[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260537
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Thu Oct 26 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
0545 UTC.

...SPECIAL FEATURES...

Hurricane Tammy is centered near 29.9N 57.8W at 26/0300 UTC or
390 nm ESE of Bermuda, moving NNE at 17 kt. Estimated minimum
central pressure is 973 mb. Maximum sustained wind speed is 80
kt with gusts to 100 kt. Peak seas near the center are estimated
at 32 ft. Scattered moderate to strong convection is within 370
nm E semicircle and 100 nm NW semicircle. A northward to
northwestward turn is expected overnight, followed by a slower
west-northwestward motion on Friday. Some weakening is expected
during the next few days. Tammy is forecast to become a powerful
post-tropical cyclone early today. Swell will continue to affect
portions of Bermuda, the northern Leeward Islands, the British
and U.S. Virgin Islands, and Puerto Rico during the next couple
of days. These swells are likely to cause life-threatening surf
and rip current conditions. 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 latest
Tammy NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Western Atlantic Very Rough Seas: A very tight pressure gradient
between strong high pressure of 1028 mb centered over the east
coast of North Carolina and Hurricane Tammy will continue to
support a large area of strong to near-gale force NE winds and
very rough seas of 12 to 18 ft across much of the area from 22N
to 31N, between the east coast of Florida and 60W, through
Friday. NOAA Buoy 41049 near 27.5N 63.0W has been reporting
significant wave heights of 15 to 22 ft continuously for the
past 24 hours, with the most recent observation 19 ft as of
26/0240 UTC. Recent wind speeds at this buoy are 25.3 kt gusting
to 33 kt. A recent satellite derived wind data confirmed the
presence of N to NE winds of 25 to 30 kt. Mariners should either
seek to avoid this region, or use extreme caution in this area,
depending on your vessel type and cargo. Please read the latest
HIGH SEAS FORECAST issued by the National Hurricane Center at
the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for
more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Guinea near 11N15.5W, then continues westward to near
06.5N33.5W. The ITCZ extends from 06.5N33.5W to 08.5N46W, then
continues west of a surface trough from 09N51W to 12N60W. The
surface trough extends from 07N49W to 14N47W. Scattered moderate
convection is noted from 02N to 16N east of 34W, from 10N to 16N
between 42W and 49W, and from 10N to 12N between 54W and 62W.

...GULF OF MEXICO...

A strong high pressure of 1028 mb centered over the east coast of
North Carolina extends a broad ridge across the Gulf of Mexico
bringing mostly dry conditions. Fresh east to southeast winds
and 6 to 9 ft seas prevail across the Gulf. The strongest winds
and roughest seas are in the E and SE Gulf and Straits of
Florida, with fresh to strong winds and seas of 7 to 9 ft.

For the forecast, the aforementioned high pressure north of the
area will support moderate to fresh winds, locally strong in the
E Gulf, through the remainder of the week. Mainly gentle NE
winds are expected this weekend as the pressure gradient weakens
and high pressure settles over the region.

...CARIBBEAN SEA...

Divergence aloft is leading scattered showers and thunderstorms
across the central and eastern Caribbean Sea from 14N to 19N
between 65W and 80W, including portions of Jamaica, southern
Hispaniola, and Puerto Rico. Isolated moderate convection is
noted along the N coast of Honduras into the southern Gulf of
Honduras. Scattered moderate to strong convection is along the N
coast of NW Venezuela and NE Colombia. Scattered moderate
convection is also noted in the SW Caribbean, off the coast of
Costa Rica and Nicaragua.

Strong high pressure over the east coast of North Carolina is
leading to a very strong fetch of NE winds and rough seas over
the Atlantic, to the north of the Caribbean Sea. To an extent,
these conditions are affecting the northern Caribbean, north of
15.5N and west of 67W, where fresh to locally strong NE winds
and 5 to 7 ft seas prevail, including in the Mona and Windward
Passages, as well as south of Cuba and across the NW Caribbean.
To the south of 16N, gentle or lighter trades and 1 to 3 ft seas
prevail.

For the forecast, fresh to occasionally strong winds will
prevail in the NW and north-central Caribbean through the week.
Gentle winds will prevail elsewhere.

...ATLANTIC OCEAN...

Please read the Special Features section at the beginning about
Hurricane Tammy as well as rough seas that are occurring over
most of the western Atlantic to the W of Hurricane Tammy,
extending to the coast of Florida and the Straits of Florida.

Aside from the impacts from these two features, to the E of 50W,
high pressure of 1024 mb centered south of the Azores near 32N29W
is dominant. Gentle to moderate winds prevail across the basin
between 25W and 50W with seas 5 to 7 ft. Fresh NE winds are
occurring offshore Africa between the Cabo Verde and Canary
Islands.

For the forecast W of 55W, Hurricane Tammy is near 29.9N 57.8W
at 11 PM EDT, and is moving north-northeast at 17 kt. Maximum
sustained winds are 80 kt with gusts to 100 kt, and the minimum
central pressure is 973 mb. Tammy will become extratropical and
move to 30.7N 58.6W Thu morning, be near 31.3N 59.8W Thu
evening, and 31.6N 60.8W Fri morning. Tammy will reach 31.9N
62.0W Fri evening, 32.1N 61.7W Sat morning, and 32.2N 61.0W Sat
evening. Tammy will change little in intensity as it moves E of
Bermuda late Sun. A stationary front from 31N57W to the SE
Bahamas will dissipate overnight, but the gradient between Tammy
and the decaying front combined with high pressure building N of
the area will support a broad area of strong to near gale NE
winds and rough seas across much of the area this week, mainly W
of where the frontal boundary currently resides.

$$
KRV
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