NATL: GABRIELLE - Advisories

[cycloneye]

BULLETIN
Tropical Depression Seven Advisory Number 1
NWS National Hurricane Center Miami FL AL072025
500 AM AST Wed Sep 17 2025

...TROPICAL DEPRESSION FORMS OVER THE CENTRAL ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.7N 45.9W
ABOUT 1185 MI...1905 KM ESE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES





Tropical Depression Seven Discussion Number 1
NWS National Hurricane Center Miami FL AL072025
500 AM AST Wed Sep 17 2025

Satellite data indicate that Invest 92L over the central tropical
Atlantic has now developed into a tropical depression. ASCAT data
from around 00Z showed that the circulation of the system had
improved, and although it was not well defined at the time of the
pass, the system was only lacking some northerly winds on its west
side. Since deep convection has been persisting and consolidating
near the center, it appears to now meet the convective and
circulation criteria needed to be considered a tropical cyclone.
However, it should be noted that the system is quite large and there
is still considerable north-south elongation in the low-level
structure. The initial intensity is set at 30 kt based on a blend of
the ASCAT data and the latest Dvorak estimate from TAFB. The
development of this system breaks a nearly 3-week streak of no
tropical cyclones in the Atlantic basin during the peak of the
hurricane season.

The depression is well away from land and roughly midway between the
Cabo Verde Islands and the Windward Islands. The system is
estimated to be moving westward at 11 kt, but this is of low
confidence since the center has only recently formed. A turn to the
northwest, perhaps influenced by a center formation, is expected to
occur soon as the depression moves toward a weakness in the Atlantic
subtropical ridge caused by a mid- to upper-level low to its north.
The models show this low weakening in a day or two, which will
likely cause the cyclone to turn back to the west-northwest late
this week. However, the system should reach the western periphery
of the ridge this weekend, resulting in a turn to the northwest or
north. The NHC track forecast is a little to the right of the
consensus aids, giving more weight to the ECMWF and Google Deep Mind
predictions, which are faster and on the right side of the guidance.
Based on the steering pattern, and deterministic and ensemble model
solutions, there is high confidence that this system should pass
well east of the Windward and Leeward Islands. Interests in Bermuda
should monitor forecasts of the depression over the next several
days.

Only modest strengthening is expected over the next day or two as
the depression continues to battle moderate shear from the
aforementioned low aloft and intrusions of dry air. However, more
notable strengthening seems likely by the weekend when the system
moves into more conducive environmental conditions. The NHC
intensity forecast shows the system reaching hurricane strength
toward the end of the period, but it should be noted that the spread
in the models at that time is significant and ranges from solutions
showing a weak low to a major hurricane. This prediction is
generally in line with the IVCN aid.


FORECAST POSITIONS AND MAX WINDS

INIT 17/0900Z 13.7N 45.9W 30 KT 35 MPH
12H 17/1800Z 15.8N 47.4W 35 KT 40 MPH
24H 18/0600Z 17.6N 49.6W 40 KT 45 MPH
36H 18/1800Z 19.0N 51.9W 40 KT 45 MPH
48H 19/0600Z 19.7N 54.0W 45 KT 50 MPH
60H 19/1800Z 20.4N 55.9W 50 KT 60 MPH
72H 20/0600Z 21.6N 57.6W 55 KT 65 MPH
96H 21/0600Z 24.0N 60.0W 65 KT 75 MPH
120H 22/0600Z 26.9N 63.0W 75 KT 85 MPH

$$
Forecaster Cangialosi

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 2
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Wed Sep 17 2025

...GABRIELLE FORMS OVER THE CENTRAL TROPICAL ATLANTIC...
...FORECAST TO REMAIN OVER OPEN WATERS FOR SEVERAL DAYS...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.5N 46.6W
ABOUT 1085 MI...1745 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 22 MPH...35 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES



Tropical Storm Gabrielle Discussion Number 2
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Wed Sep 17 2025

Satellite imagery this morning indicates that the large system is
not well-organized, with an elongated circulation
oriented from north-northwest to south-southeast containing a few
embedded swirls. The advisory center is a mean center of those
swirls, with any associated convection well east of the position due
to southwesterly shear. While it wouldn't appear so from
conventional satellite data, a recent scatterometer pass indicates
upwards of 40-kt winds present, generally northeast and southeast of
the center of circulation. Although the system is at best
marginally well defined, there is enough data to support an initial
intensity of 40 kt, and the depression is named Gabrielle.

Little strengthening is anticipated over the next 48 hours as
Gabrielle faces an unfavorable shear environment from an
upper-level trough and a possible center re-formation, and the
forecast intensity remains nearly steady through Friday. By this
weekend, a more conducive environment is anticipated, which should
allow for gradual intensification. Gabrielle is forecast to become
a hurricane by 96 hours. The NHC intensity forecast remains
fairly similar to the previous forecast cycle, but it should be
noted that there remains considerable spread in the solutions and
overall forecast intensity confidence is low.

Gabrielle is well away from land and about midway between the Cabo
Verde Islands and the Windward Islands. The current estimated
motion is north-northwestward, but this is highly uncertain as the
center could be re-forming to the north. The system is forecast to
move northwestward to west-northwestward due to the subtropical
ridge for the next several days. While the forecast has been
adjusted to the north from the previous one, this is almost
exclusively due to the jump in the initial position. This is a
highly uncertain forecast until a better defined center forms.
Based on the recent trends, this system should pass well east and
north of the Windward and Leeward Islands, but interests in Bermuda
should monitor forecasts during the next several days.

FORECAST POSITIONS AND MAX WINDS

INIT 17/1500Z 17.5N 46.6W 40 KT 45 MPH
12H 18/0000Z 19.5N 48.5W 45 KT 50 MPH
24H 18/1200Z 20.8N 50.6W 45 KT 50 MPH
36H 19/0000Z 21.8N 52.6W 45 KT 50 MPH
48H 19/1200Z 22.7N 54.6W 45 KT 50 MPH
60H 20/0000Z 23.5N 56.6W 50 KT 60 MPH
72H 20/1200Z 24.7N 58.3W 55 KT 65 MPH
96H 21/1200Z 27.4N 60.8W 65 KT 75 MPH
120H 22/1200Z 30.0N 62.5W 75 KT 85 MPH

$$
Forecaster Taylor/Blake

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 3
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
500 PM AST Wed Sep 17 2025

...CENTER OF GABRIELLE RE-FORMS NORTH OF THE PREVIOUS ADVISORY
POSITION...

SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...19.4N 48.0W
ABOUT 990 MI...1595 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES



Tropical Storm Gabrielle Discussion Number 3
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
500 PM AST Wed Sep 17 2025

The biggest change with Gabrielle today has been that the center
has re-formed farther to the north compared with the previous
advisory, similar to earlier model forecasts. While satellite
imagery continues to indicate an elongated circulation with
multiple embedded swirls, it has become better defined than this
morning, and we have continued to make the center position on the
advisory a mean of those swirls. A second scatterometer pass that
intersected the northern semicircle of the storm after the 15Z
advisory did show a large area of 40-45 kt winds. Therefore, the
initial intensity has been increased to 45 knots, even though the
system does not appear appreciably more organized.

The first part of the track forecast has been shifted to the north
based on the recent center re-formation. Gabrielle is moving
northwestward now, and a west-northwestward to northwestward track
is anticipated for the next few days due to steering from the
subtropical ridge. The fundamental forecast question for both
track and intensity is related to the wind shear Gabrielle will
experience and the structural change. Little intensity change is
shown for the next couple of days while the storm remains in a
high-shear but high SST/instability environment. There actually
appears to be good consensus that the shear will relax after Friday,
but there are significant model differences on how much. This leads
to a considerable amount of track and intensity spread as the
forecast progresses into the weekend. Generally the models that
relax the shear more substantially, to around 10 knots or less, show
more intensification and a track to the right of model consensus.
Since the NHC intensity forecast is a bit above the model average
(similar to the last prediction), we favor a track forecast to the
right of the model blend, more consistent with the HCCA corrected
consensus, Google Deep Mind ensemble, and ECMWF ensemble.

