Tropical Weather Discussion
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000
AXNT20 KNHC 050603
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
103 AM EST Tue Dec 5 2017

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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...
A middle level to upper level trough passes through 32N54W to
28N62W and 22N67W. The trough supports a 1001 mb low pressure
center that is to the N of the discussion area near 35N56W.
Rainshowers are possible to the north of the line that passes
through 32N45W to 25N70W and 24N75W. The 1001 mb low pressure
center is forecast to deepen during the next 24 hours, while
moving E-SE. A cold front currently passes through 32N53W to
30N56W to 28N62W. The forecast for the next 24 hours: W-to-NW
gale-force winds, and sea heights from 10 feet to 12 feet, N of
30N W of the cold front to 58W. Please read the latest NWS High
Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 for more
details.

...ITCZ/MONSOON TROUGH...
The monsoon trough passes through the coastal sections of Sierra
Leone near 09N13W to 07N19W. The ITCZ continues from 07N19W to
05N30W 04N40W, to 05N52W at the coast of French Guiana.
Precipitation: isolated moderate to locally strong rainshowers
are within 120 nm on either side of 04N03W 05N30W 04N46W 05N56W.

...DISCUSSION...

THE GULF OF MEXICO...

Broad middle level to upper level NW wind flow spans the entire
Gulf of Mexico. Comparatively-drier air in subsidence is to the
north of the line from 24N98W at the coast of Mexico, to Yucatan
Channel.

A surface ridge passes through NW Florida, to 27N85W, 24N90W, and
to 20N96W in the SW corner of the area.

...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL PLATFORM
SITES, THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

LIFR: none. IFR: none. MVFR: KBQX, KVAF, and KEMK.

CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS: MVFR-to-IFR and light rain, from Port Lavaca to the Houston
metropolitan area, and to Huntsville. MISSISSIPPI: LIFR and fog
in the coastal plains. ALABAMA: MVFR in the Mobile metropolitan
area. S sections. FLORIDA: MVFR-to-IFR in the Panhandle.

THE CARIBBEAN SEA...

Large scale upper level anticyclonic wind flow moves through the
SW corner of the area, toward Hispaniola, and then curving toward
the east and southeast.

Middle level-to-700 mb NE wind flow covers the area that is from
14N northward between 68W and 80W. Middle level-to-700 mb E wind
flow covers the area that is from 15N northward from 80W westward.

Middle level-to-700 mb level cyclonic wind flow is under upper
level SW wind flow, in the SW corner of the Caribbean Sea. The
monsoon trough is in the eastern Pacific Ocean along 06N/07N
between 79W and beyond 86W. Precipitation:
isolated moderate to locally strong from 12N southward between 77W
to the SE coast of Nicaragua.

A surface trough is in the SE corner of the Caribbean Sea, along
16N60W 13N61W, toward NE Venezuela and Trinidad. Precipitation:
rainshowers are possible from 17N southward between 60W and 70W.

24-hour rainfall totals in inches, for the period that ended at
05/0000 UTC, according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.06 in
Curacao.

...HISPANIOLA...

Upper level NW wind flow is moving across the area. Large scale
upper level anticyclonic wind flow moves through the SW corner of
the area, toward Hispaniola, and then curving toward the east and
southeast.

SURFACE OBSERVATIONS...VFR for Port-au-Prince in Haiti. in the
DOMINICAN REPUBLIC: VFR in Santo Domingo, after earlier
observations of MVFR and a ceiling at 1800 feet. Barahona: VFR,
few cumulonimbus clouds. Puerto Plata: MVFR. ceiling 1800 feet.
VFR at the other observation sites in the Dominican Republic.

The GFS MODEL forecast for 250 mb shows that a ridge will start
along the line from Colombia to the offshore waters of eastern and
central Honduras. Expect SW wind flow during day one. The SW wind
flow will become westerly during day two. The GFS MODEL forecast
for 500 mb shows that anticyclonic wind flow at the start of the
48-hour forecast period will switch to NW, with a developing
east-to-west oriented trough. A col point will end up in the
central sections of the Dominican Republic. A NE-to-SW oriented
trough will develop to the east of the col point, and SE-to-NW
oriented trough will develop to the west of the col point.
The GFS MODEL forecast for 700 mb shows that day one will start
with SE wind flow across the area, changing to cyclonic wind flow
in Haiti, and anticyclonic wind flow in the Dominican Republic,
and eventually NE wind flow at the end of day one. An anticyclonic
circulation center will be just off the SE coast of Cuba at the
end of day one. An inverted trough will persist across Hispaniola
during day two.

THE ATLANTIC OCEAN...

An upper level trough passes through 32N32W to 25N33W. The trough
supports a cold front that passes through 32N30W 26N42W. A
stationary front continues from 26N42W to 23N55W and 21N68W.
Precipitation: isolated moderate rainshowers within 180 nm on
either side of the line that passes through 32N28W, 28N44W,
23N56W, 21N65W, to SE Cuba near 20N75W. Part of this precipitation
is in the waters that are to the north of Hispaniola, Puerto
Rico, and the NE Caribbean Sea islands.

A surface trough is along the coast of Africa and into the Western
Sahara, passing through 32N10W to 28N14W to 22N16W. No significant
deep convective precipitation is apparent in satellite imagery.

A surface ridge passes through 32N20W to 28N26W to 22N36W, to
20N52W and 20N63W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT



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