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494
AXNT20 KNHC 191139
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
639 AM EST Sun Feb 19 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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through the coastal areas of Sierra
Leone near 07N12W to 04N14W. The ITCZ continues from 04N14W, to
02N24W, and to the Equator along 32W. Convective precipitation:
Scattered moderate to strong from 01N to 04N between 24W and 29W,
from 02N to 04N between 30W and 35W, and from the Equator to 03N
between 36W and 41W. Rainshowers are possible elsewhere from 10N
southward from 60W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

A middle level-to-upper level cyclonic circulation center is in
Virginia. Cyclonic wind flow covers the Gulf of Mexico from 25N
northward. Upper level SW wind flow is present elsewhere. A middle
level-to-upper level ridge is along 71W/72W. A stationary front
passes through north central Texas, to southern Louisiana, to the
Florida Panhandle. Convective precipitation: low clouds and fog,
areas of low visibilities, and possible rain, are moving across
Florida, from Lake Okeechobee to 30N.

...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: KEIR and KSPR.

IFR: KMZG, KBBF, KXIH, KEMK, KGUL, and KATP.

MVFR: KHHV, KVAF, KEHC, KHQI, KVQT, KGHB, KGRY 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, at a minimum, everywhere along the Texas Gulf coast
and in the coastal plains. LIFR/IFR from Bay City and Angleton/
Lake Jackson northward. LOUISIANA: LIFR in the southern half of
the state, to the coastal plains and around Lake Pontchartrain.
MISSISSIPPI: LIFR from Natchez-to-Hattiesburg southward to the
coast. ALABAMA: LIFR from Evergreen-to-Dothan southward to the
area that is between Florida and Mississippi. FLORIDA: Mostly
LIFR/some IFR Cross City westward, and from Cross City to
Sarasota. MVFR in Punta Gorda. LIFR/IFR in the Ft.Myers
metropolitan area. MVFR in Naples.

...FROM THE CENTRAL ATLANTIC OCEAN, INTO THE WINDWARD PASSAGE...

Deep layer cyclonic wind flow, with a central Atlantic Ocean
trough, covers the Atlantic Ocean from 20N northward between 40W
and 70W. A cold front passes through 32N45W in the Atlantic
Ocean, to 24N50W 20N60W, and 19N67W just to the north of Puerto
Rico. Remnant clouds from the already-dissipated part of the cold
front, and possible rainshowers, cover the Caribbean Sea from 17N
to 20N between the Mona Passage and Jamaica. Other convective
precipitation: widely scattered moderate to isolated strong in
the Atlantic Ocean within 30 nm to 60 nm on either side of the
line that passes through 32N43W to 27N45W to 23N49W. Rainshowers
are possible elsewhere within 240 nm to the W and NW of the line
that passes through 30N41W 23N47W 20N57W and 18N67W near Puerto
Rico, and in the remainder of the area from 10N northward between
30W and 60W.

...THE CARIBBEAN SEA...

Broad middle level-to-upper level anticyclonic wind flow spans
the entire Caribbean Sea. High level clouds are moving through the
NW corner from 14N northward from Jamaica westward, and across
the Greater Antilles.

Comparatively drier air in subsidence is apparent in water vapor
imagery elsewhere across the area.

Rainshowers are possible elsewhere across the Caribbean Sea, from
17N southward from 80W eastward, and from 20N southward between
80W and 85W, in areas of broken low level clouds.

The 24-hour rainfall amounts, for the period ending at 19/0000
UTC... according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION
TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.02 in Guadeloupe.

...HISPANIOLA...

Upper level NW wind flow is moving across the area. NE-to-E wind
flow is present from 600 mb to 800 mb. Comparatively drier air in
subsidence is apparent in water vapor imagery across Hispaniola.
Convective precipitation: Rainshowers are possible inland, and in
the coastal waters.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti, VFR. for the
DOMINICAN REPUBLIC: Santo Domingo: MVFR. ceiling 1800 feet. few
cumulonimbus clouds. La Romana: light rain. Punta Cana: light
rain. MVFR. ceiling 1600 feet. Santiago/Puerto Plato: VFR.

The GFS MODEL forecast for 250 MB shows that NW wind flow, with a
ridge, will move across the area during the first 30 hours of the
48-hour forecast period. NW wind flow, with a trough, will move
across Hispaniola during the rest of the time. The GFS MODEL
forecast for 500 MB shows that day one will start with an
anticyclonic circulation center that will be along the south
central coast of the Dominican Republic. The anticyclonic center
will move to the south of Hispaniola, spreading westerly wind flow
across the area, for the rest of day one. A trough will approach
Hispaniola from the northwest. The trough will move across the
area, leaving more NW and N wind flow for Hispaniola during day
two. The GFS MODEL forecast for 700 mb shows that day one will
start with an anticyclonic circulation center along the northern
coast of Hispaniola, followed by a col point across the area for
12 hours or so, followed by anticyclonic wind flow with the
eastern end of an east-to-west oriented ridge. Expect NW-to-N wind
flow with a ridge, for day two.

...THE REST OF THE ATLANTIC OCEAN...

A surface ridge passes through 32N30W, to 28N34W, 23N40W, 20N47W,
and 17N66W. A 1022 mb high pressure center is near 28N65W.
Surface anticyclonic wind flow covers the Atlantic Ocean to the
northwest of the cold front.

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

$$
MT



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