Overall, forecast confidence remains relatively low. Based on the
recent trends, this system should pass well east and north of the
Windward and Leeward Islands, but interests in Bermuda should
monitor forecasts during the next several days.

FORECAST POSITIONS AND MAX WINDS

INIT 17/2100Z 19.4N 48.0W 45 KT 50 MPH
12H 18/0600Z 20.6N 49.7W 45 KT 50 MPH
24H 18/1800Z 21.7N 51.6W 45 KT 50 MPH
36H 19/0600Z 22.7N 53.5W 45 KT 50 MPH
48H 19/1800Z 23.5N 55.5W 45 KT 50 MPH
60H 20/0600Z 24.7N 57.4W 50 KT 60 MPH
72H 20/1800Z 26.2N 59.0W 55 KT 65 MPH
96H 21/1800Z 29.0N 62.0W 65 KT 75 MPH
120H 22/1800Z 32.0N 62.5W 75 KT 85 MPH

$$
Forecaster Lamers/Blake

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 4
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Wed Sep 17 2025

...POORLY ORGANIZED GABRIELLE BATTLING STRONG WIND SHEAR AS IT JOGS
TOWARD THE WEST-NORTHWEST...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.5N 49.5W
ABOUT 895 MI...1435 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Gabrielle Discussion Number 4
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Wed Sep 17 2025

The overall structure of Gabrielle hasn't changed too much. The
cloud pattern of the cyclone consists of a large comma shape.
GOES-19 CIRA proxy-vis imagery and a recent 17/2342 UTC ASCAT-B
overpass clearly indicate that the surface wind center is at the
bottom of the upper portion of the comma head. The strongest ASCAT
wind vectors are the same magnitudes as the pass from 12 hours
prior, so the intensity is held at 45 kt for this advisory.

Gabrielle still has a very large and broad envelope of convection
and winds. It is quite atypical to see a structure like this for a
tropical cyclone in this part of the world. Strong westerly shear
should continue on Thursday, then gradually abate at some point on
Friday. The other factor that is detrimentally impacting Gabrielle
is the very dry air seen on water vapor imagery in the open area of
the comma, to the south and west of the center. Even after the
shear abates, Gabrielle will continue moving through an environment
of dry air through Friday, with moistening along its path over the
weekend. The official intensity forecast has been decreased during
the 24-48 h period, in agreement with most of the reliable intensity
guidance. The new NHC intensity forecast is near the middle of the
guidance envelope through 48 hours, then near the high end of the
guidance thereafter, and still calls for Gabrielle to be a hurricane
at days 4-5.

The center has jogged westward since the previous advisory, but the
longer term motion is estimated to be west-northwestward, or 300/14
kt. A similar motion is expected for the next couple of days,
followed by a gradual turn toward the west-northwest as Gabrielle
moves on the south side of a subtropical ridge. Over the weekend,
the cyclone should round the southwestern periphery of the ridge and
turn northwestward as it catches up to a slow-moving upper-level low
that should be located just west of Gabrielle. A northward motion
is expected in 4-5 days as Gabrielle gets closer to the mid-latitude
westerlies, which should induce a northeastward turn in about 5
days. The new NHC track forecast is shifted significantly to the
left (southwest) of the previous forecast through 72 h but near the
previous track again at days 4-5. The forecast is in fairly good
agreement with the Google Deep Mind ensemble mean through 72 h, then
leans toward the HCCA Corrected Consensus at days 4-5.

Track forecast confidence remains relatively low. This system
should pass well east and north of the Leeward Islands, but
interests in Bermuda should monitor forecasts during the next
several days.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0300Z 19.5N 49.5W 45 KT 50 MPH
12H 18/1200Z 20.3N 51.0W 45 KT 50 MPH
24H 19/0000Z 21.3N 52.9W 40 KT 45 MPH
36H 19/1200Z 22.2N 54.9W 40 KT 45 MPH
48H 20/0000Z 23.3N 56.9W 40 KT 45 MPH
60H 20/1200Z 24.5N 58.8W 45 KT 50 MPH
72H 21/0000Z 25.8N 60.3W 50 KT 60 MPH
96H 22/0000Z 28.9N 62.7W 65 KT 75 MPH
120H 23/0000Z 32.5N 62.0W 75 KT 85 MPH

$$
Forecaster Hagen

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 5
NWS National Hurricane Center Miami FL AL072025
500 AM AST Thu Sep 18 2025

...GABRIELLE STRUGGLING OVER THE CENTRAL ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...20.0N 50.3W
ABOUT 845 MI...1360 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Gabrielle Discussion Number 5
NWS National Hurricane Center Miami FL AL072025
500 AM AST Thu Sep 18 2025

Gabrielle continues to struggle and consists of a swirl of low-level
clouds with patches of deep convection over the northeast and
southeast quadrants of the storm. The poor structure is due to
westerly vertical wind shear and a significant amount of dry air
that is continuously entraining into the circulation. The initial
intensity is held at 45 kt based on the earlier ASCAT data, but this
value is well above the latest satellite intensity estimates.

The atmospheric conditions are expected to remain hostile for a
couple more days, so it seems likely that Gabrielle will either hold
steady or lose strength during that time. However, the models
suggest that the storm could move into more conducive conditions
late in the weekend and early next week, which should cause
Gabrielle to become more symmetric and strengthen. The NHC
intensity forecast is near the middle of the guidance envelope for
the first 3 days, but lies closer to the high end of the guidance at
days 4 and 5.

Gabrielle has been moving erratically due to the storm
reorganizing over the past 12 to 24 hours, but smoothing through
the fixes yields a west-northwestward motion at 13 kt. A continued
west-northwest to northwest motion at about the same forward speed
is expected during the next few days as the storm continues to be
primarily steered by a subtropical ridge over the central Atlantic.
A turn toward the north or northeast is forecast to occur late this
weekend and early next week when Gabrielle rounds the western
periphery of the ridge. The NHC track forecast is very similar to
the previous one from 12 to 72 h, but it has been shifted a little
to the right at days 4 and 5 to be in better agreement with the
latest guidance.

Confidence in the long range forecast remains low, and interests in
Bermuda should continue to monitor Gabrielle over the next several
days.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 20.0N 50.3W 45 KT 50 MPH
12H 18/1800Z 20.8N 51.7W 40 KT 45 MPH
24H 19/0600Z 21.8N 53.6W 40 KT 45 MPH
36H 19/1800Z 22.8N 55.7W 40 KT 45 MPH
48H 20/0600Z 24.0N 57.7W 40 KT 45 MPH
60H 20/1800Z 25.3N 59.4W 45 KT 50 MPH
72H 21/0600Z 26.8N 60.7W 50 KT 60 MPH
96H 22/0600Z 30.2N 61.5W 65 KT 75 MPH
120H 23/0600Z 34.4N 58.3W 75 KT 85 MPH

$$
Forecaster Cangialosi

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 6
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Thu Sep 18 2025

...GABRIELLE STILL STRUGGLING OVER THE CENTRAL ATLANTIC...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.3N 51.7W
ABOUT 755 MI...1220 KM ENE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Gabrielle Discussion Number 6
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Thu Sep 18 2025

Gabrielle continues to struggle this morning as a pronounced swirl
of low-level clouds is unable to muster up much in the way of deep
convection near its center. Gabrielle's poor structure is due to
ongoing westerly vertical wind shear and a significant amount of
dry air entrainment that is infiltrating its circulation. The
initial intensity is held at 45 kt based on recent scatterometer
data of at least 40 kt, but this value remains above the latest
satellite intensity estimates.

