[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181748
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1248 PM EST Wed Dec 18 2019

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1720 UTC.

...SPECIAL FEATURES...

A cold front continues to press eastward across the eastern Gulf
of Mexico. This is enhancing gale force winds in the SW Gulf,
mostly S of 21N and W of 91W. Seas will range between 14-20 ft in
N to NE swell. Expect gale force winds to continue through this
evening. Gale force winds are also noted behind the cold front
near the Yucatan Channel, S of 24N and W of 84W. These gale force
winds are expected to continue moving into the Yucatan Channel and
end by this evening. Elsewhere behind the front, strong winds
will continue through tonight with frequent gusts to gale force, S
of 30N and W of 81W. Seas will range between 9-16 ft in this
area. See the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for further details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Sierra Leone near
07N12W to 05N18W. The ITCZ continues from that point west to
01N30W to NE Brazil near 01S46W. Scattered moderate convection is
seen within 150 nm on either side of the ITCZ between 19W-38W.
Scattered showers and thunderstorms are seen near the coast of
Sierra Leone.

GULF OF MEXICO...

See the section above for details on the Gale Warning in the
Gulf of Mexico.

As of 18/1500 UTC, the cold front extends off the southwest
Florida coast near 26N82W southwestward to the northern Yucatan
near 21N87W. Scattered thunderstorms are within 70 nm of the front
and currently entering the Yucatan Passage. High pressure is
filling in behind the front and is covering most of the Gulf. The
latest scatterometer data depicts northerly gale force winds
behind the front near the Yucatan Passage, S of 23N between 85W-
87W. Strong winds cover the eastern half of the Gulf in addition
to the SW Gulf with moderate northerly winds off the SE Texas
coast.

The strong cold front will move southeast of the area later
today. Northerly gale-force winds and large seas behind the front
in the SW Gulf will persist through the early evening. The wind
speeds and the sea heights will diminish in the central and
western sections of the Gulf on Thursday and Thursday night.
Strong NE to E winds will continue in the Straits of Florida
after the frontal passage from Thursday through Friday night. A
low pressure center is expected to develop in the eastern Gulf on
Friday night and move across northern Florida during the weekend.
Gale-force winds are possible in the eastern Gulf with the low
pressure center.

Strong frontal northerlies across the Gulf of Mexico on Tuesday-
Wednesday will result in heavy rainfall amounts between the
Mexican States of Veracruz and Tabasco/Campeche. In this area,
expect maxima of 4-6 inches on Tuesday. On Wednesday and Thursday,
expect additional rainfall amounts of 1-3 inches.

CARIBBEAN SEA...

As of 18/1500 UTC, a pre-frontal trough is in the NW Caribbean
ahead of the incoming strong cold front, analyzed from 16N88W to
23N82W. Scattered moderate convection is seen along this trough
and ahead of the cold front from 16N-23N between 82W-88W.
Scattered thunderstorms are also seen off the SE Cuban coast
between 76W- 79W. The 1007 mb Colombian low has meandered into the
SW Caribbean near 10N77W. Scattered showers with isolated
thunderstorms are noted throughout this area, S of 13N between
76W-84W. Upper level ridging extends across the eastern Caribbean,
inhibiting deep convection. Low- topped showers can be seen
moving across the the area. The latest scatterometer data depicts
strong trades north of Colombia with fresh to strong winds in the
eastern and central Caribbean. Light winds are east of the pre-
frontal trough, with moderate to fresh winds behind the trough.

High pressure north of the region will maintain fresh to strong
trade winds and building seas from the tropical north Atlantic
Ocean westward to the south central Caribbean Sea through
Saturday. A strong cold front will move into the Yucatan Channel
this afternoon. The front will stall and weaken from central Cuba
to Honduras by Thursday night. Fresh to strong northerly winds
will accompany the front in the NW Caribbean Sea.

The strong frontal northerlies will bring heavy rainfall across
northwest Honduras to Puerto Barrios in central Guatemala. The
heaviest rainfall will occur on Wednesday to Thursday with maxima
of 6-8 inches. Due to strong topographical forcing, localized
maxima is expected to be between 10-12 inches.

ATLANTIC OCEAN...

As of 18/1500 UTC, a cold front continues pressing south and east
in the western Atlantic, from 31N76W to central Florida near
27N80W. A pre-frontal trough is analyzed from 25N79W to 30N75W.
Scattered showers with isolated thunderstorms are seen within 100
nm of the front. Another cold front enters the central Atlantic
near 31N27W and stretches westward to 26N42W. A pre-frontal
trough is also analyzed ahead of this front from 25N35W to
30N22W. Showers are seen within 90 nm of these features. High
pressure dominates the rest of the basin anchored by a 1025 mb
high near 27N44W. The latest scatterometer data depicts strong
northerly winds behind the cold front in the western Atlantic,
with moderate to fresh southerly winds ahead of the front.

The strong cold front will reach from 31N69W to eastern Cuba
tonight and from 31N64W to eastern Cuba on Thursday morning. By
Thursday night, the front will stretch from 26N65W across the
Bahamas to the Windward Passage. Strong northerly winds and
building seas are expected across much of the forecast waters
following the frontal passage. The front will stall gradually, and
weaken through Friday night. It is possible that fresh to strong
easterly winds may develop to the east of Florida during the
upcoming weekend. A low pressure center is forecast to develop in
the eastern Gulf of Mexico and move across northern Florida.

$$
AKR
This weather bulletin was brought to you by:
www.nashvilleweather.net