there were no major shifts in the latest track model
simulations. The new NHC forecast has been placed along the
southern part of the guidance envelope, lying closest to the HFIP
Corrected Consensus (HCCA) and Google Deep Mind (GDM) models. This
results in the new NHC track forecast having no appreciable
difference from the morning forecast, with no additional shifting
toward the northern Leeward Islands. Keep in mind that NHC track
forecasts have an average error of 120-180 n mi (150-215 statute
miles) at days 4 and 5, and future adjustments in the forecast are
still possible.

It may still take Erin a little bit of time to produce more
significant deep convection while it continues to move over
marginally warm sea surface temperatures and through an atmosphere
of only modest instability and moisture. Sea surface temperatures
and instability begin to increase after about 24 hours, which
should allow Erin to produce more organized convection. Given that
the cyclone already has a well-defined low-level structure, this
could result in significant intensification toward the latter part
of the forecast period, especially since the global models show an
upper-level anticyclone building over the storm. The NHC intensity
forecast is near the lower end of the guidance during the first few
days of the forecast, but then falls in line closer to the
consensus aids in 3-5 days. In this scenario, Erin would still
become a major hurricane in about 4 or 5 days.


KEY MESSAGES:

1. Erin could move close enough to the northern Leeward Islands,
Virgin Islands, and Puerto Rico over the weekend to produce some
impacts on those islands. However, the magnitude of those impacts
is still not known, and interests there should continue to monitor
the progress of this storm.

2. There is even greater uncertainty in what impacts might occur in
portions of the Greater Antilles, the Bahamas, the east coast of
the United States, and Bermuda next week. As we approach the
climatological peak of the hurricane season, this is an opportune
time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 12/2100Z 17.0N 38.3W 40 KT 45 MPH
12H 13/0600Z 16.6N 40.8W 40 KT 45 MPH
24H 13/1800Z 16.4N 43.9W 45 KT 50 MPH
36H 14/0600Z 16.6N 46.8W 50 KT 60 MPH
48H 14/1800Z 17.2N 49.9W 60 KT 70 MPH
60H 15/0600Z 17.9N 52.9W 75 KT 85 MPH
72H 15/1800Z 18.6N 56.0W 85 KT 100 MPH
96H 16/1800Z 20.0N 61.5W 95 KT 110 MPH
120H 17/1800Z 22.2N 65.7W 100 KT 115 MPH

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 7
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Tue Aug 12 2025

...ERIN LIKELY TO BECOME A HURRICANE OVER THE CENTRAL TROPICAL
ATLANTIC IN A COUPLE OF DAYS...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.7N 40.1W
ABOUT 1520 MI...2440 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


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

Interests in the northern Leeward Islands, Virgin Islands, and
Puerto Rico should monitor the progress of Erin.



Tropical Storm Erin Discussion Number 7
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Tue Aug 12 2025

Deep convection has returned near Erin this evening, though it
appears to mostly be west of the center. An ASCAT pass from a few
hours ago showed maximum winds of about the same magnitude as the
earlier data, 35-40 kt, though it did display a larger area of
tropical-storm-force winds. With no significant change in the
satellite intensity estimates, the initial wind speed remains 40 kt.

The environment around Erin gradually gets more conducive for
strengthening during the next day or so, including a slow rise in
SSTs and instability. By late Thursday, SSTs rise above 28C with
continued light or moderate shear. This evolution should promote
slow intensification in the near-term, followed by quick
intensification in a couple of days, especially if Erin continues
to have a small core. The new NHC intensity forecast is similar to
the previous one, but a little higher to follow the latest
corrected consensus guidance. Beyond 96 hours, the global models
all suggest that shear will increase, so the wind speed is leveled
off at that point.

Erin continues to move quickly south-of-due-west (260/17) due
to strong low- to mid-level ridging located to the north over the
central and eastern Atlantic. Model guidance has trended a bit
southward in the near-term, so the first day or so of the forecast
has been adjusted equatorward. In a couple of days, a weakening of
that ridge is anticipated, which should cause Erin to begin moving
west-northwestward by Friday. There are no significant changes to
the long-range NHC forecast, and note that the 18Z GFS appeared to
be a significant outlier and was mostly disregarded in this package.
The new forecast remains along the southern part of the guidance
envelope, lying closest to the HFIP Corrected Consensus (HCCA) and
Google Deep Mind (GDM) models. Keep in mind that NHC track
forecasts have an average error of 120-180 n mi (150-215 statute
miles) at days 4 and 5, and future adjustments in the forecast are
still possible.


KEY MESSAGES:

1. Erin could move close enough to the northern Leeward Islands,
Virgin Islands, and Puerto Rico over the weekend to produce some
impacts on those islands. However, the magnitude of those impacts
is still not known, and interests there should continue to monitor
the progress of this storm.

2. There is even greater uncertainty in what impacts might occur in
portions of the Greater Antilles, the Bahamas, the east coast of
the United States, and Bermuda next week. As we approach the
climatological peak of the hurricane season, this is an opportune
time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 13/0300Z 16.7N 40.1W 40 KT 45 MPH
12H 13/1200Z 16.3N 42.6W 45 KT 50 MPH
24H 14/0000Z 16.2N 45.5W 45 KT 50 MPH
36H 14/1200Z 16.6N 48.4W 50 KT 60 MPH
48H 15/0000Z 17.3N 51.4W 60 KT 70 MPH
60H 15/1200Z 18.1N 54.6W 75 KT 85 MPH
72H 16/0000Z 18.9N 57.5W 85 KT 100 MPH
96H 17/0000Z 20.5N 62.6W 100 KT 115 MPH
120H 18/0000Z 22.5N 66.5W 100 KT 115 MPH

$$
Forecaster Blake

[cycloneye]

Tropical Storm Erin Discussion Number 8
NWS National Hurricane Center Miami FL AL052025
500 AM AST Wed Aug 13 2025

Deep convection is redeveloping intermittently over the western
portion of Erin's circulation. However the system continues to
have a rather ragged-looking appearance, with limited convective
banding features. There appears to be some easterly shear over the
storm at this time. Subjective Dvorak classifications are a little
below tropical storm strength and objective intensity estimates
from UW-CIMSS are generally in the 35-40 kt range. Based on these
estimates, the advisory intensity remains at 40 kt.