Atmospheric conditions are expected to remain hostile for a
couple more days, meaning Gabrielle is likely maintain its
current intensity or weaken during that time. It is even possible
it could decay into a non-convective post-tropical low for a time.
Assuming it survives, most guidance suggests that the storm will
move into more conducive conditions that persist into early next
week, allowing Gabrielle to organize and strengthen as it tracks
north to northeastward. The NHC intensity forecast is near the low
end of the guidance envelope for the first 3 days, but lies closer
to the middle of the guidance at days 4 and 5.

Gabrielle's more erratic track over the past 24-48 hours has now
smoothed out over the past 12-24 hours with a west-northwestward
motion at 13 kt. This west-northwest to northwest motion should
persist over the next few days as the storm is steered primarily by
a subtropical ridge over the central Atlantic. A turn toward the
north or northeast is forecast to occur late this weekend and early
next week when Gabrielle rounds the western periphery of the ridge
and a frontal system approaches from the west. The NHC track
forecast was adjusted just west of track given the guidance's more
westerly consensus of a weaker system inside the next 48 hours.
Gabrielle's forward motion is a little faster as well, especially
between hours 48-120 when it should accelerate thanks to increased
steering flow on the western side of the Atlantic ridge.

Confidence in the long range forecast remains low, and interests in
Bermuda should continue to monitor Gabrielle over the next several
days.


FORECAST POSITIONS AND MAX WINDS

INIT 18/1500Z 20.3N 51.7W 45 KT 50 MPH
12H 19/0000Z 21.1N 53.2W 40 KT 45 MPH
24H 19/1200Z 22.1N 55.3W 40 KT 45 MPH
36H 20/0000Z 23.2N 57.4W 40 KT 45 MPH
48H 20/1200Z 24.4N 59.2W 40 KT 45 MPH
60H 21/0000Z 25.9N 60.6W 45 KT 50 MPH
72H 21/1200Z 27.7N 61.5W 50 KT 60 MPH
96H 22/1200Z 31.4N 61.9W 70 KT 80 MPH
120H 23/1200Z 36.5N 56.2W 80 KT 90 MPH

$$
Forecaster Mullinax/Blake

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 7
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
500 PM AST Thu Sep 18 2025

...GABRIELLE FORECAST TO STRENGTHEN THIS WEEKEND...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...20.8N 52.7W
ABOUT 700 MI...1125 KM ENE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Gabrielle Discussion Number 7
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
500 PM AST Thu Sep 18 2025

Gabrielle continues to fight off strong westerly vertical
wind shear and significant dry air entrainment this afternoon.
Some thunderstorms have blossomed on the storm's eastern flank,
which is an improvement from its naked low-level swirl earlier this
morning. The initial intensity is held at 45 kt based on recent
scatterometer data of at least 40 kt and little in the way of
change to its structure from earlier this morning.

Atmospheric conditions are expected to remain hostile for another
day or so, meaning Gabrielle is likely maintain its current
intensity or weaken slightly during that time. Recent 12Z guidance
indicates vertical wind shear relaxes and an increasingly moist
vertical profile should foster a much improved environment for
strengthening this weekend, with the GFS model trending toward the
more conducive ECMWF solution. As a result, intensity guidance is
notable higher on this cycle. The NHC intensity forecast is raised
from the previous one, but not as high as the model consensus
mostly due to continuity. There are a growing number of hurricane
models that are indicating Gabrielle could approach major hurricane
strength after the weekend.

Gabrielle is moving west-northwestward at 13 kt and should maintain
this track with a bend toward the northwest over the next few days
as the storm is steered primarily by a subtropical ridge over the
central Atlantic. A turn toward the north and northeast is
forecast to occur late this weekend and early next week when
Gabrielle rounds the western periphery of the ridge and a frontal
system approaches from the west. While the guidance envelope has
shrunk on this forecast cycle, there are some significant speed
differences, with the ECMWF/GFS models considerably faster than the
Google Deep Mind ensemble. Although no significant changes to the
forecast were made, confidence remains on the lower side given the
along-track model spread and an unclear intensity forecast beyond
48 hours. Interests in Bermuda should continue to monitor Gabrielle
over the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 18/2100Z 20.8N 52.7W 45 KT 50 MPH
12H 19/0600Z 21.5N 54.2W 40 KT 45 MPH
24H 19/1800Z 22.6N 56.3W 40 KT 45 MPH
36H 20/0600Z 23.9N 58.1W 45 KT 50 MPH
48H 20/1800Z 25.3N 59.8W 50 KT 60 MPH
60H 21/0600Z 27.1N 61.1W 55 KT 65 MPH
72H 21/1800Z 29.0N 62.0W 65 KT 75 MPH
96H 22/1800Z 33.0N 61.0W 85 KT 100 MPH
120H 23/1800Z 39.0N 52.5W 80 KT 90 MPH

$$
Forecaster Mullinax/Blake

NNNN

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 8
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Thu Sep 18 2025

...GABRIELLE HOLDING STEADY OVER THE CENTRAL ATLANTIC...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...21.2N 53.4W
ABOUT 665 MI...1070 KM ENE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Gabrielle Discussion Number 8
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Thu Sep 18 2025

Gabrielle has managed to re-develop deep convection near its
low-level center this evening. Thunderstorms in the northeast
quadrant formed early in the afternoon and have continued into the
evening, producing cloud top temperatures colder than -80 degrees C.
A scatterometer pass from 0012 UTC measured the eastern portion of
the circulation with wind speeds close to 40 kt. However, these
data did not capture the radius of maximum wind, which is assumed to
have stronger winds. Therefore, the initial intensity is held at 45
kt for this advisory.

Global models suggest environmental conditions will be unfavorable
for the next day or so while Gabrielle contends with
strong-to-moderate vertical wind shear and dry air intrusions. By
this weekend, both of these impediments should subside and allow the
storm to gradually strengthen. Once again, the intensity aids have
risen this cycle. The NHC intensity forecast has been nudged upward
and now lies in the middle of the guidance envelope with a peak of
90 kt by day 4.

Gabrielle is moving west-northwestward at 10 kt. The storm should
slowly turn toward the northwest over the next few days around the
periphery of a subtropical ridge centered over the central Atlantic.
Late this weekend and into early next week, the storm is expected to
turn toward the north and northeast in the flow between the ridge
and a frontal system approaching from the west. There are still
some speed differences among the numerical models, however the
overall track guidance spread is not as significant this cycle. The
latest official track forecast is slightly east of the previous
prediction and lies between the consensus aids to the west and
Google DeepMind to the east. Interests in Bermuda should continue to
monitor Gabrielle over the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT 19/0300Z 21.2N 53.4W 45 KT 50 MPH
12H 19/1200Z 22.0N 54.9W 45 KT 50 MPH
24H 20/0000Z 23.2N 56.8W 45 KT 50 MPH
36H 20/1200Z 24.5N 58.4W 50 KT 60 MPH
48H 21/0000Z 26.1N 59.9W 55 KT 65 MPH
60H 21/1200Z 28.0N 61.0W 60 KT 70 MPH
72H 22/0000Z 29.9N 61.4W 70 KT 80 MPH
96H 23/0000Z 34.6N 58.6W 90 KT 105 MPH
120H 24/0000Z 40.1N 48.6W 80 KT 90 MPH

$$
Forecaster Bucci

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 9
NWS National Hurricane Center Miami FL AL072025
500 AM AST Fri Sep 19 2025

...GABRIELLE FORECAST TO STRENGTHEN AND BECOME A HURRICANE BY
SUNDAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...21.9N 54.8W
ABOUT 595 MI...960 KM ENE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 945 MI...1520 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Gabrielle Discussion Number 9
NWS National Hurricane Center Miami FL AL072025
500 AM AST Fri Sep 19 2025

Gabrielle's low-level center is located near the western edge of an
area of deep convection that has now persisted since late yesterday
afternoon. While the overall convective structure is gradually
improving, the change hasn't been enough to deviate from a current
intensity of 45 kt. UW-CIMSS SATCON, with a value of 42 kt, is
currently the closest satellite intensity estimate.

