[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 250501
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Sep 25 2023

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0455 UTC.

...SPECIAL FEATURES...

Tropical Storm Philippe is near 17.1N 43.3W at 11 PM EDT, and is
moving west-northwest at 12 kt. Maximum sustained winds are 45 kt
with gusts to 55 kt, and the minimum central pressure is 1000 mb.
Peak seas near the center are up to 22 ft. Numerous moderate
scattered strong convection is noted within 270 nm across the
eastern semicircle and 75 nm across the western semicircle. A
continued west-northwest motion is expected for the next day or
two, with a gradual turn to the northwest anticipated by mid-
week. Little overall change in strength is forecast during the
next 2 to 3 days.

Please, read the latest HIGH SEAS FORECAST, that is
issued by the National Hurricane Center, at the website-
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the
latest Tropical Storm Philippe NHC Forecast/Advisory
and Public Advisory, at www.hurricanes.gov, for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave (Invest 91L) has its axis along
28W, south of 19N, moving westward at 10 kt. A 1010 mb low
pressure is along the wave axis near 09N28W. Scattered moderate to
isolated strong convection is observed from 03N to 14N and
between 25W and 37W. The environmental conditions are forecast to
be conducive for gradual development of this system, and a
tropical depression may form around midweek. This weather system
is forecast to move westward to west-northwestward in the central
tropical Atlantic Ocean. The disturbance has a medium chance of
development over the next 48 hours. For more information, please
read the Tropical Weather Outlook at hurricanes.gov

A central Caribbean tropical wave has its axis along 73W, south
of 21N, moving westward at 10-15 kt. No deep convection is noted
near the trough axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Senegal near 14N17W and continues southwestward to a 1010 mb low
pressure (AL91) near 09N28W and then to 07N36W. The ITCZ extends
from 13N47W to 10N61W. Scattered moderate convection is present
within 120 nm on both sides of the ITCZ.

...GULF OF MEXICO...

A broad surface trough extends from western Florida to the Yucatan
peninsula. Abundant tropical moisture and divergence aloft is
enhancing the development of scattered showers and thunderstorms
across the SE Gulf, especially off SW Florida and the Florida
Straits. Fairly tranquil weather conditions are found elsewhere in
the basin. The weak pressure gradient across the Gulf supports
moderate or weaker winds and seas of 3-5 ft north of 23N and 1-3
ft elsewhere.

For the forecast, a surface trough over the southeast Gulf
accompanied by scattered showers and thunderstorms will drift
slowly into the western Gulf through the early part of the week
and dissipate. Meanwhile, weak high pressure will persist over the
north-central and northeast Gulf. This pattern will support
gentle to moderate NE to E winds and slight seas across the basin
through the middle of the week.

...CARIBBEAN SEA...

Abundant tropical moisture and a favorable upper level pattern
continue to sustain scattered moderate to isolated strong
convection north of 19N and west of 75W. Scattered showers are
also noted in the eastern Atlantic, affecting the Lesser Antilles.
Isolated showers dot the remainder of the Caribbean Sea.

A building subtropical ridge over the central Atlantic and lower
pressures in northern South America support fresh to strong
easterly trade winds in the central Caribbean. A recent
scatterometer satellite pass captured the strongest winds
occurring off northern Colombia. Seas in these waters are 5-8 ft.
Moderate to fresh easterly breezes are found in the eastern
Caribbean Sea, along with seas of 3-6 ft. Elsewhere, light to
gentle winds and slight seas prevail.

For the forecast, high pressure north of the area will support
moderate to fresh trade winds across most of the eastern and
central Caribbean through the early part of the week, with fresh
to strong pulses off northwest Venezuela and northeast Colombia
during mainly the overnight and early morning hours into mid week.
Seas will build in mixed NE and E swell across the waters east of
the Leeward Islands starting Mon night, ahead of Tropical Storm
Philippe. Philippe is expected to turn NW before reaching 55W, and
move into the central Atlantic.

...ATLANTIC OCEAN...

Refer to the Special Features section for details on Tropical
Storm Philippe.

The storm activity described in the Gulf of Mexico section is also
generating a few showers and thunderstorms over the NW Bahamas.
Farther east, a surface trough between Bermuda and Hispaniola and
divergence aloft continue to produce isolated to scattered
moderate convection, especially north of 25N and between 58W and
65W.

The remainder of the Atlantic is dominated by an expansive
1026 mb subtropical ridge centered several hundred miles southwest
of the Azores. Moderate to locally fresh SE-S winds and moderate
seas are present west of 55W. Similarly, moderate to fresh NE
winds and seas of 5-8 ft are found off the coast of Africa, mainly
18N to 27N and east of 23W. Elsewhere, moderate or weaker winds
and moderate mixed seas are prevalent.

For the forecast west of 55W, Tropical Storm Philippe is well east
of the area over the central Atlantic near 17.1N 43.3W at 11 PM
EDT, and is moving west- northwest at 12 kt. Maximum sustained
winds are 45 kt with gusts to 55 kt, and the minimum central
pressure is 1000 mb. Philippe will continue to move west-
northwest for the next day or two, with a gradual turn to the
northwest anticipated by mid- week. Looking ahead, this path will
place the center of the storm near 21.6N 54.0W Wed evening and
23.4N 55.9W by late Thu and 25.5N 57.0W by late Fri. Regardless of
the exact position of the center later in the week, rough seas
ahead of the storm can be expected east of 60W starting late Tue.
Elsewhere, seas may build by Thu north of the Bahamas and east of
Florida in NE swell.

$$
DELGADO
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