Erin has not been able to strengthen significantly for the past
couple of days, likely due to marginal SSTs, and a relatively dry
mid- to lower-tropospheric air mass. However, it is expected that
the system's environment will gradually become more conducive for
intensification over the next 48 hours. In particular, Erin will
be traversing progressively warmer ocean waters with likely a
little less environmental subsidence. The official intensity
forecast is similar to the previous ones and continues to call for
Erin to become a hurricane later this week. This is also supported
by the corrected model consensus, HCCA, and Google DeepMind model
guidance.

Although the center is not easy to locate, it is estimated that the
cyclone is continuing on its generally westward track, at about
260/17 kt. A strong low- to mid-level ridge is situated to the
north of Erin, and in a few days a slight weakness develops in the
ridge near 65W longitude. This should cause the tropical cyclone to
begin to move west-northwestward at a slightly slower forward speed
in a couple of days. The track guidance is in fairly good
agreement, and the official forecast is close to the HCCA solution
and is on the southern side of the model track forecast suite. This
is also very similar to the previous NHC prediction. Users are
reminded that NHC track forecasts have an average error of 120-180 n
mi (150-215 statute miles) at days 4 and 5, and future adjustments
to the forecast are still possible.


KEY MESSAGES:

1. Erin could move close enough to the northern Leeward Islands, the
Virgin Islands, and Puerto Rico over the weekend to produce some
impacts on those islands. However, the magnitude of those impacts
is still not known, and interests there should continue to monitor
the progress of this storm.

2. There is even greater uncertainty in what impacts might occur in
portions of the Greater Antilles, the Bahamas, the east coast of
the United States, and Bermuda next week. As we approach the
climatological peak of the hurricane season, this is an opportune
time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 13/0900Z 16.5N 41.9W 40 KT 45 MPH
12H 13/1800Z 16.4N 44.1W 45 KT 50 MPH
24H 14/0600Z 16.5N 47.1W 50 KT 60 MPH
36H 14/1800Z 17.0N 50.0W 55 KT 65 MPH
48H 15/0600Z 17.8N 52.9W 65 KT 75 MPH
60H 15/1800Z 18.6N 55.8W 75 KT 85 MPH
72H 16/0600Z 19.5N 58.7W 85 KT 100 MPH
96H 17/0600Z 21.3N 63.5W 100 KT 115 MPH
120H 18/0600Z 23.4N 66.8W 100 KT 115 MPH

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 9
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Wed Aug 13 2025

...ERIN CONTINUES GENERALLY WESTWARD...
...EXPECTED TO BECOME A HURRICANE IN A COUPLE OF DAYS...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.3N 43.4W
ABOUT 1305 MI...2100 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


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

Interests in the northern Leeward Islands, Virgin Islands, and
Puerto Rico should monitor the progress of Erin.



Tropical Storm Erin Discussion Number 9
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Wed Aug 13 2025

Erin continues to have a ragged overall appearance, with one burst
of convection just southwest of the center and skeletal convective
bands elsewhere in the northwestern semicircle. Various subjective
and objective satellite intensity estimates are in the 30-45 kt
range, and these have changed little over the past several hours.
A just-received scatterometer overpass shows winds near 40 kt just
north of the center, and based on these data the initial intensity
is held at 40 kt.

Erin continues to struggle to intensify, likely due to its track
over persistent sea surface temperatures of 26-27C and entrainment
of dry and stable air. The forecast track keeps the system over
these marginal SSTs for another 24 h or so, followed by a motion
over increasing SSTs that reach 29-30C by the end of the forecast
period. The cyclone is currently in a favorable low- to
moderate-shear environment, and this is likely to continue for the
next 72 h. This evolution should allow Erin to significantly
intensify, with the cyclone forecast to become a hurricane by 48 h
and a major hurricane by 96 hr. After 72-96 h, Erin may encounter
increased northerly shear as it tracks to the northeast of a
large upper-level anticyclone forecast to form near Hispaniola and
the southeastern Bahamas. Although the strength of shear the cyclone
will encounter is uncertain, the intensity guidance suggests a lower
rate of intensification at that time. The new intensity forecast is
little changed from the previous forecast and is in best agreement
with the intensity consensus.

The initial motion is now 265/15 kt. While a strong low- to
mid-level ridge currently is situated to the north of Erin, in a day
or two a slight weakness is forecast to develop in this ridge near
65W longitude. This should cause the tropical cyclone to turn
west-northwestward after 24 h, with some decrease in forward speed
after 72 h. After 96 h, a developing break in the ridge near the
southeastern coast of the United States should lead to a
northwestward motion. The track guidance is in fairly good
agreement, and the official forecast on the southern side of the
guidance envelope between the HCCA corrected consensus and the other
consensus models. The new track is similar to the previous track
through 72 h and a little west of the previous track thereafter.
Users are reminded that NHC track forecasts have an average error of
150 to 215 miles at days 4 and 5, and future adjustments to the
forecast are still possible.


KEY MESSAGES:

1. Erin could move close enough to the northern Leeward Islands, the
Virgin Islands, and Puerto Rico over the weekend to produce some
impacts on those islands. However, the magnitude of those impacts
is still not known, and interests there should continue to monitor
the progress of this storm.