The storm is maintaining a west-northwestward heading of 300 degrees
at 10 kt, with the subtropical ridge located to its north. A
general pattern of troughing is expected to persist near the
southeastern U.S. coast and far western Atlantic for the next
several days, which should cause Gabrielle to recurve around the
western periphery of the ridge over the next 4 days. There has
been further tightening of the track guidance during this period,
including a convergence of the HCCA and Google DeepMind ensemble
mean, and no significant adjustments were required for this updated
track forecast. The reliable track models now show Gabrielle's
center passing at least 140 n mi east of Bermuda in about 3 days.
However, interests on the island should continue to monitor
Gabrielle's progress since NHC's average track error at 3 days is
about 90 n mi, and hazards can extend well away from the center.
There is currently a 20-25 percent chance of tropical-storm-force
winds occurring on Bermuda.

The moderate westerly shear currently affecting Gabrielle is
forecast to gradually lessen below 10 kt by 36 hours. This should
begin to mitigate the effects of surrounding dry air and allow for
gradual strengthening. The NHC intensity forecast has been nudged
upward, particularly during the first 3 days, to trend toward the
latest IVCN and HCCA consensus aids, and Gabrielle is expected
to become a hurricane by Sunday. The forecast peak intensity on
day 4 is unchanged. By day 5, the onset of significantly stronger
shear and cooler waters should induce some weakening. At the
moment, there is significant uncertainty about when Gabrielle might
become extratropical and how that would affect the cyclone's
intensity.

KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should monitor Gabrielle's forecasts since it is too soon to
specify the magnitude of potential wind and rainfall impacts.

2. Swells generated by Gabrielle are expected to reach Bermuda
tonight and build through the weekend. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 19/0900Z 21.9N 54.8W 45 KT 50 MPH
12H 19/1800Z 22.6N 56.0W 45 KT 50 MPH
24H 20/0600Z 23.9N 57.7W 50 KT 60 MPH
36H 20/1800Z 25.4N 59.2W 55 KT 65 MPH
48H 21/0600Z 27.1N 60.3W 60 KT 70 MPH
60H 21/1800Z 28.9N 61.2W 70 KT 80 MPH
72H 22/0600Z 31.0N 61.2W 80 KT 90 MPH
96H 23/0600Z 35.9N 56.9W 90 KT 105 MPH
120H 24/0600Z 39.8N 46.0W 75 KT 85 MPH

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 10
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Fri Sep 19 2025

...GABRIELLE FORECAST TO STRENGTHEN AND BECOME A HURRICANE BY
SUNDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...21.9N 55.6W
ABOUT 550 MI...885 KM ENE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 915 MI...1470 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Gabrielle Discussion Number 10
NWS National Hurricane Center Miami FL AL072025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM AST Fri Sep 19 2025

Gabrielle's low-level center remains mostly exposed, now between a
large area of deep convection in the eastern semicircle and growing
cells in the southwestern quadrant. There has been little change in
the satellite estimates and since scatterometer missed the
radius-of-maximum winds this morning, the initial intensity will
remain 45 kt.

The storm is moving northwestward or 305 degrees at 10 kt, with the
subtropical ridge located to its north. A general pattern of
troughing is expected to persist near the southeastern U.S. coast
and far western Atlantic for the next several days, which is
expected cause Gabrielle to recurve around the western periphery of
the ridge over the next 4 days. While the track guidance remains
relatively tight during this period, the along-track spread (speed
differences) are quite large in the medium range. The HCCA and
Google DeepMind (GDM) ensemble mean have bifurcated on the latest
cycle with the corrected consensus to the north and the GDM to the
south. Our forecast has adjusted slightly north, but remains on the
southern side of the overall consensus. The reliable track models
continue to show Gabrielle's center passing at least 140 n mi east
of Bermuda in about 3 days. However, interests on the island should
continue to monitor Gabrielle's progress since NHC's average track
error at 3 days is about 90 n mi, and hazards can extend well away
from the center. There remains a 20-25 percent chance of
tropical-storm-force winds occurring on Bermuda.

The moderate westerly shear currently affecting Gabrielle is
forecast to gradually lessen below 10 kt by 24-36 hours. This should
begin to mitigate the effects of surrounding dry air and allow for
gradual strengthening. The NHC intensity forecast has once again
been raised to trend toward the latest IVCN and HCCA consensus aids,
and Gabrielle is expected to become a hurricane by Sunday. By day 5,
the onset of significantly stronger shear and cooler waters should
induce some weakening. There is significant uncertainty about when
Gabrielle might become extratropical, as the forward speed of the
system may contribute significantly to a higher peak intensity
(longer time over warmer waters).


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should monitor Gabrielle's forecasts since it is too soon to
specify the magnitude of potential wind and rainfall impacts.

2. Swells generated by Gabrielle are expected to reach Bermuda
tonight and build through the weekend. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 19/1500Z 21.9N 55.6W 45 KT 50 MPH
12H 20/0000Z 22.9N 56.9W 45 KT 50 MPH
24H 20/1200Z 24.3N 58.5W 50 KT 60 MPH
36H 21/0000Z 26.0N 59.8W 55 KT 65 MPH
48H 21/1200Z 27.8N 60.8W 65 KT 75 MPH
60H 22/0000Z 29.8N 61.2W 75 KT 85 MPH
72H 22/1200Z 32.0N 60.9W 85 KT 100 MPH
96H 23/1200Z 37.5N 54.0W 95 KT 110 MPH
120H 24/1200Z 41.3N 40.2W 75 KT 85 MPH

$$
Forecaster Churchill/Blake

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 11
NWS National Hurricane Center Miami FL AL072025
500 PM AST Fri Sep 19 2025

...GABRIELLE STARTING TO GET BETTER ORGANIZED...
...FORECAST TO STRENGTHEN AND BECOME A HURRICANE BY SUNDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...22.4N 56.6W
ABOUT 510 MI...820 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 850 MI...1365 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Gabrielle Discussion Number 11
NWS National Hurricane Center Miami FL AL072025
500 PM AST Fri Sep 19 2025

Gabrielle's cloud pattern has changed significantly since the last
advisory. The previously noted shear pattern has changed to a curved
convective band pattern, and the previously exposed low-level center
has become at least partly covered by cirrus clouds spreading
westward from the convection. This change suggests that the storm
is starting to encounter the forecast decrease in vertical shear.
At this time, this change has not led to an increase in the various
satellite intensity estimates, so the initial intensity remains 45
kt.

The initial motion is 300/10 kt. Gabrielle is on the southwest side
of the subtropical ridge, and during the next 2-3 days it is
expected to turn northward between the ridge to the east and and a
mid-latitude trough over the eastern United States and the far
western Atlantic. The track guidance remains fairly tightly
clustered during this time, although the consensus models have
shifted a little to the left since the last advisory. This part of
the new forecast track is nudged a little to the left, but still
lies east of the consensus models. After 3 days, Gabrielle is
expected to recurve into the westerlies and accelerate
northeastward. The guidance shows more spread during this time, with
the GFS being to the left/north and faster than most of the
guidance, while the ECMWF is to the right/south and slower. Despite
the spread, the consensus models and the center of the guidance
envelope are have changed little since the last advisory for this
part of the forecast. Thus, the new forecast is similar to, but
slightly slower than, the previous forecast. The reliable track
models still show Gabrielle's center passing at least 130 n mi east
of Bermuda in 60-72 h. However, interests on the island should
continue to monitor Gabrielle's progress since NHC's average track
error at 72 h is about 90 n mi, and hazards can extend well away
from the center. There remains a 20-25 percent chance of
tropical-storm-force winds occurring on Bermuda.

