[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171804
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 PM EST SAT DEC 17 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

A strong cold front will cross the western Gulf of Mexico on
Sunday morning. High pressure, that will behind the front, will
support gale-force northerly winds in sections of the western
Gulf of Mexico beginning on Sunday morning. The gale-force winds
then will become confined to the southwestern Gulf of Mexico by
Sunday night. The cold front will be along 30N92W 26N97W. Expect
N gale-force winds and sea heights reaching 9 feet, to the NW of
the cold front. Please read the Atlantic high seas forecast,
that is listed under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC,
for more details.

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

The Monsoon Trough reaches the coastal sections of Liberia near
05N09W to 05N11W. The ITCZ continues from 05N11W to 03N22W and
04N40W. Convective precipitation: widely scattered moderate to
isolated strong from 12N southward from 32W eastward. isolated
moderate elsewhere from 10N southward from between 32W and 60W.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level SW wind flow spans the entire Gulf of Mexico.
Southerly surface wind flow covers the area also. The weather
pattern is setting itself up for the arrival of a cold front on
Sunday morning, that is forecast to bring gale-force winds with
it. Please read the SPECIAL FEATURES section for more details.

...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: KVAF.

MVFR: KBBF, KBQX, KXIH, KHHV, KEMK, KGUL, KHQI, KGHB, KATP,
KGRY, KIKT, KMIS, and KDLP.

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 Brownsville and Port Isabel in the Lower Valley.
MVFR in Hebbronville and Rockport. MVFR in Victoria and Palacios.
LIFR in Port Lavaca. MVFR from Bay City to Conroe, in Galveston,
Beaumont/Port Arthur, and in Jasper. LOUISIANA: MVFR in the
southern coastal plains, and around Lake Pontchartrain.
MISSISSIPPI: light rain in McComb. MVFR in the southernmost
coastal sections of the state. ALABAMA: MVFR in the Mobile
metropolitan area, and in Evergreen. FLORIDA: light rain in
Milton. MVFR in Apalachicola and Tallahassee. MVFR in Tampa,
and at the NAS in Key West.

...THE CARIBBEAN SEA...

An upper level ridge extends from the northern Colombia, in the
part that is from 10N northward, northwestward, to the Yucatan
Channel. High level clouds are curving anticyclonically across
the open waters of the Caribbean Sea.

Rainshowers are possible in areas of broken low level to middle
level clouds.

The monsoon trough is along 09N74W in northern Colombia beyond
07N82W in the Eastern Pacific Ocean, just to the south of
Panama. Convective precipitation: possible rainshowers from 10N
southward between 77W and 79W.

24-HOUR rainfall totals in inches for the period ending at
17/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.09 in
Montego Bay in Jamaica, 0.04 in St. Thomas in the U.S.A. Virgin
Islands, 0.02 in Guadeloupe, and 0.01 in Curacao.

...HISPANIOLA...

Upper level NW 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 were being reported during the last few
observations. Santo Domingo: nearby rainshowers. La Romana:
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 NW wind flow will
move across the area, until the end of the 48-hour forecast
period. A ridge will settle across Hispaniola, with NE and NW
wind flow. The GFS MODEL forecast for 500 MB shows that NE wind
flow will move across the area, with a Cuba-to-Atlantic Ocean
anticyclonic circulation center. The GFS MODEL forecast for 700
mb shows that E-to-SE wind flow will move across the area, with
an E-to-W oriented Atlantic Ocean ridge.

...THE ATLANTIC OCEAN...

A central Atlantic Ocean upper level trough is supporting a cold
front that passes through 32N45W to 28N53W to 25N60W. The front
becomes stationary from 25N60W to 24N69W. The stationary front
is dissipating from 24N69W to 24N79W in the Bahamas. Convective
precipitation: isolated moderate within 60 nm to 90 nm on
either side of the line that passes through 32N41W to 24N53W.
Rainshowers are possible elsewhere from 20N northward from 50W
westward.

Upper level cyclonic wind flow covers the Atlantic Ocean from
12N to 27N between 30W and 55W.

A surface ridge passes through 32N31W to 27N44W to 20N65W, to
the north of Puerto Rico and the Virgin Islands, to the east and
southeast of the frontal boundary.

A 1033 mb high pressure center is near 36N62W. Surface
anticyclonic wind flow is to the north and northwest of the
frontal boundary.

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

$$
MT
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