2. There is even greater uncertainty in what impacts might occur in
portions of the Greater Antilles, the Bahamas, the east coast of
the United States, and Bermuda next week. As we approach the
climatological peak of the hurricane season, this is an opportune
time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 13/1500Z 16.3N 43.4W 40 KT 45 MPH
12H 14/0000Z 16.3N 45.6W 45 KT 50 MPH
24H 14/1200Z 16.6N 48.6W 50 KT 60 MPH
36H 15/0000Z 17.4N 51.5W 55 KT 65 MPH
48H 15/1200Z 18.2N 54.3W 65 KT 75 MPH
60H 16/0000Z 19.0N 57.2W 75 KT 85 MPH
72H 16/1200Z 19.9N 60.0W 85 KT 100 MPH
96H 17/1200Z 21.7N 64.6W 100 KT 115 MPH
120H 18/1200Z 23.9N 67.3W 105 KT 120 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 10
NWS National Hurricane Center Miami FL AL052025
500 PM AST Wed Aug 13 2025

...ERIN STRENGTHENS AS IT MOVES WESTWARD...
...EXPECTED TO BECOME A HURRICANE IN A DAY OR TWO...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...16.3N 45.0W
ABOUT 1200 MI...1930 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES



Tropical Storm Erin Discussion Number 10
NWS National Hurricane Center Miami FL AL052025
500 PM AST Wed Aug 13 2025

Convection has become more concentrated near the center of Erin
during the past few hours, although the storm still has a somewhat
ragged overall appearance. Satellite intensity estimates have
increased a little since the last advisory and are now in the 35-50
kt range. Based on these trends, the initial intensity is increased
to 45 kt.

Erin remains in an area of marginal sea surface temperatures and
moisture and this should continue for another 12 h or so. After
that, the forecast track takes the system over warmer SSTs that
increase to 29-30C by the end of the forecast period. In addition,
the cyclone is currently in a favorable low- to moderate-shear
environment, and this is likely to continue for the next 72 h or so.
This evolution should allow Erin to significantly intensify, with
the cyclone forecast to become a hurricane by 36 h and a major
hurricane by 96 hr. After 72-96 h, Erin may encounter increased
northwesterly shear as it tracks to the northeast of a large
upper-level anticyclone forecast to form near Hispaniola and the
southeastern Bahamas. Although it is unclear how much shear Erin
will encounter, the intensity guidance suggests at least a lower
rate of intensification at that time. The new intensity forecast is
adjusted upward somewhat from the previous forecast through 72 h
based on current trends and the intensity consensus.

The initial motion is now 270/15 kt. A low- to mid-level ridge
north of Erin should steer the cyclone westward for the next 12 h
or so, followed by a generally west-northwestward motion through
96 h. After that time, a developing break in the ridge near the
southeastern coast of the United States should lead to a
northwestward motion. The track guidance is still in fairly good
agreement, and the official forecast remains on the southern side
of the guidance envelope between the HCCA corrected consensus and
the other consensus models. However, the guidance envelope has
shifted a little westward since the last advisory, and the new
forecast track is also a little west of the previous track. Users
are reminded that NHC track forecasts have an average error of
150 to 215 miles at days 4 and 5, and future adjustments to the
forecast are still possible.

It should be noted that the directional spread becomes very large
in both the deterministic and ensemble track guidance at long range.
Therefore, there is a greater than normal uncertainty about what
impacts Erin may bring to portions of the Bahamas, the east coast
of the United States, and Bermuda.


KEY MESSAGES:

1. Locally heavy rainfall, high surf and rip currents, and
tropical-storm force winds could occur in portions of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend as
the core of Erin passes north of those islands. Interests in these
areas should continue to monitor the progress of Erin.

2. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week is increasing. As we
approach the climatological peak of the hurricane season, this is an
opportune time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 16.3N 45.0W 45 KT 50 MPH
12H 14/0600Z 16.3N 47.2W 50 KT 60 MPH
24H 14/1800Z 16.9N 50.1W 55 KT 65 MPH
36H 15/0600Z 17.6N 53.0W 65 KT 75 MPH
48H 15/1800Z 18.4N 55.9W 75 KT 85 MPH
60H 16/0600Z 19.3N 58.8W 85 KT 100 MPH
72H 16/1800Z 20.2N 61.4W 95 KT 110 MPH
96H 17/1800Z 22.2N 65.8W 100 KT 115 MPH
120H 18/1800Z 24.8N 68.2W 105 KT 120 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 11
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Wed Aug 13 2025

...ERIN FORECAST TO BECOME A HURRICANE BY FRIDAY...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.3N 46.6W
ABOUT 1095 MI...1765 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES



Tropical Storm Erin Discussion Number 11
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Wed Aug 13 2025

Satellite images show that a solid area of convection remains near
Erin, with low-cloud motions suggesting the center is on the
northeastern side of the thunderstorm activity. Overall, there
hasn't been a lot of change with the satellite presentation, and
that is reflected in recent stable Dvorak and scatterometer
values. The initial intensity is held at 45 kt for this advisory.

The environment around Erin should remain marginally conducive
during the next day or so, which will likely promote gradual
strengthening. Thereafter, the storm is forecast to move across
warmer waters, with potentially a decrease in shear. This
evolution results in a period of potential rapid intensification
late this week, and the official forecast reflects that
possibility. While shear is generally forecast to increase over
the weekend, this appears to be canceled out by large-scale
divergence and water temperatures above 29C. Most models respond
to this by showing a lower rate of intensification at that time.
The new intensity forecast is adjusted upward somewhat from the
previous forecast beyond 24 h based on the current guidance.
There is increasing confidence on a large and powerful hurricane
over the southwestern Atlantic Ocean this weekend.

The initial motion is now 270/14 kt. There are no significant
changes to the forecast track or steering. Erin should move
westward overnight and then west-northwestward from Thursday through
the weekend due to steering from the subtropical ridge. The ridge
is forecast to break by early next week, resulting in a turn towards
the northwest or north-northwest. The new forecast is basically an
update of the previous forecast in the near term, and on the eastern
side of the guidance envelope by day 5 between the consensus and the
Google Deep Mind model. There is still a greater than normal
uncertainty about what impacts Erin may bring to portions of the
Bahamas, the east coast of the United States, and Bermuda in the
long range.


