[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140000
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 PM EST TUE DEC 13 2016

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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...THE ITCZ/THE MONSOON TROUGH...

The Monsoon Trough reaches the coastal sections of Liberia near
06N10W to 06N13W. The ITCZ continues from 06N13W to 06N21W and
04N32W and 05N35W. Convective precipitation: scattered moderate
to strong from 06N to 08N between 17W and 20W. widely scattered
moderate to isolated strong elsewhere from 10N southward from
40W eastward, in disorganized precipitation. rainshowers also
area from 09N southward between 50W and 60W

A surface trough is along 08N42W 06N43W 03N44W. Convective
precipitation: isolated moderate from 10N southward between
40W and 50W.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level westerly wind flow moves from Texas, and from 23N
along the coast of Mexico northward, into the western half of
the Gulf of Mexico, from 23N northward. Upper level SW wind flow
moves through Mexico, into the Gulf of Mexico. It is within 120
nm on either side of the line that passes through 21N97W at the
coast, to 24N90W, beyond 28N80W. Comparatively drier air in
subsidence is apparent in water vapor imagery from 29N southward.

A surface ridge passes through a NE Gulf of Mexico 1019 mb high
pressure center, into the central Gulf of Mexico, to 23N94W, to
an inland Mexico 1020 mb high pressure center that is near
22N101W.

...LOW LEVEL CLOUD CEILINGS 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: KMIS.

MVFR: KBBF, KBQX, KXIH, KVAF, KGUL, KIKT, and KVOA.

LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS: MVFR in Edinburg. a mixture of LIFR/IFR/MVFR in the
middle Texas coastal plains. MVFR from Victoria to Sugar Land.
MVFR from Ellington Field to Conroe. MVFR in Beaumont/Port
Arthur and Jasper. LOUISIANA: MVFR from parts of the Lake
Charles metropolitan area to Patterson and Galliano. thunder and
rain in Baton Rouge, and on the north side of Lake
Pontchartrain. light rain at the NAS New Orleans. MISSISSIPPI: a
mixture of LIFR/IFR/MVFR along the Gulf of Mexico coast. rain
and thunder and LIFR/MVFR from Natchez to Hattiesburg. ALABAMA:
MVFR from the immediate coastal plains to Evergreen. thunder and
rain in Fort Rucker. FLORIDA: light rain in Milton and Marianna.
MVFR from Pensacola westward.

...THE CARIBBEAN SEA...

An upper level ridge extends from the coastal sections of north
central Venezuela, northwestward, to the Yucatan Peninsula.
Comparatively drier air in subsidence is apparent in water vapor
imagery from 75W eastward.

The monsoon trough is along 10N from 74W in northern Colombia
beyond NW Costa Rica. Convective precipitation: isolated
moderate from 13N southward from 76W westward.

24-HOUR rainfall totals in inches for the period ending at
13/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.54 in
Trinidad, 0.43 in St. Thomas in the U.S.A. Virgin Islands, 0.34
in Freeport in the Bahamas, 0.09 in San Juan in Puerto Rico,
0.07 in Curacao, 0.05 in Guadeloupe, and 0.01 in Merida in
Mexico.

...HISPANIOLA...

Upper level SW wind flow is moving across Hispaniola. Convective
precipitation: Rainshowers are possible across Hispaniola, and
in the coastal waters and coastal plains, in areas of broken low
level to middle level clouds. Isolated moderate from 20N to 24N
between 70W and 74W, in the waters that are around the Bahamas,
and to the north of Hispaniola.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR/no
ceiling. for the DOMINICAN REPUBLIC: Barahona: VFR/no ceiling.
few cumulonimbus clouds. Santo Domingo: nearby rainshowers.
MVFR. ceiling at 1700 feet. La Romana: nearby rainshowers have
ended for the moment. VFR/no ceiling. few cumulonimbus clouds.
Punta Cana: VFR/no ceiling. Santiago and Puerto Plata: VFR/no
ceiling.

The GFS MODEL forecast for 250 MB shows that an anticyclonic
circulation center will be about 180 nm to the south of Puerto
Rico. The anticyclonic center is forecast to move SE with time,
and then open into a ridge, during the first 18 hours to 24
hours of the 48=hour forecast period. Expect SW wind flow across
Hispaniola with the anticyclonic circulation center/ridge. Broad
W wind flow spans Hispaniola for the rest of the forecast period.
The GFS MODEL forecast for 500 MB shows that an anticyclonic
circulation center is along the northern coast of Hispaniola for
the first 12 hours. The anticyclonic circulation center moves
into the Windward Passage for another 24 hours or so. An E-to-W
oriented ridge eventually develops across Hispaniola after the
anticyclonic center dissipates. Expect anticyclonic wind flow
across Hispaniola for the next 48 hours. The GFS MODEL forecast
for 700 mb shows that anticyclonic wind flow will move across
the area for the first 18 hours or so, with an E-to-W oriented
Atlantic Ocean ridge. An inverted trough will bring NE wind
flow, and then cyclonic wind flow, for the rest of the 48-hour
forecast period.

...THE ATLANTIC OCEAN...

Upper level W-to-NW wind flow covers the Atlantic Ocean from 60W
westward.

A cold front is along 32N between 67W and 74W. The front becomes
stationary from 32N74W, beyond southern South Carolina.
Convective precipitation: isolated moderate from 27N to 32N
between 57W and 74W.

An upper level trough passes through the Madeira Archipelago to
the Canary Islands. A cold front passes through 32N22W to 28N30W
to 27N36W. The front is dissipating stationary from 27N36W to
26N47W and 25N50W. Convective precipitation: rainshowers are
possible to the north of 23N50W 24N40W 25N30W, beyond 32N16W.

A surface ridge extends from a 1028 mb high pressure center that
is near 34N36W, through 32N43W, 29N59W. 29N71W, into the NE
corner of the Gulf of Mexico.

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

$$
MT
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