Gabrielle is now forecast to be in a light-to-moderate shear
environment for the next 72 h, which should allow strengthening
that would be tempered mainly by occasional entrainment of dry air.
The new intensity forecast has been tweaked a bit to show a peak
intensity of 90 kt at 72 h. Extratropical transition should be
underway by 120 h, and could be complete by that time if the
cyclone takes a more northward track similar to the GFS. However, a
more southward track similar to the ECMWF would delay transition,
and based on the uncertainty the new intensity forecast keeps the
system as a tropical cyclone at 120 h.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should monitor Gabrielle's forecasts since it is too soon to
specify the magnitude of potential wind and rainfall impacts.

2. Swells generated by Gabrielle are expected to reach Bermuda
tonight and build through the weekend. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 19/2100Z 22.4N 56.6W 45 KT 50 MPH
12H 20/0600Z 23.5N 58.0W 45 KT 50 MPH
24H 20/1800Z 25.0N 59.4W 55 KT 65 MPH
36H 21/0600Z 26.8N 60.6W 65 KT 75 MPH
48H 21/1800Z 28.6N 61.4W 75 KT 85 MPH
60H 22/0600Z 30.6N 61.6W 85 KT 100 MPH
72H 22/1800Z 33.0N 59.9W 90 KT 105 MPH
96H 23/1800Z 38.1N 51.3W 90 KT 105 MPH
120H 24/1800Z 42.1N 38.4W 70 KT 80 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 12
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Fri Sep 19 2025

...GABRIELLE FORECAST TO BECOME A HURRICANE BY SUNDAY...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...23.6N 57.2W
ABOUT 535 MI...855 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 760 MI...1220 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Gabrielle Discussion Number 12
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Fri Sep 19 2025

Gabrielle still has the appearance of a sheared tropical storm.
Before sunset, the low-level center was just west of the deep
convection and recent bursts have partially obscured it now. A GPM
microwave pass showed a couple bands curving around the eastern
semicircle of the storm. Satellite Dvorak estimates have remained
steady since the previous advisory and the intensity is held at 45
kt, closest to the TAFB classification of T3.0/45-kt.

The storm is moving northwestward at 10 kt as it is steered by a
subtropical ridge over the central Atlantic. In about a day,
Gabrielle will turn to the north-northwest and the north while it
moves between the western periphery of the ridge and a mid-latitude
trough over the eastern United States. The storm should turn more
towards the northeast and accelerate in the mid-latitude westerlies
by early next week. The track guidance has a noticeably slower
forward motion this cycle and by the end of the forecast period, is
farther south. Overall, the latest NHC track forecast is slower
than the previous prediction. It is also farther east for the first
48 hours, largely due to the initial position being farther north
than expected. Interest in Bermuda should continue to monitor
Gabrielle's progress since there is a roughly 20 percent chance of
tropical-storm-force winds occurring on Bermuda.

Gabrielle is expected to gradually strengthen as the environmental
conditions become more conducive during the next few days. The
system should reach hurricane strength by Sunday and is forecast to
peak at 90 kt at 72 h. This forecast is closest to the corrected
consensus aid, HCCA. It should be noted that several of the
hurricane regional models still predict that Gabrielle could reach
major hurricane strength by early next week. At the end of the
forecast period, extratropical transition could be underway but
with the southward adjustment to the track forecast, the official
forecast does not explicitly call for it yet.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should monitor Gabrielle's forecasts since it is too soon to
specify the magnitude of potential wind and rainfall impacts.

2. Swells generated by Gabrielle are expected to reach Bermuda
soon and build through the weekend. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 20/0300Z 23.6N 57.2W 45 KT 50 MPH
12H 20/1200Z 24.7N 58.3W 50 KT 60 MPH
24H 21/0000Z 26.3N 59.6W 55 KT 65 MPH
36H 21/1200Z 28.0N 60.7W 65 KT 75 MPH
48H 22/0000Z 30.0N 61.3W 75 KT 85 MPH
60H 22/1200Z 32.0N 60.8W 85 KT 100 MPH
72H 23/0000Z 34.5N 58.2W 90 KT 105 MPH
96H 24/0000Z 38.9N 49.0W 85 KT 100 MPH
120H 25/0000Z 42.7N 35.6W 70 KT 80 MPH

$$
Forecaster Bucci

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 13
NWS National Hurricane Center Miami FL AL072025
500 AM AST Sat Sep 20 2025

...GABRIELLE MOVING NORTHWESTWARD...
...EXPECTED TO BECOME A HURRICANE AND PASS EAST OF BERMUDA SUNDAY
NIGHT AND MONDAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...24.3N 58.1W
ABOUT 530 MI...855 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 685 MI...1105 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES

Tropical Storm Gabrielle Discussion Number 13
NWS National Hurricane Center Miami FL AL072025
500 AM AST Sat Sep 20 2025

Although Gabrielle's low-level center is obscured by high cirrus
clouds, an 0555 UTC AMSR2 microwave pass confirms that it is still
located to the west of the deep convective mass due to continued
moderate westerly shear. The convection itself has been quite
intense, with a high density of lightning co-located with cloud-top
temperatures as cold as -85 to -90 degrees Celsius. The latest
satellite intensity estimates, as well as ASCAT data from yesterday
evening, still support an intensity of 45 kt. The ASCAT data also
showed that there are currently no tropical-storm-force winds on
Gabrielle's western side.

Mid-tropospheric high pressure over the central Atlantic is
steering Gabrielle northwestward, or 315 degrees at 11 kt. The
storm is expected to recurve between the western periphery of the
high and a trough located over the southeastern United States over
the next several days. Mostly because of an adjustment of
Gabrielle's initial position, the new NHC track forecast has been
adjusted a bit west of the previous prediction during the first 3
days of the forecast. That said, all of the reliable track models
continue to keep the core of Gabrielle well east of Bermuda Sunday
night and Monday during the recurvature. By Tuesday, global model
fields indicate that Gabrielle will become embedded in fast zonal
mid-latitude flow, and there has been a significant southward shift
in the track models on days 4 and 5. The NHC track forecast has
also been adjusted southward at those times, close to the HCCA and
Google DeepMind ensemble but not as far south as the GFS and many
of the multi-model consensus aids.

Vertical shear is expected to decrease over the next day or two,
which should allow Gabrielle's circulation to become more
vertically aligned, leading to strengthening. The intensity models
are generally split into two camps. The statistical-dynamical
models (SHIPS and LGEM) and global models (GFS and ECMWF) are more
subdued on the amount of strengthening that Gabrielle might
experience. The regional hurricane models, as well as the HCCA and
Florida State Superensemble, are more aggressive, with the HAFS
models in particular bringing Gabrielle to major hurricane strength
in about 2 days. While not going that high, the NHC intensity
forecast is close to the other models in that camp and continues to
show a possible peak of 90 kt in 60-72 hours. With the southward
shift in the track forecast at days 4 and 5, Gabrielle's
extratropical transition has likely been delayed, and the official
forecast continues to depict a tropical cyclone through the next 5
days.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should continue to monitor Gabrielle's forecasts since some wind
and rainfall impacts are still possible.

2. Swells generated by Gabrielle are beginning to reach Bermuda
and will build through the weekend. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 20/0900Z 24.3N 58.1W 45 KT 50 MPH
12H 20/1800Z 25.4N 59.3W 50 KT 60 MPH
24H 21/0600Z 27.0N 60.5W 60 KT 70 MPH
36H 21/1800Z 28.6N 61.6W 70 KT 80 MPH
48H 22/0600Z 30.3N 62.1W 80 KT 90 MPH
60H 22/1800Z 32.1N 61.3W 90 KT 105 MPH
72H 23/0600Z 34.0N 59.1W 90 KT 105 MPH
96H 24/0600Z 37.0N 50.6W 80 KT 90 MPH
120H 25/0600Z 38.7N 38.5W 65 KT 75 MPH

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 14
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sat Sep 20 2025

...RECON AIRCRAFT TO INVESTIGATE GABRIELLE TODAY...
...EXPECTED TO BECOME A HURRICANE AND PASS EAST OF BERMUDA SUNDAY
NIGHT AND MONDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...25.0N 59.0W
ABOUT 540 MI...865 KM NNE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 615 MI...990 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES





Tropical Storm Gabrielle Discussion Number 14
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sat Sep 20 2025

Gabrielle has become a little better organized this morning, with
increased curved banding over the eastern semicircle and a 1009Z
SSM/IS overpass suggesting a mid-level eye was forming. However,
this feature appeared to be to the northeast of the low-level
center, suggesting that Gabrielle is tilted vertically due to
southwesterly shear. Satellite intensity estimates have increased a
bit and are now in the 45-55 kt range. Based on this, the initial
intensity is increased to 50 kt. Air Force Reserve and NOAA
Hurricane Hunter aircraft are currently enroute to investigate
Gabrielle.