KEY MESSAGES:

1. Locally heavy rainfall, high surf and rip currents, and
tropical-storm force winds could occur in portions of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend as
the core of Erin passes north of those islands. Interests in these
areas should continue to monitor the progress of Erin.

2. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week is increasing. As we
approach the climatological peak of the hurricane season, this is an
opportune time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 14/0300Z 16.3N 46.6W 45 KT 50 MPH
12H 14/1200Z 16.5N 48.8W 50 KT 60 MPH
24H 15/0000Z 17.2N 51.8W 55 KT 65 MPH
36H 15/1200Z 18.0N 54.9W 70 KT 80 MPH
48H 16/0000Z 18.9N 57.8W 85 KT 100 MPH
60H 16/1200Z 19.8N 60.6W 95 KT 110 MPH
72H 17/0000Z 20.6N 62.9W 100 KT 115 MPH
96H 18/0000Z 22.8N 66.6W 105 KT 120 MPH
120H 19/0000Z 25.5N 68.5W 110 KT 125 MPH

$$
Forecaster Blake

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 12
NWS National Hurricane Center Miami FL AL052025
500 AM AST Thu Aug 14 2025

...ERIN CONTINUES WESTWARD...
...FORECAST TO BECOME A HURRICANE BY FRIDAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...16.3N 48.2W
ABOUT 990 MI...1595 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES





Tropical Storm Erin Discussion Number 12
NWS National Hurricane Center Miami FL AL052025
500 AM AST Thu Aug 14 2025

Satellite imagery shows that Erin continues to produce an area of
deep convection, with the center estimated to be on the northeastern
side of the convective shield. There has not been much change since
the previous advisory, and there has been no recent microwave
imagery to assess the overall structure. However, TAFB noted a
slight increase in the curved banding with the latest data-t
value. Subjective satellite current intensity estimates have held
steady around 45 kt, and objective satellite estimates from UW-CIMSS
range from 39 to 51 knots, with a satellite consensus of 46 kt.
Using a blend of these estimates, the intensity is held at 45 kt for
this advisory.

The overall environment around Erin is conducive for gradual
strengthening during the next day or so. Thereafter, the system is
forecast to move across warmer waters, and the GFS and EC SHIPS
guidance suggests a slight decrease in shear. This increasingly
favorable environment could result in a period of rapid
intensification, which is explicitly forecast between 24-48 h. Wind
shear may slightly increase later this weekend, although sea surface
temperatures remain around 29C, with favorable divergence aloft.
Most of the intensity guidance continues to show strengthening at
this time frame just at a steady rate, with Erin forecast to become
a major hurricane by day 3. The NHC intensity forecast is similar to
the previous and lies closest to the HCCA corrected consensus, there
are some models, such as the FSSE, that depict a higher intensity by
the end of the forecast period than the current NHC forecast. There
continues to be confidence that Erin will be a large and powerful
hurricane over the southwestern Atlantic Ocean this weekend.

Erin continues to move westward at an estimated motion of 270/15 kt.
The storm is being steered by a subtropical ridge to the north,
and the system should gradually turn more west-northwestward later
tonight, with this motion anticipated into the weekend. A weakness
in the ridge is forecast to develop early next week, resulting in a
turn towards the northwest or north-northwest. The guidance is
fairly tightly cluster through day 3, with some slight along-track
spread on the turn toward the northwest. Beyond day 3, the GFS and
Google DeepMind are on the eastern edge of the guidance, and the
hurricane regional models on the western side. The latest NHC
forecast is similar to the previous and lies near the consensus
aids. There is still a greater than normal uncertainty about what
impacts Erin may bring to portions of the Bahamas, the east coast of
the United States, and Bermuda in the long range.

KEY MESSAGES:

1. Locally heavy rainfall, high surf and rip currents, and
tropical-storm force winds could occur in portions of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend as
the core of Erin passes north of those islands. Interests in these
areas should continue to monitor the progress of Erin.

2. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week is increasing. As we
approach the climatological peak of the hurricane season, this is an
opportune time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 14/0900Z 16.3N 48.2W 45 KT 50 MPH
12H 14/1800Z 16.8N 50.5W 50 KT 60 MPH
24H 15/0600Z 17.6N 53.5W 55 KT 65 MPH
36H 15/1800Z 18.5N 56.5W 70 KT 80 MPH
48H 16/0600Z 19.3N 59.4W 85 KT 100 MPH
60H 16/1800Z 20.1N 62.0W 95 KT 110 MPH
72H 17/0600Z 21.0N 64.1W 100 KT 115 MPH
96H 18/0600Z 23.2N 67.3W 105 KT 120 MPH
120H 19/0600Z 26.0N 69.3W 110 KT 125 MPH

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 13
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Thu Aug 14 2025

...ERIN STRENGTHENING WHILE MOVING WESTWARD...
...FORECAST TO BECOME A HURRICANE BY TOMORROW...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.4N 49.7W
ABOUT 890 MI...1435 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES





Tropical Storm Erin Discussion Number 13
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Thu Aug 14 2025

Satellite imagery shows that Erin has become a little better
organized this morning, with the formation of a ragged central
dense overcast with some outer banding in the northwestern
semicircle. Satellite intensity estimates have increased a little
during the past 6 h and are now in the 40-55 kt range. Based on
these data, the initial intensity is increased to 50 kt.

