[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202329
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Wed Dec 21 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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A 1015 mb low pressure is centered
near 28.5N88.5W with a cold front extending south-southwestward
from the low to 18N95W and a stationary front extending eastward
from the low to Cedar Key, Florida. The low will move east-
southeast across the eastern Gulf of Mexico through this evening.
Gale force E winds are likely currently occurring near the
stationary front from 28N to 29.5N between 84W-88.5W. Buoy 42040
near 29.2N 88.2W recorded a sustained 1-min wind of 35 kt gusting
to 41 kt at 20/2138 UTC at an elevation of 4 meters. Seas of 6 to
9 ft are generally expected over the NE and north-central Gulf
through this evening. Winds in the NE Gulf should diminish below
gale force by this evening. Meanwhile, gale force NW winds are
likely occurring within 60 nm of the coast of Vercruz, Mexico
behind the cold front. Winds are forecast to diminish below gale
force there tonight around 21/0600 UTC. Seas are forecast to peak
around 10 ft this evening with those gale force winds. The low
will shift toward S Florida by late tonight while the cold front
slowly moves eastward, stalling and weakening by mid-week. Fresh
to strong N winds are expected elsewhere behind the front through
this evening.

West Atlantic Gale Warning: A low pressure over the Gulf of
Mexico will cross South Florida tonight and move east-northeast
near the NW Bahamas by Wed morning. The low will support NE to E
gale force winds Wed through Wed evening just northeast of the
Bahamas, as the low moves eastward along 26/27N. These gales
should diminish by early Thursday as the low reaches near 26N65W.
At the same time, a second area of gales is expected to form
Wednesday morning to the east of N Florida, associated with a
separate low pressure along a sharp surface trough. Winds will
gradually weaken in our waters south of 31N Wed night as the
trough lifts northeastward. Peak seas should reach around 10-11 ft
northeast of the Bahamas and 12-13 ft east of N Florida Wed.

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 on both Gale Warnings.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Liberia near 06.5N11W
to 06N13W. The ITCZ continues from 06N13W to 02N32W to 03.5N42W.
Scattered moderate convection is noted from 02N-10N between
05W-21W, and from the Equator to 05N between 21W-43W.

GULF OF MEXICO...

Please read the Special Features section above for information
on the two gale areas over the Gulf of Mexico. Numerous moderate
isolated strong convection is noted east of 87W from 23.5N-28N.
Scattered moderate isolated strong convection is seen from
28N-29.5N between 87W-89W. Scattered moderate convection is noted
from 19N-22N between 91.5W-94.5W.

Outside of the impacts of the low pressure and frontal boundaries
mentioned above in the Special Features section, gentle to
moderate winds are occurring south of 24.5N and east of 91.5W,
where seas are likely 3 to 4 ft. Seas in the strong winds west of
the cold front and north of the stationary front are mostly 6 to 8
ft, with a few locations up to 9 ft on the N side of the low
pressure.

For the forecast, looking ahead, a stronger cold front is
expected to move off the Texas coast by early Thu evening. The
front will reach from near 29N83W to 21N97W early Fri, from the
Straits of Florida to Cancun, Mexico to the eastern Bay of
Campeche Fri evening, and move SE of the basin later on Fri night.
Near-gale to gale force NW to N winds and rough to very rough
seas will follow the front across the basin through Fri night,
with strong gales possible off Veracruz beginning Fri. Strong to
near-gale force winds could last through Sat across portions of
the south-central and southwestern Gulf. Seas of 12 to 18 ft are
expected during this event.

CARIBBEAN SEA...

Fresh trades prevail across the central Caribbean with moderate
trades elsewhere, except for gentle to moderate in the NW
Caribbean. Seas are 8-10 ft between Jamaica and Panama, according
to an altimeter pass from 20/1500 UTC. Seas are likely generally
6-8 ft elsewhere between 68W-82W from 09.5N to 17.5N. Outside of
that area, seas are 4-6 ft, except 3-5 ft in the NW Caribbean. No
significant convection is noted, aside from isolated showers in
the NW Caribbean.

For the forecast, surface ridging north of the region will
support pulsing fresh to strong NE to E tradewinds across the
central and SW Caribbean through the week and weekend. Moderate to
fresh winds will prevail in the E Caribbean with gentle to
moderate winds in the W Caribbean. A cold front will move into
the Yucatan Channel Fri evening and reach from central Cuba to
Belize by Sat night. Fresh to locally strong winds and rough seas
will follow the front.

ATLANTIC OCEAN...

Please read the Special Features section for details on two gale
warnings in the western Atlantic.

A cold front extends from 31N51W to 24N64W to 24N67W, then
continues as a shearline to across the Central Bahamas and the
Straits of Florida. A surface trough extends from 27N56W to
21N62W. Scattered moderate convection is noted north of 28.5N
between 44W-50W. Isolated moderate convection is from 24N-26N
between 55.5W-58W. Surface ridging north of the cold front/shear
line extends from 31N74W to 28N65W to 27.5N60W. Gentle to moderate
winds are near the ridge axis. Fresh E winds are north of the
shear line extending E from the NW Bahamas. Fresh ESE winds have
also developed to the E of northern Florida. Fresh NW winds are NW
of the cold front, generally north of 29N between 53W-64W. Fresh
SW winds are ahead of the cold front to 43W, north of 28N. Another
surface ridge extends from near 31N22W to 23N60W. Light to gentle
winds are near this ridge axis. The pressure gradient between
this eastern surface ridge and the ITCZ is forcing moderate to
fresh NE to E trades in the tropical latitudes. Seas are generally
7 to 9 ft across much of the Atlantic east of 60W due to wind
waves and NW to N swell, except up to 10 ft north of 30N. West of
60W and south of 29N, seas are generally 6-8 ft to the north and
east of the Bahamas. Seas are 8-9 ft north of 29N between 60W-70W.

For the forecast west of 55W, the cold front will continue moving
slowly E tonight. A low pres currently over the Gulf of Mexico
will cross South Florida tonight and move ENE near the NW Bahamas
by Wed morning. Another low will develop N of the area along 80W.
These lows will support NE gale-force winds across the west
Atlantic on Wed, described above. These gales should diminish by
early Thu. Winds will become southerly Thu ahead of a stronger
cold front expected to move off the northeast Florida coast Fri,
accompanied by strong to near-gale force W winds and rough seas.
W gales are possible to the east of northern Florida with this
front on Fri.

$$
Hagen
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