Skip Navigation Links
NOAA NOAA United States Department of Commerce

Atlantic Tropical Weather Discussion

AXNT20 KNHC 120038

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Wed May 12 2021

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 
2220 UTC.

...Special Features...

Gale Warning E of 35W: The pressure gradient between the Atlantic
ridge and lower pressures over W Africa will support fresh to 
strong winds N of 20N and within about 150 nm of the coast of W 
Africa off Agadir, Morocco. Meteo-France has continued a Gale 
Warning for Agadir from 11/18Z through 13/00Z. The forecast calls
for northerly winds Force 8 in the Beaufort Wind Scale with 
gusts and at times very rough seas. For more details, refer to 
the Meteo- France High Seas Forecast listed on their website: meteo- 


The monsoon trough enters the Atlantic Ocean through the coast 
of Guinea-Bissau near 12N16W to 07N17W. The ITCZ continues from 
07N17W to 00N35W to the coast of Brazil near 01S47W. Scattered 
moderate to strong convection is along and south of the monsoon 
trough from 03N to 07N between 16W to 21W. Scattered moderate 
convection is along the monsoon trough and ITCZ from 00N to 09N 
between 20W to 30W and from 02S to 03N between 35W to the coast 
of Brazil. 


Weak high pressure is centered over the eastern Gulf, south of a
stalled front reaching from the Sabine River to Mobile Bay. A few
thunderstorms are evident south of the front off the western
Florida Panhandle. Moderate to fresh SE winds and 4 to 6 ft seas
are noted over the western Gulf, and light to gentle breezes with
2 to 4 ft are noted over the eastern Gulf. 

For the forecast, the high pressure will dominate the Gulf waters
tonight producing moderate to locally fresh southerly winds 
across the western half of the Gulf and gentle to moderate E to SE
winds over the eastern half. A surface trough will develop over 
the Yucatan Peninsula each evening and dissipate over the SW Gulf 
by morning. Moderate to fresh easterly winds will be associated 
with this trough. A frontal boundary will linger across the 
northern Gulf coast tonight. Building high pressure across the SE 
CONUS will push a late-season cold front across the Gulf on Wed, 
and it is expected to extend across the Straits of Florida and the
southern Gulf by late Fri. Fresh to strong northerly winds will 
follow the front. 


A recent scatterometer pass indicated fresh to strong trade winds
across most of the Caribbean south of 18N, between a relatively
strong subtropical ridge centered over the central Atlantic, and
lower pressure farther south in the tropics. The high winds are
over the south-central Caribbean, with 7 to 10 ft seas. Seas are 5
to 7 ft over the eastern Caribbean. Surface observations also 
confirm fresh to strong E winds over the Bay Islands of Honduras 
as well. Gentle to moderate E winds are noted elsewhere over the 
northwest Caribbean, with 3 to 5 ft seas. A sharp upper trough 
reaches from above the Windward Passage to the far southwest 
Caribbean. Ample moisture along with trade wind convergence and 
divergence aloft east of the upper trough are together supporting 
a few thunderstorms from off western Panama to southeast Nicaragua.

For the forecast, the high pressure located north of the Caribbean
Sea combined with the Colombian low will continue to support 
fresh to strong winds over the south- central Caribbean through 
Fri. Fresh to strong winds are also expected in the Gulf of 
Honduras tonight and again Wed night. 


See the Special Features section for more information on the 
Gale Warning near Agadir. 

A ridge extends from 1025 mb high pressure centered near 30N57W to
east-central Florida. Recent buoy observations and an earlier 
scatterometer satellite pass indicated moderate to fresh trade
winds south of 22N west of 65W, with locally strong E winds off
the mountainous terrain of the central coast of Hispaniola. Seas
are estimated to be 4 to 6 ft in this area. Light to gentle 
breezes and 3 to 5 ft seas are evident elsewhere west of 65W. No
significant convection is noted west of 65W. 

Farther east, the ridge extends across the Atlantic north of 20N.
Moderate to fresh trade winds are noted south of 20N, with gentle
to moderate E winds north of 20N, except for fresh to strong NE
winds off northwest Africa. Seas are 5 to 7 ft overall.

For the forecast for the waters west of 65W, a cold front will 
move southward across the western Atlantic on Wed. Weak low 
pressure is expected to develop along the frontal boundary 
allowing the front to move across the northern forecast waters Thu
and Fri, reaching the waters S of 27N on Sat. High pressure will 
follow the front.