Tropical Weather Discussion
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000
AXNT20 KNHC 211802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
102 PM EST Sat Jan 21 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
1645 UTC.

...SPECIAL FEATURES...

...GALE WARNING FOR THE GULF OF MEXICO...

The 24-hour forecast consists of a cold front 29N91W to 22N97W.
Expect W-to-NW gale-force winds, and sea heights ranging from 9
feet to 11 feet, to the N of 27N to the W of the front.

...GALE WARNING FOR THE ATLANTIC OCEAN...

The 36-hour forecast consists of a cold front that will be
approaching the area from the west. Expect SW gale-force winds,
and sea heights ranging from 11 feet to 13 feet, from 28N to 31N
to the west of 77W.

Please read the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through Liberia near 06N10W to 04N12W
and 05N14W. The ITCZ continues from 05N14W to 05N17W 01N33W, to
the equator along 41W. Convective precipitation: Scattered strong
from 06N southward between 07W and 15W. Isolated moderate
elsewhere from 10N southward between Africa and 60W.

...DISCUSSION...

...THE GULF OF MEXICO...

Middle level-to-upper level anticyclonic wind flow covers the
Gulf of Mexico from 90W eastward. A ridge is along 78W/79W.

A middle level to upper level trough is moving into the central
sections of the Gulf of Mexico. The trough now passes through
Louisiana, into the SW corner of the Gulf of Mexico. A stationary
front runs from central Alabama, through southern Louisiana, into
south central Texas.

Rainshowers and thunderstorms will accompany a strong cold front,
that is forecast to move into the northwestern part of the Gulf of
Mexico tonight, on Saturday night. The front will reach from the
Florida Big Bend into the SW corner of the Gulf of Mexico by early
on Sunday afternoon. The front is forecast to be passing through
NE Florida, to the Yucatan Channel by early on Monday morning.
Gale-force winds are possible behind the front from Sunday
morning through Monday in the northern and central sections of the
Gulf of Mexico, possibly spilling into the southeastern Gulf of
Mexico, with seas building as high as 16 to 19 ft. Conditions will
improve gradually from west to east Monday night through Tuesday
night as high pressure builds in behind the front.

...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: KVBS with fog.

IFR: KHHV, KVAF, KGUL, KEHC, KSPR, KIKT, KMIS, and KDLP, with
mist at all the locations.

MVFR: KMZG, KBBF, KBQX, KXIH, KEMK, KHQI, KVQT, KGHB, KGRY, KATP,
KEIR, KMDJ, KVOA with mist at all the locations.

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 Weslaco. IFR in Palacios. MVFR has cleared for the
moment in Bay City and in Angleton/Lake Jackson. IFR from
Beaumont/Port Arthur to Jasper. MVFR from Galveston to the Houston
metropolitan area and Sugar Land. IFR in Conroe and Huntsville.
LOUISIANA: MVFR in the southernmost sections of the state. IFR in
the SE corner. MISSISSIPPI: rain and thunder in parts of the
Hattiesburg metropolitan area. ALABAMA: rain and thunder in
southern sections/coastal sections. FLORIDA: rain and thunder from
Marianna westward. MVFR in the NW part of the Pensacola
metropolitan area and in Tallahassee.

...THE CARIBBEAN SEA...

Middle level-to-upper level NW wind flow covers the Caribbean Sea
from Haiti eastward. Middle level-to-upper level anticyclonic
wind flow covers the NW corner of the area.

Upper level wind flow is curving anticyclonically, from the
eastern Pacific Ocean into the Caribbean Sea, between 73W and
Nicaragua.

Rainshowers are possible from 15N northward from 80W eastward.
Surface anticyclonic wind flow spans the area.

24-HOUR rainfall amounts, for the period ending at 21/1200 UTC...
according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION
TABLES...MIATPTPAN/SXCA01 KNHC...are 0.25 in Trinidad, and 0.02 in
Curacao.

...HISPANIOLA...

Upper level NW wind flow is moving across Hispaniola.
Comparatively drier air in subsidence is apparent in water vapor
imagery, across the entire area. Rainshowers are possible along
the NE coast of The Dominican Republic between the Mona Passage
and 70W.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the
DOMINICAN REPUBLIC: Barahona: VFR. Santo Domingo/La Romana/Punta
Cana: VFR. Santiago/Puerto Plata: VFR.

The GFS MODEL forecast for 250 MB shows that NW wind flow will
move across the area during the next 48 hours, with a N Colombia-
to-Yucatan Peninsula ridge. The GFS MODEL forecast for 500 MB
shows that northerly wind flow will move across the area during
the next 36 hours, with a trough to the east and an anticyclonic
circulation center to the west. An anticyclonic circulation center
will move through the southern sections of the island after 36
hours, and then the center will move toward Puerto Rico. Expect SW
wind flow for the rest of the time period. The GFS MODEL forecast
for 700 mb shows that northerly wind flow will move across
Hispaniola during the next 30 hours. An Atlantic Ocean
anticyclonic circulation will move NE, pushing southerly wind flow
across Hispaniola for the rest of the 48-hour forecast period.

...THE ATLANTIC OCEAN...

A deep layer central Atlantic Ocean trough is supporting a cold
front that passes through 32N42W to 25N50W and 21N60W, into the
Mona Passage. Convective precipitation: widely scattered moderate to
isolated strong from 29N northward between 35W and 46W.  nm on
either side of 26N51W 29N49W 32N47W. Isolated moderate elsewhere
from 20N northward between 40W and 50W. Rainshowers are possible
elsewhere in the Atlantic Ocean from 20N northward between 40W
and 70W.

A surface ridge, that is to the east of the central Atlantic
Ocean cold front, extends from a 1028 mb high pressure center that
is near 33N26W, to 24N53W, and to 16N51W.

A 1018 mb high pressure center is near 24N74W in the Bahamas.
Surface anticyclonic wind flow covers the areas that are from 14N
to 30N between 60W and 83W, away from the Atlantic Ocean cold
front, in the Atlantic Ocean, in the Caribbean Sea, and in the
Gulf of Mexico.

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

$$
MT


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