[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211714
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Oct 21 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

Hurricane Tammy is centered near 16.0N 60.7W at 21/1500 UTC or
40 nm ESE of Guadeloupe, moving NW at 7 kt. Estimated minimum
central pressure is 988 mb. Maximum sustained wind speed is 75
kt with gusts to 90 kt. Peak seas are 24 ft. Scattered moderate
isolated strong convection is from 11N to 18N between 58W and 61W. A
turn toward the north-northwest is forecast on Sunday, followed
by a turn toward the north on Monday. On the forecast track, the
center of Tammy will move near or over portions of the Leeward
Islands through early Sunday, and then move north of the northern
Leeward Islands by Sunday afternoon. Fluctuations in intensity
are possible during the next few days, but Tammy is expected to
remain a hurricane while it passes near or over the Leeward
Islands. 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.

East Atlantic Storm Warning: Meteo-France has issued a STORM
WARNING for the Irving and Madeira Offshore Zones. Please see the
latest High Seas Warning and High Seas Forecast issued by Meteo-
France at https://wwmiws.wmo.int/index.php/affiche/2 for more
information.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough exits the coast of Africa near 13N17W and
continues to 12N20W. The ITCZ begins at 12N20W and continues to
08N33W. Scattered moderate convection is from 05N to 10N between
20W and 30W.

GULF OF MEXICO...

A cold front extends from just north of Tampa Bay, Florida, to
28N86W. A stationary front continues from 28N86W to Galveston,
Texas. Surface observations show gentle to moderate NE winds north
of the front with 2-4 ft seas. 1016 mb high pressure is centered
near 24N91W. Light to gentle anticyclonic flow prevails over the
remainder of the Gulf of Mexico, with 2-4 ft seas.

For the forecast, the cold front will move southward today while
weakening. Another cold front will move through the NE Gulf Sun
through Mon. Looking ahead, high pressure building in the wake of
the front will support moderate to fresh E winds and building seas
Sun night through the middle of next week.

CARIBBEAN SEA...

Please see SPECIAL FEATURES section above for information on
HURRICANE TAMMY.

Seas of 8-12 ft are noted in some Atlantic passages between the
Northern Leeward Islands, in the vicinity of Hurricane Tammy.
Light to gentle trades prevail in the Eastern and Central
Caribbean with 3-5 ft seas. In the Western Caribbean, gentle N
winds have been observed by scatterometer, with seas of 1-3 ft.
Scattered moderate convection is noted in the southwest Caribbean,
from 09N to 15N between 75W and 84W.

For the forecast, Hurricane Tammy will move to 17.0N 61.6W this
evening, 18.6N 62.5W Sun morning, 20.0N 63.3W Sun evening, 21.3N
63.8W Mon morning, 22.3N 63.8W Mon evening, and 23.2N 63.5W Tue
morning. Tammy will change little in intensity as it moves to near
24.9N 62.7W and farther N of the Leeward Islands early Wed. An
area of low pressure is over the far southwestern Caribbean. Some
slow development of this system is possible during the next few
days while it moves slowly westward over the southwestern
Caribbean Sea. The disturbance is forecast to move inland over
Central America Monday or early Tuesday, and no further
development is expected after that time. A weak cold front will
move into the northwest Caribbean by late Mon.

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section for information on
HURRICANE TAMMY and an EAST ATLANTIC STORM WARNING issued by
Meteo-France.

A cold front extends from 31N73W to Cape Canaveral, Florida. Fresh
to locally strong WNW winds are north of the front. A surface
trough is from 31N66W to 21N72W. Scattered showers are along the
surface trough. In the vicinity of these two features, 8-12 ft
seas are north of a line from 31N59W to 28N75W to 31N78W. In the
central tropical Atlantic, as surface trough extends from 14N42W
to 05N49W. Scattered moderate isolated strong convection is from
06N to 14N between 40W and 50W. Scatterometer data showed fresh
to strong E winds near this surface trough with seas of 6-8 ft. In
the northeastern tropical Atlantic, a cold front extends from
31N20W to 28N28W to 30N37W. Fresh to strong NW winds are north of
the cold front with 8-12 ft seas. Elsewhere in the Atlantic, E
winds are moderate with 4-7 ft seas in open waters.

For the forecast W of 55W, Hurricane Tammy will move to 17.0N
61.6W this evening, 18.6N 62.5W Sun morning, 20.0N 63.3W Sun
evening, 21.3N 63.8W Mon morning, 22.3N 63.8W Mon evening, and
23.2N 63.5W Tue morning. Tammy will change little in intensity as
it moves to near early Wed. Farther W, a cold front extends from
31N73W to northern Florida. This front will weaken and stall E of
Bermuda early next week. A second cold front will follow, moving
off the northeast Florida coast late Sun, reach from Bermuda to
Fort Lauderdale, Florida, by early Mon.

$$
Mahoney
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