The initial motion is 320/11 kt. During the next 48-60 h,
Gabrielle is expected to recurve to the north and northeast between
the subtropical ridge to the east and a mid-latitude trough over
the southeastern United States and adjacent parts of the Atlantic.
The track guidance remains tightly clustered during this time, and
the main change since the last advisory is that the guidance is a
little slower in forward speed. Thus, this part of the new forecast
track is similar to, but a little slower than, the previous
forecast. The reliable guidance models and the official forecast
continue to keep Gabrielle well to the east of Bermuda during
recurvature. After 60 h, Gabrielle should move east-northeastward
to eastward as it becomes embedded in zonal westerly flow. This part
of the track guidance has shifted a little south from the previous
advisory and also shows a slower forward speed. The new official
forecast is therefore a little south of and a little slower than the
previous forecast.

Gabrielle is expected to be in a light-to-moderate shear
environment for the next 60-72 h, and steady strengthening is
expected during this time. One change in the intensity guidance
since the last advisory is that the regional hurricane models are
less aggressive in strengthening the storm, and so the forecast
peak intensity of 90 kt is now near the upper edge of the intensity
guidance envelope. After peak intensity, it currently appears that
Gabrielle's extratropical transition will not occur until after
the forecast period. So, the intensity forecast shows steady
weakening due to increasing westerly shear and decreasing sea
surface temperatures along the forecast track. The new intensity
forecast has some minor adjustments from the previous forecast.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. Interests on Bermuda
should continue to monitor Gabrielle's forecasts since some wind
and rainfall impacts are still possible.

2. Swells generated by Gabrielle are beginning to reach Bermuda
and will build through the weekend. These swells are also expected
to reach the coast of the United States from North Carolina
northward, along with the coast of Atlantic Canada, late this
weekend into early next week. These swells are likely to cause
life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 25.0N 59.0W 50 KT 60 MPH
12H 21/0000Z 26.2N 60.0W 55 KT 65 MPH
24H 21/1200Z 27.8N 61.2W 65 KT 75 MPH
36H 22/0000Z 29.4N 62.0W 75 KT 85 MPH
48H 22/1200Z 31.1N 61.9W 85 KT 100 MPH
60H 23/0000Z 32.8N 60.4W 90 KT 105 MPH
72H 23/1200Z 34.5N 57.7W 90 KT 105 MPH
96H 24/1200Z 37.0N 48.4W 80 KT 90 MPH
120H 25/1200Z 38.5N 36.5W 65 KT 75 MPH

$$
Forecaster Beven

[cycloneye]

Tropical Storm Gabrielle Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL072025
200 PM AST Sat Sep 20 2025


...HURRICANE HUNTER AIRCRAFT REPORT THAT GABRIELLE IS FARTHER EAST
AND A LITTLE STRONGER THAN INDICATED IN THE PREVIOUS ADVISORY...

Reports from NOAA and Air Force Reserve hurricane hunter aircraft
data show that the center of Gabrielle is located about 30 miles
farther east than indicated in the previous advisory. The maximum
sustained winds have increased to near 65 mph (105 km/h). The next
full advisory will be issued at 500 PM AST (2100 UTC).

SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
---------------------------------------------------
LOCATION...25.2N 58.7W
ABOUT 595 MI...960 KM NNE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 615 MI...990 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...105 KM/H
PRESENT MOVEMENT...NW OR 325 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.41 INCHES

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 15
NWS National Hurricane Center Miami FL AL072025
500 PM AST Sat Sep 20 2025

...GABRIELLE EXPECTED TO BECOME A HURRICANE TONIGHT OR ON
SUNDAY...
...EXPECTED TO PASS EAST OF BERMUDA SUNDAY NIGHT OR MONDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...25.6N 59.0W
ABOUT 575 MI...925 KM NNE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 580 MI...935 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES




Tropical Storm Gabrielle Discussion Number 15
NWS National Hurricane Center Miami FL AL072025
500 PM AST Sat Sep 20 2025

At about the time of the last advisory, an small eye-like feature
appeared in Gabrielle's central dense overcast. An NOAA Hurricane
Hunter aircraft then confirmed the presence of a 6 n mi wide eye
with a well-defined inner wind core. After that, a combination of
flight-level and dropsonde data from both NOAA and AF Reserve
aircraft showed maximum winds near 55 kt with a central pressure
near 996 mb. One note is that the aircraft flight-level wind data
suggests an outer wind maximum is forming around the small eye,
which coincides with convective bands seen in NOAA aircraft radar
data.

The aircraft found that the center of Gabrielle was about 30 n mi
east of the previous forecast track, and using the revised position
yields a 12-h motion of 325/9. Other than the center re-location,
there is little change to the track forecast philosophy. During
the next 48 h or so, Gabrielle is expected to recurve to the north
and northeast between the subtropical ridge to the east and a
mid-latitude trough over the southeastern United States and
adjacent parts of the Atlantic. While the track guidance for this
part of the forecast remains tightly clustered, the guidance has
shifted to the east based on the initial position, and it is also
showing a slower forward speed. So, the official forecast is also
nudged to the east and slowed down. With this change, the reliable
guidance models and the official forecast continue to keep
Gabrielle well to the east of Bermuda during recurvature. After
recurvature, Gabrielle should move east-northeastward to eastward
as it becomes embedded in zonal westerly flow. This part of the
track guidance has again shifted south from the previous advisory
and also shows a slower forward speed, with the new official
forecast adjusted accordingly.

Gabrielle is expected to be in a light-to-moderate shear
environment for the next 48 h or so, and steady strengthening is
expected during this time. After being less aggressive on the 06Z
runs, the 12Z runs of the regional hurricane models have trended
stronger. The new intensity forecast keeps a peak intensity of 90
kt, which is above the intensity consensus but below the regional
models. After peak intensity, it again appears that Gabrielle's
extratropical transition will not occur until after the end
of the forecast period. So, the intensity forecast shows steady
weakening due to increasing westerly shear and decreasing sea
surface temperatures along the forecast track. The new intensity
forecast again has some minor adjustments from the previous
forecast.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. While the chances of
impacts are decreasing, interests on Bermuda should continue to
monitor Gabrielle's forecasts since some wind and rainfall impacts
are still possible.

