[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222302
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Thu Dec 23 2021

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
2230 UTC.

...MONSOON TROUGH/ITCZ...

The ITCZ extends from the coast of Liberia near 05N09W to 08N20W
to 02N35W to the coast of Brazil near 02N51W. Scattered moderate
convection is noted west of 46W from 01N-06N.

GULF OF MEXICO...

High pressure ridging extends from north to south across the
western half of the Gulf of Mexico, where winds are light to
gentle with 2 to 4 ft seas. Moderate to fresh N winds prevail over
the eastern half of the basin. Seas are 3 to 5 ft in the NE Gulf
and 4 to 6 ft in the SE Gulf.

For the forecast, a ridge will dominate the Gulf waters during
the next several days. By Thu night and continuing into the
weekend, fresh southerly return flow will establish over the
western Gulf.

CARIBBEAN SEA...

As of 2100 UTC, a cold front stretches from eastern Cuba near
21N77W to the Honduras/Nicaragua border near 15N83W. Isolated
showers and tstorms are along the frontal boundary. A few showers
are also noted ahead of the front in the Windward Passage. Mainly
moderate NW to N winds prevail behind the front in the NW
Caribbean, except for fresh to the north of eastern Honduras.
Winds ahead of the front are generally gentle, increasing to a
moderate to fresh easterly breeze in the eastern Caribbean. Seas
are 4 to 6 ft behind the cold front in the Western Caribbean and 3
to 5 ft elsewhere.

For the forecast, the cold front will move slowly eastward, then
stall from Haiti to near 11N81W by Fri while dissipating. Fresh to
locally strong N winds are expected behind the front offshore
Nicaragua tonight through Thu night. Elsewhere, mainly moderate
trades are expected in the eastern and central Caribbean.

ATLANTIC OCEAN...

A cold front stretches from 31N69W through the central Bahamas
near San Salvador and Long Island, and to eastern Cuba near
21N77W. Scattered moderate convection with embedded thunderstorms
is noted along and within 120 nm east of the front. Strong SW
winds are likely occurring east of the front to 60W, mainly north
of 27N. Fresh W to NW winds extend westward from the front to
Florida, from 23N to 31N. Seas of 8 to 11 ft are present north of
28N between 61W-76W. Seas of 5 to 7 ft are elsewhere west of 60W,
except lower in the shallow water near the Bahamas.

A surface trough extending from 23N61W to 18N63W contains isolated
showers. Strong SE winds are east of the surface trough. A cold
front extends from 31N21W to 25N39W to 27N46W, where it
transitions to a warm front that continues to 31N53.5W. Scattered
showers are along the cold front, mainly east of 27W. Large NW to
N swell is building southward behind the cold front. Seas of 8 to
13 ft are present north of 26N between 21W-52W. Surface high
pressure of 1028 mb is north of the front near 33N43W. Fresh to
locally strong trade winds are present from the ITCZ to 18N
between 33W and 60W, where seas are 8 to 10 ft. Seas of 6 to 8 ft
prevail elsewhere east of 60W.

For the forecast, the cold front extending from 31N69W to eastern
Cuba will reach from near Bermuda to the Windward Passage by Thu
morning, and from 31N60W to Haiti by Fri morning. Fresh to strong
winds on either side of the front will gradually diminish west of
65W through Thu night. By early Sat, the strong winds associated
with this front will be confined to areas east of 52W, north of
28N. High pressure will follow the front over the western
Atlantic, to the east of Florida, Fri into Sat, brining quieter
conditions. Looking ahead, the subtropical high pressure ridge
will sink southward to along 25N late this weekend, while a
strong low pressure develops well north of the area, over the
north Atlantic. This pattern will tighten the pressure gradient,
bringing strong to potentially near-gale force westerly winds to
areas north of 29N across much of the Atlantic Sunday into Monday.
Large NW to N swell with seas of 12 to 20 ft are possible north
of 27N and east of 70W by Mon.

$$
Hagen
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