[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192314
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 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 1800 UTC surface analysis and satellite imagery through
2210 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through the coast of
Liberia near 06.5N11W, then continues to near 04N18W. The ITCZ
extends from 04N18W to 03.5N38W to the coast of NE Brazil near
01N50W. Scattered moderate isolated strong convection is from 0.5N
to 06.5N between 02W and 43W.

GULF OF MEXICO...

A 1014 mb low pressure system has moved to along the southern
Texas coast near 28N96W this afternoon. A warm front extends from
the low center eastward across the northern Gulf to near 28N95W.
A cold front stretches from the low center southward and then
curves inland to just S of Tampico, Mexico. Widespread patches of
light rain, showers and drizzle are affecting south Texas and NE
Mexico in association with this low. Large clusters of strong
thunderstorms are occurring north of the warm front and extend
inland across southwest and south central Louisiana, and also
across the west central Gulf, from 23.5N to 26N between 90W and
93W, along a surface trough extending SE from the surface low to
20N93.5W. Other scattered showers and isolated thunderstorms are
also noted E of the trough, N of 24N and E of 88W. The trough
combined with a ridge across the eastern Gulf supports an area of
fresh to strong E to SE winds northeast of the trough to about
90W and to the coast of SW Louisiana, where seas are 6 to 10 ft.
Moderate to fresh E winds prevail east of 90W, where seas are 4 to
7 ft, except 3 ft along the Florida Panhandle. Moderate or weaker
winds and seas of 4-6 ft are occurring southwest of the trough
including in the Bay of Campeche.

For the forecast, the aforementioned low pres 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 induce winds to gale force over the NE Gulf of
Mexico on Tue afternoon. 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.
Looking ahead, a stronger cold front is expected to move off the
Texas coast Thu evening followed by near-gale to gale force winds
across the basin through Fri night, with strong gales possible
off Veracruz.

CARIBBEAN SEA...

An old frontal trough has dissipated across the NE Caribbean
along 17N. A band of broken low clouds with possible showers is
across and to the north of 17N. Elsewhere, shallow moisture
embedded in the trade wind flow is across the basin, and will
prevail across the region through Tue producing isolated to widely
scattered passing showers. Fresh to strong NE to E winds are
evident in the south- central Caribbean, including the Gulf of
Venezuela, with strong winds near the coast of Colombia based on
recent scatterometer data. Seas in these waters are 6-9 ft.
Moderate to occasionally fresh easterly trade winds are present in
the remainder of the central and eastern Caribbean with seas of
4-6 ft. Gentle to moderate easterly breezes and seas of 3-5 ft are
observed in the NW Caribbean.

For the forecast, a ridge 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. 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 cold front enters the forecast area near 31N57W then continues
SW across the central Bahamas to the coast of western Cuba near
23N82W. Widely scattered moderate convection is occurring within
240 nm SE of the front to the E of 72W. Mainly moderate N to NE
winds are observed in the wake of the front W of 62W, except
locally fresh immediately along the front W of 66W. Moderate to
fresh NW to N winds are elsewhere behind the front E of 62W. Ahead
of the front, fresh to strong SW winds are N of 29N to about 50W
with seas of 9-12 ft in NE swell. Seas of 7-10 ft in NE swell
follow the front covering the waters E of 73W. Gentle to moderate
winds are elsewhere southeast of the front under the influence of
a ridge.

Farther east, a weakening frontal trough extends from the Madeira
Islands to 20N40W. Satellite derived wind data provide
observations of moderate to fresh trades across the tropical
Atlantic S of the trough and N of the ITCZ due to the pressure
gradient between these two features. Seas of 8-10 ft in northerly
swell dominate most of the Atlantic forecast waters E of 60W.

For the forecast west of 55W, the above mentioned cold front will
reach from 31N55W to central Cuba tonight, then extend from
31N49W to 23N67W to 24.5N71W Tue evening, with a stationary front
continuing to South Florida. A low pres along this stationary
front over the Gulf of Mexico will cross South Florida Tue night
and move E near the NW Bahamas Wed morning. The low pres is
expected to produce gale force winds on Wed as it continues E
along 26/27N to the E 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.

$$

Stripling
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