617 
AXNT20 KNHC 160620
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Thu Dec 16 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 0000 UTC surface analysis and satellite imagery through 
0500 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea-Bissau near
11N15W to 07N19W. The ITCZ continues from 07N19W to 03N30W to
04N46W. Scattered moderate convection is noted from 02N to 06N 
between the coast of Africa near 10W and 23W. 

GULF OF MEXICO...

High pressure ridging dominates the Gulf of Mexico, keeping 
mainly dry conditions in place. Moderate winds prevail across 
the basin, except for fresh SSE off the coast of southern Texas 
and fresh NE to E in the Florida Straits and SE Gulf of Mexico. 
Seas of 3 to 5 ft continue across the basin, except 5-6 ft in 
the Florida Straits and within the area of fresh winds offshore 
Texas. 

For the forecast, high pressure will prevail across the northern
forecast waters through Sat, supporting moderate to locally
fresh winds. A cold front is forecast to enter the basin
Saturday night into early Sunday. Fresh to strong winds and
building seas will prevail west of the front.

CARIBBEAN SEA...

A diffluent pattern aloft continues to influence scattered 
showers and thunderstorms over waters south of 17N and west of 
80W. The pressure gradient created from the higher pressure 
centered over the western Atlantic and lower pressure over 
Colombia is supporting fresh to strong trade winds over most of 
the basin, including the Windward Passage. The exception is 
noted in a satellite scatterometer pass showing moderate to 
fresh trades within the NW Caribbean. Seas are 7 to 10 ft over 
the eastern and central portion of the basin, including the 
windward passage, with 5 to 8 ft seas in the NW Caribbean. 

For the forecast, strong high pressure will prevail over the 
western
Atlantic through the forecast period. This will support fresh to
strong trade winds over the eastern and central Caribbean
through the weekend. Moderate to fresh trades are expected
elsewhere. 

ATLANTIC OCEAN...

A fairly strong pressure gradient is over the western Atlantic, 
between a 1037 mb high pressure near 39N66W and a 1007 mb 
Colombian low near 10N76W. The pressure gradient is allowing for 
fresh to strong E winds south of 29N to the Greater Antilles, 
between 50W and the coast of Florida, including the Bahamas 
region. A cold front enters the area near 31N45W to 28N56W and 
extends northwestward to 31N66W. Strong N winds are north of the 
front. A surface trough extends from 31N40W to 24N54W. Fresh N 
winds are N of the trough, while gentle to moderate winds are 
south of it and elsewhere east of 45W. 

West of 50W, seas are generally 6-9 ft, except up to 12 ft 
behind the cold front. East of 45W, seas are generally 5-7 ft.

For the forecast, fresh to strong winds will continue west of 
65W, especially south of 27N, through Thu as high pressure north 
of the area builds southward. Another cold front may bring 
increasing winds and seas north of 27N between 40W and Florida 
by early Mon.

$$
Mora