2. Swells generated by Gabrielle are beginning to reach Bermuda
and will build through the weekend. These swells are also expected
to reach the coast of the United States from North Carolina
northward, along with the coast of Atlantic Canada, late this
weekend into early next week. These swells are likely to cause
life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 20/2100Z 25.6N 59.0W 55 KT 65 MPH
12H 21/0600Z 26.7N 60.0W 65 KT 75 MPH
24H 21/1800Z 28.4N 61.1W 75 KT 85 MPH
36H 22/0600Z 29.9N 61.5W 85 KT 100 MPH
48H 22/1800Z 31.6N 60.8W 90 KT 105 MPH
60H 23/0600Z 33.3N 58.9W 90 KT 105 MPH
72H 23/1800Z 34.8N 55.8W 85 KT 100 MPH
96H 24/1800Z 36.6N 46.2W 70 KT 80 MPH
120H 25/1800Z 38.6N 33.8W 60 KT 70 MPH

$$
Forecaster Beven

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 16
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Sat Sep 20 2025

...GABRIELLE EXPECTED TO BECOME A HURRICANE ON SUNDAY...
...FORECAST TO PASS EAST OF BERMUDA ON MONDAY...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...26.3N 59.2W
ABOUT 535 MI...860 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES




Tropical Storm Gabrielle Discussion Number 16
NWS National Hurricane Center Miami FL AL072025
1100 PM AST Sat Sep 20 2025

Recent GMI and SSMIS passive microwave images of Gabrielle suggest
the tight inner core noted in earlier aircraft data has collapsed. A
larger mid-level eye structure now wraps over halfway around the
circulation but is open to the southwest. The low-level center of
the storm lies near the sharp western edge of the convective cloud
mass, which suggests Gabrielle is still contending with some shear.
Convective band wraps around the eastern side of the storm, where
recent ASCAT-B data confirm the strongest surface winds are
occurring. The initial intensity is set at 55 kt based on TAFB
Dvorak and UW-CIMSS objective satellite intensity estimates. Air
Force Reserve Hurricane Hunters are scheduled to investigate the
storm tomorrow morning.

Gabrielle is moving north-northwestward (335/8 kt) along the
southwestern side of a subtropical ridge over the central Atlantic.
Over the next couple of days, Gabrielle is expected to recurve to
the north and northeast between this ridge and a mid-latitude trough
over the eastern United States. The track models remain in good
near-term agreement, and the updated NHC track forecast keeps
Gabrielle well east of Bermuda on Monday. Then, Gabrielle is
forecast to accelerate east-northeastward through the rest of the
week while embedded in zonal westerly flow. There are greater speed
differences in the track models during the latter half of the
forecast period, but the consensus has trended slower once again,
and this is reflected in the updated NHC forecast.

Assuming Gabrielle is able to solidify its inner core soon, some
strengthening is expected over warm waters within a low to moderate
shear environment during the next couple of days. The latest track
guidance is not quite as aggressive as earlier today. The NHC
forecast is very similar to the previous one, remaining close to the
HFIP corrected consensus (HCCA) near the higher end of the guidance
envelope. By Tuesday, increased westerly shear is forecast to cause
Gabrielle to weaken, especially while it moves over cooler waters
later next week. The long-range forecast track uncertainty makes it
difficult to assess whether Gabrielle will fully complete
extratropical transition by the end of the period. However, it seems
likely that the system will be losing tropical characteristics and
in close proximity to fronts by Friday.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane on Sunday and pass
east of Bermuda on Monday. While the chances of impacts are
decreasing, interests on Bermuda should continue to monitor forecast
updates since some wind and rainfall impacts are still possible.

2. Swells generated by Gabrielle will continue to affect Bermuda
through early next week. These swells are expected to reach the
coast of the United States from North Carolina northward, along with
the coast of Atlantic Canada, on Sunday and continue through early
next week. These swells are likely to cause life-threatening surf
and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 21/0300Z 26.3N 59.2W 55 KT 65 MPH
12H 21/1200Z 27.4N 60.3W 65 KT 75 MPH
24H 22/0000Z 29.1N 61.3W 75 KT 85 MPH
36H 22/1200Z 30.7N 61.5W 85 KT 100 MPH
48H 23/0000Z 32.3N 60.5W 90 KT 105 MPH
60H 23/1200Z 33.8N 58.2W 85 KT 100 MPH
72H 24/0000Z 35.1N 54.5W 80 KT 90 MPH
96H 25/0000Z 36.5N 44.0W 65 KT 75 MPH
120H 26/0000Z 39.0N 31.5W 60 KT 70 MPH

$$
Forecaster Reinhart

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 17
NWS National Hurricane Center Miami FL AL072025
500 AM AST Sun Sep 21 2025

...GABRIELLE EXPECTED TO BECOME A HURRICANE TODAY...

SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...27.2N 60.0W
ABOUT 455 MI...730 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES





Tropical Storm Gabrielle Discussion Number 17
NWS National Hurricane Center Miami FL AL072025
500 AM AST Sun Sep 21 2025

Gabrielle has become slightly better organized overnight. The large
convective band over the eastern side of the system has persisted,
and within the last few hours deep convection has been bursting over
the low-level center. There have been no microwave passes since the
previous advisory, to determine if the inner core has been able to
close off on the southwestern side. Satellite intensity estimates
from TAFB and SAB were both T/3.5 or 55 kts. Latest objective AiDT,
DPRINT, and DMINT intensity estimates from UW-CIMSS range from 52 to
58 kt. Using these estimates, the intensity is held at 55 kt for
this advisory, although that could be conservative given recent
convective burst. An Air Force Reserve Hurricane Hunter aircraft is
en route to investigate the storm and will provide important details
on the intensity and structure of the system.

The storm is moving north-northwestward at an estimated motion of
335/8 kt. The system continues to be steered by a subtropical ridge
over the Central Atlantic. Over the next few days, Gabrielle will
begin to recurve to the north and eventually northeast between the
western periphery of the ridge and a trough moving offshore the east
coast of the United States. Track models remain tightly clustered
and keep Gabrielle well east of Bermuda on Monday. As Gabrielle
becomes steered within the west-southwesterly wind flow, the system
will accelerate across the Atlantic. By day 3 of the forecast
period, there is some along track model spread with differences in
the forward speed of the system. The NHC track forecast is near the
previous in the short term, but some minor adjustments to slow down
the previous forecast towards the consensus aids were made between
day 3-5.

The environment surrounding the system is favorable for
strengthening over the next couple of days, with light to moderate
wind shear, warm sea surface temperatures, and slightly better
mid-level relative humidity values. As Gabrielle looks to be
establishing an inner core, it should begin to strengthen. The NHC
intensity forecast follows these trends although the intensity
guidance has continued to trend not as aggressive due to how long
the system has taken to establish an inner core, and the peak
intensity forecast has been lowered to 85 kt, which remains near the
higher end of the guidance envelope. In about 48 h, westerly shear
will begin to increase and sea surface temperatures will begin to
cool along the forecast track, thus a weakening trend is forecast.
The long-range forecast along track uncertainty makes it difficult
to assess whether Gabrielle will fully complete extratropical
transition by the end of the period.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane later today and pass
east of Bermuda on Monday. While the chances of impacts are
decreasing, interests on Bermuda should continue to monitor forecast
updates since some wind and rainfall impacts are still possible.

2. Swells generated by Gabrielle will continue to affect Bermuda
during the next few days. These swells are expected to reach the
east coast of the United States from North Carolina northward, as
well as Atlantic Canada, beginning later today and continuing
through early this week. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 21/0900Z 27.2N 60.0W 55 KT 65 MPH
12H 21/1800Z 28.3N 60.9W 65 KT 75 MPH
24H 22/0600Z 29.9N 61.6W 75 KT 85 MPH
36H 22/1800Z 31.5N 61.3W 80 KT 90 MPH
48H 23/0600Z 33.1N 59.7W 85 KT 100 MPH
60H 23/1800Z 34.5N 56.8W 80 KT 90 MPH
72H 24/0600Z 35.4N 52.9W 70 KT 80 MPH
96H 25/0600Z 36.9N 41.7W 60 KT 70 MPH
120H 26/0600Z 40.0N 29.0W 55 KT 65 MPH

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 18
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sun Sep 21 2025

...GABRIELLE POISED TO BECOME A HURRICANE LATER TODAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...27.7N 61.0W
ABOUT 390 MI...630 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES




Tropical Storm Gabrielle Discussion Number 18
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sun Sep 21 2025

Structurally, Gabrielle continues to become better organized, with
cold convective cloud tops now finally starting to wrap around the
circulation of the storm. In fact, earlier this morning, a WSF-M
microwave pass revealed a cyan ring on the 37-GHz channel, which was
supported by the most recent Air Force Reserve reconnaissance
mission, which did indicate an eyewall, albeit still open to the
east-southeast. Unfortunately the plane wasn't able to complete a
full pattern, and its possible the highest flight-level winds
haven't been sampled in the northeastern quadrant. For now the
intensity will be held at 55 kt, in good agreement with the 12 UTC
subjective Dvorak fix from TAFB and latest D-PRINT estimate from
UW-CIMSS.