Erin will be in an environment of light-to-moderate easterly
vertical shear and moving over increasing sea surface temperatures
during the next 48 h. This should allow a faster rate of
intensification during this time, and Erin is now forecast to become
a hurricane by 24 h. The environment becomes less conducive after 48
h, with the global models forecast northwesterly shear over the
cyclone as a large upper-level anticyclone develops to the west.
Despite this forecast shear, the global and regional hurricane
models forecast intensification to continue, although at a slower
rate than during the first 48 h. Based on these forecasts, the new
intensity forecast shows steady intensification through 48 h,
followed by a slower rate of development during the remainder of the
forecast period. The new forecast is near the intensity consensus,
and there is guidance that suggests the possibility Erin could be
stronger than currently forecast.

The initial motion is now 275/15. The storm continues to be steered
by a subtropical ridge to the north, and this ridge should steer the
cyclone generally west-northwestward during the next three days.
After that time, the western portion of the ridge is forecast to
weaken or break due to the influence of the mid-latitude westerlies
over the northeastern United States. This evolution should lead to
Erin turning toward the northwest or north-northwest during the
remainder of the forecast period, although there is significant
spread in the guidance on just how sharp this turn will be. The new
forecast track is south of the consensus models through 48 h and
then lies near the consensus models thereafter. Due to the spread in
the track guidance by 120 h and beyond, there is still a greater
than normal uncertainty about what impacts Erin may bring to
portions of the Bahamas, the east coast of the United States, and
Bermuda in the long range.

KEY MESSAGES:

1. Locally heavy rainfall, high surf and rip currents, and
tropical-storm force winds could occur in portions of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend as
the core of Erin passes north of those islands. Interests in these
areas should continue to monitor the progress of Erin.

2. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week is increasing. As we
approach the climatological peak of the hurricane season, this is an
opportune time to ensure your preparedness plans are in place.


FORECAST POSITIONS AND MAX WINDS

INIT 14/1500Z 16.4N 49.7W 50 KT 60 MPH
12H 15/0000Z 16.9N 51.9W 55 KT 65 MPH
24H 15/1200Z 17.8N 55.0W 65 KT 75 MPH
36H 16/0000Z 18.6N 57.9W 80 KT 90 MPH
48H 16/1200Z 19.4N 60.7W 90 KT 105 MPH
60H 17/0000Z 20.3N 63.1W 95 KT 110 MPH
72H 17/1200Z 21.3N 65.1W 100 KT 115 MPH
96H 18/1200Z 23.5N 68.0W 105 KT 120 MPH
120H 19/1200Z 26.5N 69.8W 110 KT 125 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 14
NWS National Hurricane Center Miami FL AL052025
500 PM AST Thu Aug 14 2025

...TROPICAL STORM WATCHES ISSUED FOR PORTIONS OF THE NORTHERN
LEEWARD ISLANDS...
...ERIN IS FORECAST TO BECOME A HURRICANE BY TOMORROW...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...16.7N 51.2W
ABOUT 790 MI...1270 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Meteorological Service of Antigua/Barbuda has issued a Tropical
Storm Watch for Anguilla and Barbuda.

The Meteorological Service of France has issued a Tropical Storm
Watch for St. Martin and St. Barthelemy.

The Meteorological Service of the Netherlands has issued a Tropical
Storm Watch for Saba and St. Eustatius.

The Meteorological Service of St. Maarten has issued a Tropical
Storm Watch for Sint Maarten.



Tropical Storm Erin Discussion Number 14
NWS National Hurricane Center Miami FL AL052025
500 PM AST Thu Aug 14 2025

Erin has changed little in organization during the past several
hours. Conventional satellite imagery shows that the storm
continues to produce strong convection near the center. However, a
recently received AMSR2 overpass shows that the convection is
confined mainly to the southwestern quadrant and lacks well-defined
banding. Satellite intensity estimates are now in the 45-55 kt
range, and the initial intensity remains 50 kt for this advisory.
A NOAA Hurricane Hunter aircraft is en route investigate the
system this evening, providing information on the storm's strength
and structure.

There is little change to either the intensity philosophy or
forecast since the last advisory. Erin will be in an environment of
light-to-moderate easterly vertical shear and moving over increasing
sea surface temperatures during the next 48 h. These conditions
should allow a faster rate of intensification during this time, and
Erin is still forecast to become a hurricane by 24 h. The
environment becomes less conducive after 48 h, with the global
models forecasting northwesterly shear over the cyclone as a large
upper-level anticyclone develops to the west. Despite this forecast
shear, the global and regional hurricane models forecast
intensification to continue, although at a slower rate than during
the first 48 h. Based on these forecasts, the new intensity forecast
shows steady intensification through 48 h, followed by a slower rate
of development during the remainder of the forecast period. The new
forecast is an update of the previous forecast. It should be noted
that there is some guidance that suggests a possibility Erin could
intensify further than shown in the official forecast.

The initial motion is now 280/15 kt. The storm continues to be
steered by a subtropical ridge to the north, and this ridge should
steer the cyclone generally west-northwestward during the next three
days. After that time, the western portion of the ridge is forecast
to weaken or break due to the influence of the mid-latitude
westerlies over the northeastern United States. This evolution
should lead to Erin turning toward the northwest or north-northwest
during the remainder of the forecast period, although there remains
significant spread in the guidance on just how sharp this turn will
be. The new forecast track is a little south of the previous track
through 72 h, and then it is nudged a little to the west of the
previous track at 96 and 120 h. Due to the spread in the track
guidance later in the forecast period, there is still a greater
than normal uncertainty about what impacts Erin may bring to
portions of the Bahamas, the east coast of the United States, and
Bermuda in the long range.


KEY MESSAGES:

1. Heavy rainfall across the northernmost Leeward Islands, the U.S.
and British Virgin Islands, as well as southern and eastern Puerto
Rico, may lead to isolated flash and urban flooding, along with
landslides or mudslides this weekend into early next week.

2. Tropical storm conditions are possible for portions of the
northern Leeward Islands, where Tropical Storm Watches are in
effect, beginning on Saturday as the core of Erin passes north of
those islands. Tropical storm conditions could also occur in
portions of the Virgin Islands and Puerto Rico later in the weekend,
and additional watches may be required tonight or on Friday.

3. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week is increasing.

FORECAST POSITIONS AND MAX WINDS

INIT 14/2100Z 16.7N 51.2W 50 KT 60 MPH
12H 15/0600Z 17.3N 53.5W 55 KT 65 MPH
24H 15/1800Z 18.1N 56.6W 65 KT 75 MPH
36H 16/0600Z 19.0N 59.5W 80 KT 90 MPH
48H 16/1800Z 19.8N 62.2W 90 KT 105 MPH
60H 17/0600Z 20.8N 64.4W 95 KT 110 MPH
72H 17/1800Z 21.7N 66.1W 100 KT 115 MPH
96H 18/1800Z 24.2N 68.9W 105 KT 120 MPH
120H 19/1800Z 27.2N 70.3W 110 KT 125 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Erin Intermediate Advisory Number 14A
NWS National Hurricane Center Miami FL AL052025
800 PM AST Thu Aug 14 2025

...NOAA AIRCRAFT DATA INDICATES THAT ERIN IS NEAR HURRICANE
STRENGTH...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...16.9N 51.9W
ABOUT 745 MI...1195 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for...
* Anguilla and Barbuda
* St. Martin and St. Barthelemy
* Saba and St. Eustatius
* Sint Maarten

[StormWeather]

450
WTNT35 KNHC 150247
TCPAT5

BULLETIN
Tropical Storm Erin Advisory Number 15
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Thu Aug 14 2025

...ERIN FORECAST TO BECOME A LARGE AND FORMIDABLE MAJOR
HURRICANE THIS WEEKEND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.1N 52.7W
ABOUT 690 MI...1110 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES



Tropical Storm Erin Discussion Number 15
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Thu Aug 14 2025

Erin has intensified tonight. The first NOAA-P3 reconnaissance
mission into the storm found that the center was a little more
embedded in the deep convection than earlier with a compact wind
field particularly strong on the eastern flank. Tail Doppler Radar
data from the aircraft indicated the center is starting to become
better aligned, though some residual southward tilt with height
still exists, which can also be seen on a 2339 UTC GMI microwave
pass. In the most recent leg, peak 700-mb flight level winds from
the NOAA aircraft were 69 kt in the northeast quadrant. This
value reduces to surface wind near 60 kt, just shy of
hurricane intensity.

Erin is now starting to move west-northwestward at 285/15 kt. An
extensive mid-level ridge stretched from off the eastern United
States coast all the way to the eastern Atlantic remains in place
helping to steer the storm generally west-northwestward for at least
the next 2 to 3 days with it gradually slowing down. During this
time-span, a mid-latitude trough moving into the northwestern
Atlantic is expected to dig equatorward to the northeast of Bermuda,
with another reinforcing shortwave moving into Atlantic Canada
towards the end of the forecast period. These features should create
a weakness in the subtropical ridge that Erin is expected to turn
northwestward and north-northwestward into. The latest track
guidance was quite similar to the prior cycle, just a little faster
than before towards the end of the forecast period, and only small
adjustments were made to the NHC forecast track. This track roughly
splits the latest forecast from the Google Deep Mind (GDMI) and HCCA
consensus aid. Still, there is a healthy amount of spread in the
guidance and uncertainty remains about what impacts Erin may bring
to portions of the Bahamas, the east coast of the United States, and
Bermuda in the long range.

With Erin's core structure improving this evening, the storm appears
poised to intensify more quickly in the short term. Rapid
intensification probabilities have increased in SHIPS guidance, with
now a 38-40 percent chance of a 30 kt increase in the next 24 h. The
environment continues to become more thermodynamically favorable,
with Erin crossing into 28C and warmer sea-surface temperatures, and
mid-level moisture increasing over the forecast time period. Thus,
the NHC intensity forecast will show more intensification over the
next 48-60 hours, and Erin is now forecast to become a major
hurricane earlier and peak at 115 kt, category 4 intensity. After
that time, there remains evidence in both SHIPS guidance and model
fields that northwesterly vertical wind shear could increase over
the system. In addition, there is a good chance Erin may begin to
undergo inner-core structural changes, like eyewall replacement
cycles, that could broaden its wind field but also cause its
intensity to plateau. Thus, the NHC intensity forecast now shows
some gradual weakening after a peak intensity in 72 h, though the
models show the wind radii expanding quite dramatically in the day
3-5 period. The latest NHC intensity forecast is a little on the
high side of the guidance, especially in the short-term, but ends up
near the consensus aids HCCA and IVCN towards the end of the
forecast period.

KEY MESSAGES:

1. Heavy rainfall across the northernmost Leeward Islands, the U.S.
and British Virgin Islands, as well as southern and eastern Puerto
Rico, may lead to isolated flash and urban flooding, along with
landslides or mudslides this weekend into early next week.

2. Tropical storm conditions are possible for portions of the
northern Leeward Islands, where Tropical Storm Watches are in
effect, beginning on Saturday as the core of Erin passes north of
those islands. Tropical storm conditions could also occur in
portions of the Virgin Islands and Puerto Rico later in the weekend,
and additional watches may be required tonight or on Friday.

3. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week continues to increase.


FORECAST POSITIONS AND MAX WINDS

INIT 15/0300Z 17.1N 52.7W 60 KT 70 MPH
12H 15/1200Z 17.8N 55.2W 70 KT 80 MPH
24H 16/0000Z 18.6N 58.3W 80 KT 90 MPH
36H 16/1200Z 19.4N 61.0W 90 KT 105 MPH
48H 17/0000Z 20.3N 63.3W 100 KT 115 MPH
60H 17/1200Z 21.3N 65.4W 110 KT 125 MPH
72H 18/0000Z 22.4N 67.0W 115 KT 130 MPH
96H 19/0000Z 25.0N 69.4W 110 KT 125 MPH
120H 20/0000Z 28.0N 70.4W 105 KT 120 MPH

$$
Forecaster Papin

[cycloneye]

BULLETIN
Tropical Storm Erin Intermediate Advisory Number 15A
NWS National Hurricane Center Miami FL AL052025
200 AM AST Fri Aug 15 2025

...ERIN FORECAST TO BECOME A HURRICANE TODAY...


