Tropical Weather Discussion
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000
AXNT20 KNHC 190601
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
201 AM EDT Fri May 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...

Please refer to the METEO-FRANCE High Seas Forecast, that is
listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO-
MARINE/BULLETIN/GRANDLARGE/METAREA2. Gale-force winds are
forecast for the areas that are called: AGADIR and CANARIAS.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 13N45W 08N47W 02N48W,
moving westward 10 to 15 knots. Convective precipitation:
isolated moderate from 10N southward between 40W and 50W.

A Caribbean Sea tropical wave is along 66W from 12N southward
into Venezuela, moving westward 10 to 15 knots. Convective
precipitation: isolated moderate in Venezuela between 62W and 67W.

A Caribbean Sea tropical wave is along 81W from 17N southward,
moving westward 10 knots. This wave is moving through the area of
an upper level trough, whose cyclonic wind flow covers the
Caribbean Sea from 80W westward. Convective precipitation: any
precipitation is in the area of the larger-scale cyclonic wind
flow that accompanies the upper level trough.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through coastal sections of Mauritania
near 17N16W, to 13N20W, and 06N28W. The ITCZ continues from
06N28W to 03N40W, to 01N50W at the coast of Brazil. Convective
precipitation: scattered to numerous strong from 08N to 10N
between 14W and 16W, and from 06N to 08N between 20W and 24W.
Isolated moderate elsewhere from 07N southward from 35W eastward.
Rainshowers are possible remainder of area from 10N southward from
60W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level W and SW wind flow spans the entire Gulf of Mexico.
High level clouds are to the NW of the line from 29N83W at the
Florida west coast, to 24N90W, to the coast of Mexico along 22N.
Numerous strong convective precipitation in interior Mexico covers
the area from 18N to 20N between 97W and 99W. Comparatively
drier air in subsidence is apparent in water vapor imagery
elsewhere, to the east of the high level cloudiness.

A surface ridge extends from the NW corner of the area into the
SW corner of the Gulf of Mexico.

...VISIBILITY IN MILES, AND WEATHER, FOR THE OFFSHORE OIL
PLATFORM SITES, THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

KMZG, KBBF, and KVOA: 2 to 3, and mist.
KXIH, KHHV, KVAF, KEMK, KGUL, KHQI, KGBK, KVQT, KGHB, KGRY, KEIR,
KSPR, and KMDJ: 3 TO 5 and mist. KVOA: 3 to 5 and haze.

VISIBILITY IN MILES, AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

FLORIDA: Milton: 1 and mist. Crestview: 4 and mist.

...THE CARIBBEAN SEA...

An upper level trough remains from NW Cuba, to a 19N82W NW
Caribbean Sea cyclonic circulation center, to southern Nicaragua/
Costa Rica. Upper level anticyclonic wind flow covers the rest of
the Caribbean Sea that is to the east of the persistent trough. A
surface trough extends from the Florida Keys, across NW Cuba, to
20N84W in the NW corner of the Caribbean Sea. Convective
precipitation: isolated moderate to locally strong from 19N to 22N
between 79W and 83W in the NW corner of the Caribbean Sea, to the
south of Cuba. Isolated moderate elsewhere, from 13N to 20N
between the Mona Passage and 84W. Please monitor any advisories
and bulletins from local meteorology offices, emergency management
services, and other governmental agencies. Convective
precipitation: isolated moderate to locally strong also from 10N
southward from 80W westward, along the coast of Panama. Isolated
moderate at the coast of Colombia from 11N to 12N between 73W and
74W.

...HISPANIOLA...

Upper level anticyclonic wind flow is moving across Hispaniola.

The persistent upper-level trough, that has been situated in
the NW Caribbean Sea during the last several days, has begun to
fracture. The southern part of the trough is beginning to fill
and drift westward. The deep convective precipitation has been
weakening and dissipating. Some drying between 800 mb and 500 mb
was noted on the 18/1200 UTC Santo Domingo rawinsonde, suggesting
that some dry air was making its way into Hispaniola and Haiti.
It appears that the heavy rainfall threat may be shifting to
Jamaica and the NW Caribbean Sea during the next 24 hours or so,
per the NWP model guidance and recent trends, Please monitor
advisories and bulletins from local meteorology offices, emergency
management services, and other governmental agencies.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the
DOMINICAN REPUBLIC: Barahona: VFR. few cumulonimbus clouds. Santo
Domingo: VFR. earlier cloud ceilings at 1800 feet have cleared up
for the moment. La Romana and Punta Cana: VFR. Santiago: VFR. few
cumulonimbus clouds. Puerto Plata: VFR.

The GFS MODEL forecast for 250 mb shows that SW wind flow will
shift to westerly, and then to NW by the end of the first 24 hours
of the 48-hour forecast period. Expect NW wind flow during day
two. The GFS MODEL forecast for 500 mb shows that SW wind flow
will last for the first 6 hours to 12 hours, with an E-to-W
oriented Atlantic Ocean-to-Caribbean Sea ridge. Cyclonic wind flow
will move across Hispaniola for the next 30 hours, with an
Atlantic Ocean-to-Hispaniola trough. Anticyclonic wind flow starts
to push out of the way the cyclonic wind flow, from north-to-south
across Hispaniola, with an Atlantic Ocean-to-Hispaniola ridge,
during the 6 hours to 12 hours of the forecast period. The GFS
MODEL forecast for 700 mb shows that Hispaniola will be on the
western side of an Atlantic Ocean anticyclonic circulation center
during the next 48 hours. Expect mostly SE wind flow, with a bit
of E wind flow, during the forecast period.

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

An upper level trough passes through 32N34W, to 29N40W and 22N45W.
A cold front passes through 32N45W to 31N48W. Convective
precipitation: broken to overcast multilayered clouds and
possible rainshowers cover the area from 20N to 28N between 30W
and 80W.

A surface ridge extends from a 1030 mb high pressure center that
is near 41N22W through 32N37W, to 28N50W. A 1024 mb high pressure
center is near 32N55W. A second 1024 mb high pressure center is
near 32N64W. Surface anticyclonic wind flow covers the Atlantic
Ocean from 16N northward between 55W and 80W.

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

$$
MT



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