[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291039
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Oct 29 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

Post-Tropical Cyclone Tammy is centered near 32.4N 53.3W at
29/0900 UTC or 580 nm E of Bermuda, moving E at 16 kt. Estimated
minimum central pressure is 1002 mb. Maximum sustained wind
speed is 35 kt with gusts to 45 kt. Peak seas are 16 ft. Strong
westerly shear is displacing the convection well east of the
center. Gradual weakening is expected during the next couple of
days as the system moves S.

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

Invest 96L: A 1007 mb low pressure is near 22N68.5W. Scattered
moderate to isolated strong convection is noted from 17N to 27N
between 63W and 68W. The system is producing strong to near gale-
force winds, especially over the northern semicircle. Seas in the
area are 8-12 ft. The disturbance is showing signs of organization
and a short-lived tropical depression or storm could form later
today while the system moves west-northwestward. By Monday,
however, strong upper-level winds and dry air should end the
chances of further development. The chance of development over
the next 48 hours is high. Please read the latest Tropical
Weather Outlook at hurricanes.gov for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the tropical Atlantic near 14N16W and
continues southwestward to 07N23W. The ITCZ stretches from 07N23W
to 09N57W. Scattered moderate convection is noted from 04N to 08N
between 21W and 36W, and from 06N to 14N between 41W and 54W.

GULF OF MEXICO...

The subtropical ridge off the SE United States continues to
dominate the weather conditions across the Gulf of Mexico,
suppressing the development of deep convection. A modest pressure
gradient between the aforementioned high pressure system and
lower pressures in the deep tropics support fresh to strong
easterly winds, mainly south of 27N and east of 93W. Seas are 5-9
ft in these waters. The strongest winds and highest seas are
occurring in the Florida Straits. Moderate or weaker winds and
seas of 2-5 ft are present elsewhere.

For the forecast, the high pressure will continue to support
fresh to locally strong winds in the southeast and south central
Gulf through today. Gentle NE winds are expected by Mon as the
pressure gradient weakens and high pressure settles over the
region. A strong cold front will enter the NW Gulf Mon morning,
and move SE across the entire basin by Wed evening. This front
will bring gale force winds and quickly building seas over the
western Gulf beginning Mon thru Wed night.

CARIBBEAN SEA...

The eastern Pacific monsoon trough extends from the coast of
Nicaragua to the central Caribbean. A surface trough extends along
69W and N of 16N. The cyclonic flow brings plenty of moisture
northward, and along with divergence aloft, result in unsettled
weather conditions to the east of the surface features described.
Latest satellite imagery show scattered showers and isolated
thunderstorms affecting the waters offshore Colombia, Puerto Rico
and the Leeward Islands. These storms are also impacting the
islands in the NE Caribbean, causing localized flooding. This
weather pattern will continue through early next week.

Dry air encompasses the NW Caribbean and Gulf of Honduras,
resulting in only fast-moving, isolated light showers. The
pressure gradient between the ridge off the SE United States and
lower pressures in the deep tropics sustain fresh to strong NE-E
winds in the NW Caribbean, Gulf of Honduras and Windward Passage.
Seas are 4-7 ft in the areas described. The strongest winds are
occurring in the lee of Cuba. Moderate to locally fresh southerly
winds and seas of 4-7 ft are found in the eastern Caribbean.
Elsewhere, light to gentle winds and slight to moderate seas
prevail.

For the forecast, the fresh to locally strong NE to E winds in
the NW Caribbean will subside today. The surface trough along 69W
will shift W-NW through early this week. Scattered to numerous
strong thunderstorms occurring along and E of the trough will
shift westward with the trough through Mon. Large N-NE swell
across the W Atlantic will continue to move through the NE
Caribbean Passages through today. A strong cold front will enter
the NW Caribbean by mid week.

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section above for information on
Post-tropical Cyclone Tammy located well east of Bermuda and on
Invest 96L positioned north of the Dominican Republic.

A 1021 mb high pressure system off the SE United States dominates
the SW tropical Atlantic. The pressure gradient between the ridge
and lower pressures in the deep tropics and Invest 96L sustain
fresh to strong NE winds west of 60W. Seas in these waters are
8-12 ft, with the highest seas occurring off the southern
Bahamas.

The central and eastern Atlantic are under the influence of a
1016 mb high pressure system near 26N39W. A cold front enters the
tropical Atlantic near 31N25W to 29N35W, then becomes stationary
to 31N39W. No deep convection is seen near the frontal boundary.
Moderate to locally fresh westerly winds and seas of 6-8 ft are
evident north of 30N and E of 32W. The pressure gradient between
the ridge and lower pressures in the deep tropics support moderate
to strong easterly winds south of 20N and west of 30W. Wave
heights in the area described are 8-9 ft. Farther east, moderate
to locally fresh northerly winds and seas of 6-8 ft are found off
the coast of Africa, mainly east of 22W. Elsewhere, moderate or
weaker winds and moderate seas prevail.

For the forecast W of 55W, Post-Tropical Cyclone Tammy will
become a remnant low and move to 31.6N 50.4W this afternoon, 30.1N
47.6W Mon morning, 28.5N 46.7W Mon afternoon, 27.2N 46.6W Tue
morning, 26.1N 48.0W Tue afternoon, and dissipate Wed morning.
High pressure across the middle Atlantic coastal states is
combining with a low level trough than extends from a 1007 mb low
pressure located just N of Dominican Republic to produce an area
of fresh to locally strong winds over the northern semicircle of
the low. A short-lived tropical depression or storm could form
later today while this system moves west- northwestward. By
Monday, however, strong upper-level winds and dry air should end
the chances of further development. A strong cold front will enter
the NW waters Wed.

$$
ERA
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