Tropical Weather Discussion
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000
AXNT20 KNHC 200604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 AM EST Mon Feb 20 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through the coastal areas of Liberia
near 06N11W to 04N15W. The ITCZ continues from 04N15W, to 02N22W
02N33W, crossing the Equator along 38W, to the coast of Brazil
near 03S43W. Convective precipitation: widely scattered moderate
to isolated strong from 06N southward between 10W and 26W, and
from 06N southward between 31W and 46W.

Rainshowers are possible elsewhere from 10N to 20N between Africa
and 60W, in areas of broken low level clouds.

...DISCUSSION...

...THE GULF OF MEXICO...

A deep layer trough extends from Colorado to north central Mexico.
The trough is supporting a cold front that runs from north-to-
south, from north central Texas to north central Mexico. Return SE
wind flow spans the open waters of the Gulf of Mexico.

An upper level ridge is along 86W/87W. High level moisture is
being pushed across the open waters of the Gulf of Mexico with the
anticyclonic wind flow around the ridge.

...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: KMZG and KEIR.

IFR: KBBF, KBQX, KXIH, KHHV, KHQI, KSPR, and KATP.

MVFR: KVAF, KEMK, KGUL, KEHC, KVQT, KGHB, and KGRY.

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/IFR in the deep South of Texas. light rain and
IFR/MVFR, with smaller areas of LIFR, from the middle Texas
coastal plains to the Houston metropolitan area and surrounding
smaller communities, to Huntsville, and from Galveston to
Beaumont/Port Arthur and Jasper. LOUISIANA: LIFR around Lake
Pontchartrain. IFR/MVFR from Baton Rouge southwestward to the
coast. MISSISSIPPI: MVFR at the Stennis Airport. LIFR elsewhere to
the east of the Stennis Airport. ALABAMA: LIFR in Gulf Shores.
FLORIDA: LIFR at the NAS in Pensacola. MVFR in Mary Esther. IFR
in Panama City. LIFR in Apalachicola and from Perry to Cross City,
at the St. Pete/Clearwater International Airport, and in
Sarasota.

...FROM THE WESTERN ATLANTIC OCEAN, TO FLORIDA AND THE BAHAMAS...

The middle level-to-upper level cyclonic circulation center that
was in Virginia 24 hours ago, has moved into the western Atlantic
Ocean, near 31N72W. Cyclonic wind flow is sweeping across the western
Atlantic Ocean, and Florida and the Bahamas, with this cyclonic
center and an accompanying trough. A cold front extends from a
1012 mb low pressure center that is near 31N73W, to the NW Bahamas
and Florida near 27N80W. A dissipating cold front continues from
27N80W at the Florida coast, into the Gulf of Mexico near 28N89W.
A pre-frontal trough is along 28N71W 25N76W 26N80W. Convective
precipitation: widely scattered moderate to isolated strong from
24N northward between 64W and 72W. Rainshowers are possible also
from 23N to 27N between 70W and 80W, across the Bahamas.

...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 14N northward between 25W
and 52W. A cold front passes through 32N40W in the Atlantic
Ocean, to 25N46W 20N55W, across the NE Caribbean Sea, to Puerto
Rico, and the SE coastal sections of the Dominican Republic.
Convective precipitation: isolated moderate from 20N northward
between 30W and 50W. Rainshowers are possible also, in the
remainder of the area from 20N northward between 50W and the
western Atlantic Ocean frontal boundary.

...THE CARIBBEAN SEA...

Broad middle level-to-upper level anticyclonic wind flow spans
the entire Caribbean Sea. High level clouds are moving from the
Yucatan Peninsula, across the Greater Antilles, and into the
Caribbean Sea from 14N northward from 74W eastward.

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

Rainshowers are possible elsewhere across the Caribbean Sea, from
74W eastward, and from Jamaica westward, in areas of broken low
level clouds.

The 24-hour rainfall amounts, for the period ending at 20/0000
UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION
TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.01 in Guadeloupe.

...HISPANIOLA...

Upper level NW wind flow is moving across the area. NW wind flow
is present also 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: Barahona: VFR. few cumulonimbus clouds. Santo
Domingo/La Romana/Punta Cana: VFR. Santiago: VFR. Puerto Plato:
MVFR. ceiling 1600 feet.

The GFS MODEL forecast for 250 MB shows that NW wind flow, will
move across the area during the next 48 hours, first with a trough
and after the trough, and then being on the eastern side of a
ridge. The GFS MODEL forecast for 500 MB shows that day one will
start with SW wind flow, with an anticyclonic circulation center
that will be along to the south of Hispaniola. A trough will
follow right away, bringing NW wind flow to Hispaniola, for the
rest of day one. The first half of day two will consist of more NW
wind flow, with the trough. The second half of day two will
consist of N wind flow, as an anticyclonic circulation center
moves from Cuba to Haiti. The GFS MODEL forecast for 700 mb shows
that day one will consist of NW wind flow, being on the northern
side of an east-to-west oriented Caribbean Sea ridge. The first
half of day two will consist of N wind flow, with a trough to the
east of Hispaniola and a ridge to the west of Hispaniola. The rest
of day two will consist of NE wind flow, as the ridge moves closer
to Hispaniola.

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


Broad upper level cyclonic wind flow covers the Atlantic Ocean
from 20N northward from 25W eastward. An upper level cyclonic
circulation center is near 33N09W at the coast of Morocco.

A surface ridge passes through 32N30W, to 28N34W, 26N33W, to
12N33W. A 1022 mb high pressure center is near 30N65W. Surface
anticyclonic wind flow covers the Atlantic Ocean to the northwest
of the central Atlantic Ocean cold front, and to the east of the
western Atlantic Ocean frontal boundary.

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

$$
MT



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