Tropical Weather Discussion
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000
AXNT20 KNHC 191103
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
702 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 0600 UTC surface analysis and satellite imagery through
1045 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 area that is called: AGADIR.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 51W/52W from 10N
southward, moving westward 15 knots. Convective precipitation:
isolated moderate from 10N southward between 43W and 53W.

A Caribbean Sea tropical wave is along 67W/68W from 12N southward
into Venezuela, moving westward 10 to 15 knots. Convective
precipitation: widely scattered moderate to isolated strong from
04N to 06N between 63W and 66W, inland. isolated moderate
elsewhere in Venezuela from 04N to 10N from 64W westward.

A Caribbean Sea tropical wave is along 82W 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 Senegal
near 15N17W, to 12N20W, and 06N28W. The ITCZ continues from
06N28W to 01N38W. Convective precipitation: scattered strong from
04N to 06N between 22W and 26W. Widely scattered moderate to
isolated strong from 05N to 07N between 30W and 35W. Isolated
moderate elsewhere from 10N southward from 60W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level westerly wind flow spans the area. Some of the wind
flow that is in the NW corner is from the SW. Some of the wind
flow that is in the central part of the Gulf of Mexico from west
to east is NW, hinting at some anticyclonic wind flow, in the
central and NE sections. High level moisture is within 120 nm on
either side of a line from the Florida Panhandle, into the central
Gulf waters, to the Mexico coast near 24N.

A surface ridge extends from the NW corner of the area toward 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, KEMK, KHQI, KVQT, KGRY, KEIR, 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...

ALABAMA: 4 and mist in Evergreen. FLORIDA: Cross City: 5 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 is along 85W/86W from 16N at the coast of
Honduras to 25N in the SE Gulf of Mexico. Convective
precipitation: isolated moderate between 77W and 84W. Broken to
overcast multilayered clouds and other possible rainshowers cover
the Caribbean Sea from 13N to 20N between 60W and 80W. Please
monitor any advisories and bulletins from local meteorology
offices, emergency management services, and other governmental
agencies.

...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 falling
apart with time. The southern part of the trough has been filling
and drifting 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 has been 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: MVFR. for the
DOMINICAN REPUBLIC: Barahona: VFR. few cumulonimbus clouds. Santo
Domingo: VFR. La Romana and Punta Cana: VFR. Santiago and 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 32N33W, to 28N40W and
21N44W. A cold front passes through 32N45W to 31N47W. Convective
precipitation: broken to overcast multilayered clouds and possible
rainshowers cover the area from 20N to 30N between 30W and 60W,
and from 20N to 26N between 60W and 80W.

A surface ridge extends from a 1028 mb high pressure center that
is near 41N20W through 32N33W, to 28N47W. A 1023 mb high pressure
center is near 32N54W. A second 1023 mb high pressure center is
near 32N60W. Surface anticyclonic wind flow covers the Atlantic
Ocean from 16N northward between 50W and 80W.

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

$$
MT



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