The earlier recon flight found the center a little further west of
the prior forecast track, but the estimated motion still remains
northwestward at 320/10 kt. Gabrielle is rounding the western
periphery of a subtropical ridge centered to its east, and thus
should continue to turn northward and ultimately northeastward over
the next 24-48 hours. In addition to a slight westward shift due to
the initial position, the guidance has shifted a little slower
again this cycle, and the NHC forecast track was nudged in that
direction. However, this latest track still keeps Gabrielle well to
the east of Bermuda when it passes its latitude in about 36 hours.
Thereafter, the cyclone should begin to gradually accelerate in the
westerly flow around the north side of the aforementioned ridge,
and should ultimately be picked up by another mid-latitude trough
digging into the central subtropical Atlantic in about 4-5 days.
The latter portion of the NHC track forecast has been little
changed, blending the reliable HCCA and Google Deep Mind (GDMI)
aids.

While the morning Air Force mission found that Gabrielle was still a
bit tilted with height, recent satellite images suggest the low and
mid-level centers are becoming better aligned as I write this
passage. In addition, environmental conditions remain quite
favorable in the short-term. While the SHIPS rapid intensification
indices are not especially high, they are 2 times above climatology,
and DTOPS is higher showing a 26-43 percent chance of a 25 to 30 kt
increase in intensity over the next 24 h. Both HAFS-A/B are
explicitly forecasting rapid intensification over the next 24 hours,
and given the improving inner core structure, this seems like a
reasonable prediction. Thus, the NHC intensity forecast will now
forecast rapid intensification over the next 24 h, and peaking
Gabrielle as a 95 kt hurricane in 36 h. This value is on the high
side of the intensity guidance, but not as high as the latest
HAFS-A/B runs which both show it becoming a major hurricane in 36
hours, and that remains a possibility. Thereafter, vertical wind
shear out of the southwest markedly increases, and there is also dry
air lurking in that region that will likely disrupt Gabrielle's
core, leading to weakening through the remainder of the forecast
period. Gabrielle may be close to becoming extratropical at the end
of the forecast as it begins to phase with an deep-layer trough
forecast to be picking it up from the west. However, that appears to
complete just beyond the forecast period.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane soon and pass east
of Bermuda on Monday. While the chances of impacts are decreasing,
interests on Bermuda should continue to monitor forecast updates
since some wind and rainfall impacts are still possible.

2. Swells generated by Gabrielle will continue to affect Bermuda
during the next few days. These swells are expected to reach the
east coast of the United States from North Carolina northward, as
well as Atlantic Canada, starting today and continuing through early
this week. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 27.7N 61.0W 55 KT 65 MPH
12H 22/0000Z 28.8N 61.8W 70 KT 80 MPH
24H 22/1200Z 30.3N 62.0W 85 KT 100 MPH
36H 23/0000Z 31.9N 61.3W 95 KT 110 MPH
48H 23/1200Z 33.3N 59.2W 90 KT 105 MPH
60H 24/0000Z 34.8N 55.5W 80 KT 90 MPH
72H 24/1200Z 35.6N 50.5W 70 KT 80 MPH
96H 25/1200Z 36.9N 38.4W 65 KT 75 MPH
120H 26/1200Z 41.0N 27.1W 60 KT 70 MPH

$$
Forecaster Papin

[cycloneye]

BULLETIN
Tropical Storm Gabrielle Advisory Number 18
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sun Sep 21 2025

...GABRIELLE POISED TO BECOME A HURRICANE LATER TODAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...27.7N 61.0W
ABOUT 390 MI...630 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES




Tropical Storm Gabrielle Discussion Number 18
NWS National Hurricane Center Miami FL AL072025
1100 AM AST Sun Sep 21 2025

Structurally, Gabrielle continues to become better organized, with
cold convective cloud tops now finally starting to wrap around the
circulation of the storm. In fact, earlier this morning, a WSF-M
microwave pass revealed a cyan ring on the 37-GHz channel, which was
supported by the most recent Air Force Reserve reconnaissance
mission, which did indicate an eyewall, albeit still open to the
east-southeast. Unfortunately the plane wasn't able to complete a
full pattern, and its possible the highest flight-level winds
haven't been sampled in the northeastern quadrant. For now the
intensity will be held at 55 kt, in good agreement with the 12 UTC
subjective Dvorak fix from TAFB and latest D-PRINT estimate from
UW-CIMSS.

The earlier recon flight found the center a little further west of
the prior forecast track, but the estimated motion still remains
northwestward at 320/10 kt. Gabrielle is rounding the western
periphery of a subtropical ridge centered to its east, and thus
should continue to turn northward and ultimately northeastward over
the next 24-48 hours. In addition to a slight westward shift due to
the initial position, the guidance has shifted a little slower
again this cycle, and the NHC forecast track was nudged in that
direction. However, this latest track still keeps Gabrielle well to
the east of Bermuda when it passes its latitude in about 36 hours.
Thereafter, the cyclone should begin to gradually accelerate in the
westerly flow around the north side of the aforementioned ridge,
and should ultimately be picked up by another mid-latitude trough
digging into the central subtropical Atlantic in about 4-5 days.
The latter portion of the NHC track forecast has been little
changed, blending the reliable HCCA and Google Deep Mind (GDMI)
aids.

While the morning Air Force mission found that Gabrielle was still a
bit tilted with height, recent satellite images suggest the low and
mid-level centers are becoming better aligned as I write this
passage. In addition, environmental conditions remain quite
favorable in the short-term. While the SHIPS rapid intensification
indices are not especially high, they are 2 times above climatology,
and DTOPS is higher showing a 26-43 percent chance of a 25 to 30 kt
increase in intensity over the next 24 h. Both HAFS-A/B are
explicitly forecasting rapid intensification over the next 24 hours,
and given the improving inner core structure, this seems like a
reasonable prediction. Thus, the NHC intensity forecast will now
forecast rapid intensification over the next 24 h, and peaking
Gabrielle as a 95 kt hurricane in 36 h. This value is on the high
side of the intensity guidance, but not as high as the latest
HAFS-A/B runs which both show it becoming a major hurricane in 36
hours, and that remains a possibility. Thereafter, vertical wind
shear out of the southwest markedly increases, and there is also dry
air lurking in that region that will likely disrupt Gabrielle's
core, leading to weakening through the remainder of the forecast
period. Gabrielle may be close to becoming extratropical at the end
of the forecast as it begins to phase with an deep-layer trough
forecast to be picking it up from the west. However, that appears to
complete just beyond the forecast period.


KEY MESSAGES:

1. Gabrielle is forecast to become a hurricane soon and pass east
of Bermuda on Monday. While the chances of impacts are decreasing,
interests on Bermuda should continue to monitor forecast updates
since some wind and rainfall impacts are still possible.

2. Swells generated by Gabrielle will continue to affect Bermuda
during the next few days. These swells are expected to reach the
east coast of the United States from North Carolina northward, as
well as Atlantic Canada, starting today and continuing through early
this week. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 27.7N 61.0W 55 KT 65 MPH
12H 22/0000Z 28.8N 61.8W 70 KT 80 MPH
24H 22/1200Z 30.3N 62.0W 85 KT 100 MPH
36H 23/0000Z 31.9N 61.3W 95 KT 110 MPH
48H 23/1200Z 33.3N 59.2W 90 KT 105 MPH
60H 24/0000Z 34.8N 55.5W 80 KT 90 MPH
72H 24/1200Z 35.6N 50.5W 70 KT 80 MPH
96H 25/1200Z 36.9N 38.4W 65 KT 75 MPH
120H 26/1200Z 41.0N 27.1W 60 KT 70 MPH

$$
Forecaster Papin