Tropical Weather Discussion
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AXNT20 KNHC 131649

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1248 PM EDT Sun May 13 2018

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
1715 UTC.


Please refer to the METEO-FRANCE High Seas Forecast, that is
forecast for AGADIR until 14 May at 1200 UTC.


The monsoon trough passes through the coastal sections of Sierra
Leone near 07N12W to 04N16W. The ITCZ continues from 04N16W to
01N30W to the coast of Brazil near 00N50W. Scattered moderate
convection is from 02N-05N between 00W-07W, and from 04N-06N
between 13W-16W. Scattered showers are from 00N-04N between 24W-



A 1022 mb high is centered over N Alabama near 34N86W producing
10-15 kt E to SE surface winds over the Gulf of Mexico. A surface
trough is over Florida from 28.5N80W to the Straits of Florida
near 23N82W. Radar imagery shows widely scattered moderate
convection over S Florida, the Straits of Florida, and W Cuba, due
to the surface trough.

The surface trough will amplify over the SE Gulf today. Low
pressure will develop along the trough W of Florida on Monday
and move NW, moving inland over the SE United States by midweek.
Showers and thunderstorms will affect the Gulf waters near and E
of the low.


10-25 kt tradewinds are over the Caribbean with strongest winds
along the coast of N Colombia, and weakest winds over the NW
Caribbean. Scattered moderate convection is over the NW Caribbean
mostly S of W Cuba. The Monsoon Trough is along 08N passing from
the eastern Pacific Ocean to Costa Rica to Panama to northern
Colombia. Scattered moderate convection is over the SW Caribbean S
of 11N. In the upper levels, a large ridge is over the Caribbean
with axis from Costa Rica to Haiti. A good amount of upper level
moisture is over this area. In contrast, strong subsidence is over
the SE Caribbean and the Windward Islands.

Fresh to strong trade winds will prevail in the south central
Caribbean Sea through Thursday. NE swell will maintain sea heights
about 8 feet in the southern part of the tropical N Atlantic
Ocean forecast waters until Monday.


A surface trough over the W Atlantic extends from 32N78W to
central Florida near 28.5N80W. Scattered showers are within 180
nm of the trough. Broken to overcast multilayered clouds are
elsewhere N of 20N and W of 70W. A 1026 mb high is centered over
the central Atlantic near 31N51W. A surface trough is over the E
Atlantic from 32N40W to 26N39W.

An upper level trough is over the central Atlantic N of 25N
between 50W-60W with scattered showers. An upper level low is
centered over the E Atlantic near 31N33W with scattered showers.

The current W Atlantic surface trough will shift W over Florida
and the SE Gulf of Mexico today and tonight. A high pressure ridge
E of the trough will maintain moderate winds N of 25N and fresh
winds S of 25N through Thu. Low pres over the NE Gulf of Mexico
will tighten the pressure gradient over the waters N of the
Bahamas from 27N-29N between 77W-79W on Mon night. Strong SE winds
are expected during this time frame over this area as a result.
Winds N of Hispaniola will pulse from fresh to strong from
afternoon to late evening each day through Thu. The area of strong
winds N of Hispaniola will expand northward to as far as 23N by
Sat as the high pressure ridge over the western Atlantic gradually
strengthens and low pressure over northern South America deepens

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