[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200407
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Dec 20 2022

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
0355 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A 1014 mb low pressure system is
located near 28N94W and a cold front extends from the low to
23N98W. A warm front extends from the low center to SE Louisiana.
Scattered showers and isolated thunderstorms are affecting the
waters N of 23N and between 86W and 94W. Fresh to strong cyclonic
winds are observed N of 25N and W of 90W. Seas in these waters are
5-8 ft. The low will move eastward across the Gulf of Mexico
through Tue, with a cold front extending SSW and a warm front
extending E from the low. The gradient between the low and strong
high pressure over the SE United States will cause winds to gale
force over the NE Gulf of Mexico on Tue afternoon. Seas will build
to near 10 ft in the northern Gulf. The low will shift east-southeast
toward South Florida by late Tue night while the cold front
slowly moves eastward, stalling and weakening by mid-week. Fresh
to strong N winds are expected behind the front Tue and Tue
evening. Scattered showers and thunderstorms are expected with the
low and front. Winds and seas will diminish in the NE Gulf late
Wed into Thu.

Please read the latest High Seas Forecast issued by the National
Hurricane Center at http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml
for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Guinea-Bissau near 11N16W and continues to 06N20W. The ITCZ
stretches from 06N20W to 03N35W to 02N50W. Scattered moderate
convection is noted S of 07N and between 15W and 40W.

GULF OF MEXICO...

Please read the Special Features section above for information
on the developing gales in association with the low pressure
system over the NW Gulf of Mexico.

Outside of the impacts of the low pressure mentioned above in the
Special Features section, high pressure over the eastern United
States dominates the rest of the Gulf of Mexico. Moderate to
locally fresh easterly winds are present E of 90W. Seas in these
waters are 3-6 ft, with the highest seas occurring in the Florida
Straits. Moderate or weaker winds and seas of 3-6 ft are found S
of 25N and W of 90W.

For the forecast, looking ahead, a stronger cold front is
expected to move off the Texas coast Thu evening followed by near-
gale to gale force winds and rough to very rough seas across the
basin through Fri night, with strong gales possible off Veracruz.


CARIBBEAN SEA...

A strong ridge over the eastern United States extends southward
into the Caribbean Sea, maintaining fairly tranquil weather
conditions. The exception are isolated pockets of shallow
moisture traversing the basin in the trade flow. The pressure
gradient between the strong high pressure and lower pressure in
northern South America result in fresh to strong easterly trade
breezes in the central Caribbean, with the strongest winds
occurring offshore Colombia. Seas in these waters are 5-8 ft.
Moderate to locally fresh easterly winds are evident in satellite
derived wind data in the eastern Caribbean. Seas in the area
described are 3-6 ft. Moderate or weaker winds and slight to
moderate seas are observed elsewhere.

For the forecast, surface ridging north of the region will maintain
fresh to strong NE to E tradewinds across the central and SW
Caribbean Sea through Fri night. Moderate to locally fresh winds
will prevail in the E Caribbean with gentle to moderate winds in
the W Caribbean. Long-period N to NE swell will continue to move
into the tropical Atlantic waters for the next several days. A
cold front will move into the Yucatan Channel by late Fri and
reach from central Cuba to Belize by Sat night. Fresh to locally
strong winds and rough seas will follow the front.

ATLANTIC OCEAN...

A weak cold front extends from 31N55W to 27N65W, where it becomes
a dissipating stationary front that extends southwestward to the
Florida Straits. A few showers are noted near the frontal
boundary, but no deep convection is evident. Moderate to fresh
N-NW winds are present behind the frontal boundary, with the
strongest winds occurring near 27N70W. Seas behind the cold front
are 5-10 ft, with the highest seas occurring N of 26N and E of
72W. Moderate to fresh SW winds are found ahead of the front,
mainly N of 28N and between 43W and 56W.

The remainder of the tropical Atlantic waters are dominated by a
1023 mb high pressure system positioned near 27N39W. The pressure
gradient between this ridge and lower pressures in the deep
tropics result in moderate to fresh easterly trade winds S of 22N
and between Africa and the Lesser Antilles. Seas in these waters
are 6-9 ft with the highest seas occurring just west of the Cabo
Verde Islands. Moderate or weaker winds and moderate seas prevail
elsewhere in the basin.

For the forecast west of 55W, the aforementioned cold front will
extend from 31N49W to 23N67W to 24.5N71W Tue evening. A low pres
along this stationary front over the Gulf of Mexico will cross
South Florida Tue night and move northeast near the NW Bahamas Wed
morning. The low pres is expected to develop gale force winds on
Wed as it continues east along 26/27N to the east of the Bahamas.
These gales should diminish by early Thu as the low nears 26N65W.
At the same time, a second area of gales is expected to form Wed
morning to the east of N Florida, associated with a sharp surface
trough. Winds will become more southerly Thu ahead of a stronger
cold front expected to move off the northeast Florida coast Fri,
accompanied by strong to near-gale force winds and rough seas.
Gales are possible to the east of northern Florida with this next
front.

$$
DELGADO
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