SUMMARY OF 200 AM AST...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...17.3N 53.0W
ABOUT 665 MI...1075 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES

[cycloneye]

BULLETIN
Tropical Storm Erin Advisory Number 16
NWS National Hurricane Center Miami FL AL052025
500 AM AST Fri Aug 15 2025

...ERIN FORECAST TO STRENGTHEN INTO A HURRICANE TODAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...17.8N 54.4W
ABOUT 570 MI...920 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES



Tropical Storm Erin Discussion Number 16
NWS National Hurricane Center Miami FL AL052025
500 AM AST Fri Aug 15 2025

Erin has struggled to become better organized tonight, as the system
is still trying to establish an inner core. Convection has
diminished over the low-level center in recent hours due to some dry
air entrainment. The Air Force Reserve Hurricane Hunters have been
investigating the system this morning and found maximum flight-level
winds of 52 kt. Recent infrared satellite imagery depicts a deep
convective band becoming established in the southern semi-circle
although flight-level aircraft data found little wind within that
band. Objective satellite intensity estimates range from 55 to 67
kt. Given the latest recon data and satellite estimates, the
intensity is held at a potentially generous 60 kt. A NOAA P-3
hurricane hunter aircraft is en route to investigate the system, and
hopefully Tail Doppler Radar data will be able to better assess the
structure of the system.

Erin is moving west-northwestward at an estimated motion of 285/15
kt. A subtropical ridge to the north will continue to steer the
system west-northwestward into the weekend. A weakness in the ridge
is forecast to develop early next week, and this will result in the
system gradually turning northwestward then northward by the end of
the forecast period. The guidance is in fairly good agreement
through about 60-72 hours. After 72 hours, there are some
differences in the forward speed and cross-track spread with the
turn toward the north. The regional hurricane models lie along the
western edge of the guidance envelope with the GFS and Google
DeepMind models remaining on the eastern edge of the guidance. The
latest NHC forecast is similar to the previous one in the short
term, and was nudged slightly west beyond day 3 closer to some of
the simple consensus aids. There is still uncertainty about what
impacts Erin may bring to portions of the Bahamas, the east coast of
the United States, and Bermuda in the long range.

The storm is in a favorable environment for strengthening, and it
will likely intensify once the inner core becomes more organized.
Sea surface temperatures have warmed to about 28C and should
continue to warm to near 30C along the forecast track, with a slight
decrease in shear expected over the next day or so. Although SHIPS
guidance depicts a slight increase in shear later this weekend, the
upper-level wind pattern becomes a little more favorable with
increasing mid-level RH values. The NHC forecast is similar to the
previous with a steady rate of strengthening and lies near the
consensus aids, with Erin forecast to become a hurricane later
today, and a major hurricane late this weekend. Some of the
hurricane regional models and the Florida State Superensemble depict
a higher peak intensity than the current NHC forecast. Regardless of
the details, Erin will be a large and powerful hurricane over the
southwestern Atlantic Ocean this weekend.

KEY MESSAGES:

1. Heavy rainfall across the northernmost Leeward Islands, the U.S.
and British Virgin Islands, as well as southern and eastern Puerto
Rico, may lead to isolated flash and urban flooding, along with
landslides or mudslides this weekend into early next week.

2. Tropical storm conditions are possible for portions of the
northern Leeward Islands, where Tropical Storm Watches are in
effect, beginning on Saturday as the core of Erin passes north of
those islands. Tropical storm conditions could also occur in
portions of the Virgin Islands and Puerto Rico later in the weekend,
and additional watches may be required later today.

3. While there is still uncertainty in what impacts might occur in
portions of the Bahamas, the east coast of the United States, and
Bermuda next week, the risk of dangerous surf and rip currents
across the western Atlantic basin next week continues to increase.


FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 17.8N 54.4W 60 KT 70 MPH
12H 15/1800Z 18.4N 56.9W 70 KT 80 MPH
24H 16/0600Z 19.3N 59.9W 80 KT 90 MPH
36H 16/1800Z 20.1N 62.5W 90 KT 105 MPH
48H 17/0600Z 21.0N 64.8W 100 KT 115 MPH
60H 17/1800Z 22.2N 66.9W 110 KT 125 MPH
72H 18/0600Z 23.2N 68.5W 115 KT 130 MPH
96H 19/0600Z 25.5N 70.5W 110 KT 125 MPH
120H 20/0600Z 28.9N 71.4W 105 KT 120 MPH

$$
Forecaster Kelly

[abajan]

Tropical Storm Erin Intermediate Advisory Number 16A
NWS National Hurricane Center Miami FL AL052025
800 AM AST Fri Aug 15 2025

...ERIN BECOMING BETTER ORGANIZED AND IS EXPECTED TO BECOME A
HURRICANE LATER TODAY...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...18.1N 55.2W
ABOUT 520 MI...835 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for...
* Anguilla and Barbuda
* St. Martin and St. Barthelemy
* Saba and St. Eustatius
* Sint Maarten

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in the northern Leeward Islands, Virgin Islands,
and Puerto Rico should monitor the progress of Erin.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 AM AST (1200 UTC), the center of Tropical Storm Erin was
located near latitude 18.1 North, longitude 55.2 West. Erin is
moving toward the west-northwest near 17 mph (28 km/h). This motion
is expected to continue into the weekend. On the forecast track, the
center of Erin is likely to move near or just north of the northern
Leeward Islands over the weekend.

