Tropical Weather Discussion
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000
AXNT20 KNHC 131805
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 PM EST Wed Dec 13 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

...GALE-FORCE WINDS IN THE ATLANTIC OCEAN...

A cold front passes through 31N68W, to 24N81W in the Straits of
Florida. Expect SW gale-force winds, and sea heights ranging from
12 feet to 14 feet, to the north of 30N to the E of the cold
front to 67W. The gale-force winds are forecast to be slowing down
during the next few hours, to less than gale-force. Please read
the latest NWS High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 for more details.

An upper level trough passes through 32N75W, across the Bahamas,
to 23N78W between the Bahamas and Cuba. Comparatively drier air
is to the NW of the line that passes through 32N61W to 25N70W, to
22N80W in Cuba.

...ITCZ/MONSOON TROUGH...
The monsoon trough passes through the coastal sections of Liberia
near 06N11W, to 06N18W. The ITCZ continues from 06N18W to 05N27W
04N40W and 04N48W. Precipitation: widely scattered to scattered moderate
and isolated strong rainshowers from 04N to 09N between 25W and 50W.

...DISCUSSION...

THE GULF OF MEXICO...

Middle level to upper level NW to W wind flow is moving across the
open waters of the Gulf of Mexico.

A cold front passes through the Atlantic Ocean, through the
Straits of Florida near 24N81W, to 23N96W, in the western sections
of the Gulf of Mexico. Fair skies and fair weather abound.

...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...

VFR, at all the observation/platform sites.

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

CONDITIONS WITH THE CURRENT GULF OF MEXICO FRONT BOUNDARY:
VFR, everywhere.

THE CARIBBEAN SEA...

A dissipating stationary front passes through the Atlantic Ocean,
to the NW corner of Haiti, into the Windward Passage, just to the
east of Jamaica, to 16N78W, and to 12N79W. Precipitation: isolated
moderate rainshowers within 180 nm on either side of the line from
20N74W in the Windward Passage, to 14N79W, to the Panama/Costa
Rica border. A surface trough is along 18N72W 15N73W 13N73W.
Rainshowers are possible from 14N to 16N between 71W and 73W.

An upper level ridge extends from NW Colombia, through Costa Rica,
into the eastern Pacific Ocean near 10N98W.

Middle level to upper level cyclonic wind flow, with an inverted
trough, covers the area that is from 15N southward between 64W and
70W. A surface trough is along 17N68W 14N69W, to the coast of
Venezuela along 69W. Precipitation: rainshowers are possible from
15N southward between 64W and 70W, and from 09N to 12N between 59W
and 62W, in the coastal waters of Trinidad and Venezuela.

The monsoon trough is along 09N/10N between 74W in Colombia and
85W/86W in western sections of Costa Rica.

24-hour rainfall totals in inches, for the period that ended at
13/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.54 in
Montego Bay in Jamaica, 0.15 in Trinidad, and 0.01 in Guadeloupe.

...HISPANIOLA...

Upper level anticyclonic wind flow is moving across the island.

SURFACE OBSERVATIONS...HAITI, in Port-au-Prince: VFR. in the
DOMINICAN REPUBLIC: VFR at all the observation stations.

The GFS MODEL forecast for 250 mb shows that SW, W, and finally NW
wind flow will move across the area. An anticyclonic circulation
center will start near the Colombia/Panama coast, and it will move
into the S central Caribbean Sea waters. The GFS MODEL forecast
for 500 mb shows that anticyclonic wind flow will move across the
area. Day one will consist of an east-to-west oriented ridge. Day
two will consist of a west-to-east oriented ridge. The GFS MODEL
forecast for 700 mb shows that broad anticyclonic wind flow will
move across the area. NE-to-E wind flow will be moving across the
area at the end of the 48-hour forecast period, with an Atlantic
Ocean-to-SE Cuba ridge.

THE ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section for information about the
current cold front, and the gale-force winds.

One upper level cyclonic circulation center is near 25N37W. A
second upper level cyclonic circulation center is near 19N44W.
Low clouds and possible rainshowers cover the area that is from
15N to 23N between 40W and 48W, in an area of clouds that is
moving toward the southwest.

A dissipating stationary front passes through 32N59W to 25N66W, to
NW Haiti, continuing into the Caribbean Sea. Upper level SW wind
flow is moving on top of the area of the dissipating frontal
boundary. Precipitation: widely scattered moderate to isolated
strong rainshowers are from 29N northward between 56W and 59W.
rainshowers are possible elsewhere within 120 nm on either side of
30N59W 25N64W, into the Windward Passage.

A surface trough is along 27N52W 22N53W 20N55W and 17N60W.
Rainshowers are possible within 75 nm on either side of 31N52W
24N52W 20N53W, and within 120 nm on either side of 20N53W 19N60W.

Surface anticyclonic wind flow covers the Atlantic Ocean from 20N
northward between Africa and 50W. 44W and 74W. A 1024 mb high
pressure center is near 29N58W.

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

$$
MT


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