[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281008
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Oct 28 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...

Tropical Storm Tammy is centered near 33.0N 60.1W at 28/0900 UTC
or 240 nm E of Bermuda, moving NE at 6 kt. Estimated minimum
central pressure is 994 mb. Maximum sustained wind speed is 45
kt with gusts to 55 kt. Peak seas are 21 ft. Scattered moderate
convection prevails over the NE quadrant. On the forecast track,
Tammy will continue to move away from Bermuda today. Weakening
is expected during the next few days, and Tammy is forecast to
become a post-tropical remnant low early next week. Swells
generated by Tammy will continue to affect Bermuda through
tonight. These swells are likely to cause life- threatening surf
and rip current conditions. Please consult products from your
local weather office for details.

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.

Western Atlantic Rough Seas: A subtropical ridge over the
Carolinas combines with a low level trough than extends from S of
Tammy to the NE Caribbean to produce a large area of fresh to
strong winds and very high seas between Tammy and the Bahamas. A
large area of 12-13 ft seas is just northeast of the Bahamas and
the Turks and Caicos Islands. These associated high seas between
Tammy and the Bahamas will subside through Sun, decreasing below 8
ft by late Mon. Mariners should either avoid this region or use
extreme caution in this area, depending on your vessel type and
cargo. Hazardous surf and rip currents are also anticipated along
the coast of central Florida, the Bahamas, Greater Antilles and
the northern Leeward Islands.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at the website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the Offshore
Waters Forecast at https://www.nhc.noaa.gov/marine/offshores.php
for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Senegal near 14N17W and continues southwestward to 13N19W. The
ITCZ extends from 13N19W to 08N53W. Scattered moderate to
isolated strong convection prevails from 04N to 12N and between
30W and 47W.

The eastern North Pacific monsoon trough extends from Central
America along the southern coast of Nicaragua at 11N84W to a 1007
mb low pressure near 11N81W to the coast of Colombia at 12N72W.
Scattered moderate convection is noted south of 13N and between
73W and 84W.

...GULF OF MEXICO...

A 1023 mb high pressure over the Carolinas extends southwestward
into the Gulf of Mexico. A dry airmass prevails across the Gulf
waters. Fresh to strong easterly winds are noted in latest
scatterometer data south of 25N and east of 95W. Seas in these
waters are 6-8 ft, with the highest seas occurring in the eastern
Bay of Campeche. Moderate or weaker winds and 4-6 ft seas prevail
elsewhere.

For the forecast, high pressure centered across the middle Atlantic
coastal states will continue to support fresh to strong winds in
the southeast and south central Gulf through early Sun. Gentle NE
winds are expected by Mon as the pressure gradient weakens and
high pressure settles over the region. The next cold front is
forecast to reach the NW Gulf on Mon. This front will bring gale
force winds and quickly building seas over the western Gulf
beginning Mon evening. The front will move SE through the entire
basin by late Wed.

...CARIBBEAN SEA...

A surface trough is analyzed from the Mona Passage to northern
Venezuela. Meanwhile, an active upper level trough stretches from
the Windward Passage to Central America. These features combined
with plenty of tropical moisture result in numerous showers and
isolated thunderstorms east of the surface trough, affecting
Puerto Rico and the Virgin Islands with very heavy rainfall. Flash
flooding is already occurring in Puerto Rico. The weather pattern
will remain very conducive for the development of showers and
thunderstorms across the region during the weekend and into early
next week.

The remainder of the Caribbean is under the influence of the
1023 mb high pressure system over the Carolinas. No deep
convection is noted in the NW Caribbean Sea and most of the
central portion of the basin. The pressure gradient between the
aforementioned ridge and lower pressures in the deep tropics
support fresh to strong NE winds north of 16N and west of 75W.
The strongest winds are found in the lee of Cuba. Seas in these
waters are 5-8 ft. Fresh to strong southerly winds and seas to 7 ft
are evident in the eastern Caribbean near convection. A large
region of northerly swell associated with Tammy reaches the NE
Caribbean waters including the Passages. Moderate or weaker winds
and wave heights in the 3-5 ft range are present in the rest of
the Caribbean.

For the forecast, strong high pressure centered over the middle
Atlantic U.S. coast is combining with elongated low pressure
extending from the W central Atlantic across the NE Caribbean will
support fresh to strong NE to E winds in the NW Caribbean,
through this morning. Gentle winds prevail elsewhere. Large N-NE
swell across the W Atlantic will continue to move through the NE
Caribbean Passages through Sun. Broad low pressure is expected to
develop over the W central Caribbean by Sun and move slowly
northward and into the Bahamas through Tue.

...ATLANTIC OCEAN...

Please read the Special Features section above for more
information on Tropical Storm Tammy east of Bermuda, and rough
seas across the SW North Atlantic.

The central and eastern tropical Atlantic are under the influence
of a subtropical ridge anchored by a 1020 mb high near 29N42W.
The pressure gradient between this ridge and lower pressures in
the deep tropics result in fresh to strong easterly winds south
of 22N, along with seas of 6-8 ft. Farther east, a broad storm
system west of Ireland is producing a large region of swell that
is entering the northeast waters of the tropical Atlantic,
resulting in seas of 8-11 ft north of the Canary Islands and east
of 22W. Elsewhere, moderate or weaker winds and moderate seas are
prevalent.

For the forecast W of 55W, Tropical Storm Tammy will move to
33.0N 58.7W this afternoon, 32.6N 56.0W Sun morning, 31.7N 53.1W
Sun afternoon, weaken to a remnant low near 30.4N 50.6W Mon
morning, 28.9N 49.5W Mon afternoon, and 27.5N 50.8W Tue morning.
Tammy will change little in intensity as it moves to 27.9N 53.1W
by early Wed. High pressure across the middle Atlantic coastal
states is combining with a low level trough than extends from S of
Tammy to the NE Caribbean to produce a large area of fresh to
strong winds, with very high seas between Tammy and the Bahamas.
These high seas will slowly subside through Sun. Elongated low
pressure will develop across the SE Bahamas Sun and gradually
drift NW through Tue.

$$
ERA
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