Maximum sustained winds are near 70 mph (110 km/h) with higher
gusts. Steady strengthening is expected during the next few days
and Erin is forecast to become a hurricane later today, and it could
become a major hurricane by this weekend.

Tropical-storm-force winds extend outward up to 90 miles (150 km)
mainly to the northeast of the center.

The latest minimum central pressure estimated from NOAA Hurricane
Hunter aircraft data is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Erin can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC.

RAINFALL: Tropical Storm Erin is expected to produce areas of heavy
rainfall beginning late Friday and continuing through the weekend
across the northernmost Leeward Islands, the U.S. and British Virgin
Islands, as well as southern and eastern Puerto Rico. Rainfall
totals of 2 to 4 inches, with isolated totals of 6 inches, are
expected. This rainfall may lead to isolated flash and urban
flooding, along with landslides or mudslides.

For a complete depiction of forecast rainfall and flash flooding
associated with Tropical Storm Erin, please see the National Weather
Service Storm Total Rainfall Graphic, available at
hurricanes.gov/graphics_at5.shtml?rainqpf

WIND: Tropical storm conditions are possible within the watch
area by early Saturday.

SURF: Swells generated by Erin will begin affecting portions of the
northern Leeward Islands, the Virgin Islands and Puerto Rico by this
weekend, and will likely spread to the western Atlantic next
week. These swells are likely to cause life-threatening surf and
rip current conditions. Please consult products from your local
weather forecast office.

A depiction of rip current risk for the United States can be found
at: hurricanes.gov/graphics_at5.shtml?ripCurrents


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

$$
Forecaster Beven

[cycloneye]

BULLETIN
Hurricane Erin Advisory Number 17
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Fri Aug 15 2025

...ERIN BECOMES THE FIRST HURRICANE OF THE 2025 SEASON...
...EXPECTED TO PASS NEAR OR NORTH OF THE LEEWARD ISLANDS ON
SATURDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.2N 56.1W
ABOUT 460 MI...740 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES



Hurricane Erin Discussion Number 17
NWS National Hurricane Center Miami FL AL052025
1100 AM AST Fri Aug 15 2025

Erin has become better organized during the past several hours. The
last few NOAA and Air Force Reserve aircraft passes through the
cyclone have indicated the formation of an eyewall, with the Air
Force Reserve aircraft reporting 700-mb flight-level winds of 75 kt
northeast of the center. In addition, conventional satellite imagery
shows the development of a central dense overcast, and a recently
received WSFM microwave overpass shows a well-defined ring of
shallow to moderate convection in the 37 GHz imagery. Based on
these data, the initial intensity is increased to 65 kt and Erin
becomes the first hurricane of the 2025 Atlantic Hurricane Season.

The initial motion is 290/15. The subtropical ridge to the north
will continue to steer Erin west-northwestward into the weekend.
Encroaching mid-latitude westerly flow is forecast to cause a
weakness to develop in the ridge during the latter part of the
forecast period, and this will result in the hurricane gradually
turning northwestward and northward by 120 h. The guidance remains
in fairly good agreement through about 60-72 hours. After that time,
there are some differences in both the forward speed and cross-track
spread with the turn toward the north. The regional hurricane models
again lie along the western edge of the guidance envelope, while the
GFS and Google DeepMind models remain on the eastern edge. Although
still spread, the guidance envelope has not shifted significantly
since the last advisory, and the new track forecast is an update of
the previous forecast. There is still uncertainty about what impacts
Erin may bring to portions of the Bahamas, the east coast of the
United States, and Bermuda in the long range.

Erin is currently in a favorable environment for strengthening,
although there are some uncertainties on whether dry air is
entraining into the core. The improved low-level structure
indicates potential for rapid strengthening, and based on this the
first 36-48 h of the new intensity forecast shows a faster
development rate. After 48 h, the hurricane is forecast to
encounter some northerly to northwesterly vertical shear that should
at least slow development. However, the global and regional
hurricane models are in good agreement that Erin will become a
powerful and increasingly large hurricane over the southwestern
Atlantic over the weekend and into next week. It should be noted
that the the Florida State SuperEnsemble and the US Navy COAMPS-TC
models forecast higher peak intensities than the official forecast,
so it would not be too surprising if Erin became stronger than
currently forecast.

KEY MESSAGES:

1. Heavy rainfall tonight through Sunday across the northern Leeward
Islands, the Virgin Islands, and Puerto Rico may lead to isolated
and locally considerable flash and urban flooding, along with
landslides or mudslides.

2. Tropical storm conditions are possible for portions of the
northern Leeward Islands, where Tropical Storm Watches are in
effect, beginning on Saturday as the core of Erin passes north of
those islands. Gusts to tropical storm force are possible in
rainbands over portions of the Virgin Islands and Puerto Rico later
in the weekend.

3. While the threat of direct impacts in the Bahamas and along the
east coast of the United States appears to be gradually decreasing,
there will still be a significant risk of dangerous surf and rip
currents along western Atlantic beaches next week.

4. Interests in Bermuda should continue to monitor the progress of
Erin since there is still a risk of strong winds, heavy rainfall,
and high surf by the middle part of next week.


FORECAST POSITIONS AND MAX WINDS

INIT 15/1500Z 18.2N 56.1W 65 KT 75 MPH
12H 16/0000Z 18.9N 58.4W 75 KT 85 MPH
24H 16/1200Z 19.8N 61.4W 90 KT 105 MPH
36H 17/0000Z 20.6N 63.8W 105 KT 120 MPH
48H 17/1200Z 21.6N 66.0W 110 KT 125 MPH
60H 18/0000Z 22.7N 67.9W 115 KT 130 MPH
72H 18/1200Z 23.8N 69.2W 120 KT 140 MPH
96H 19/1200Z 26.5N 70.8W 115 KT 130 MPH
120H 20/1200Z 30.3N 71.0W 110 KT 125 MPH

$$
Forecaster Beven