AXNT20 KNHC 120559
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 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 0000 UTC surface analysis and satellite imagery through
Gale Warning E of 35W: The surface pressure gradient, between
the Atlantic Ocean ridge, and comparatively lower pressures in
Africa, will be supporting gale-force winds, off the coast of
Agadir, in Morocco. The Meteo-France high seas forecast consists
of northerly winds of Force 8, until 13/0000 UTC. Please, refer
to the Meteo-France High Seas Forecast, that is listed on the
marine/bulletin/grandlarge/metarea2, for more details.
The monsoon trough passes through the coastal plains of Sierra
Leone near 07N12W, to 05N13W, and 03N17W. No ITCZ was
discernible. A surface trough is along 23W/25W from the Equator
to 05N. A surface trough is to the south of the Equator along
04S32W, 02S35W, at the Equator along 39W. Precipitation: widely
scattered to scattered moderate, and isolated to widely
scattered moderate, are from 05N southward between 43W and 52W.
Isolated moderate to locally strong is from 08N southward from
GULF OF MEXICO...
A surface trough passes through south central Georgia, through
the Florida Big Bend, into the north central Gulf of Mexico, to
the eastern coastal waters of Louisiana. An inland stationary
front is passing through central Louisiana. Precipitation:
numerous strong is in SE Louisiana.
A cold front is in south central Texas. Precipitation: numerous
strong is in the coastal waters of Texas and in northern Mexico
adjacent to Texas, within 150 nm to the south of the cold front
between 95W and 100W.
Fresh SE winds are within 100 nm to 150 nm to the NW of the NW
coast of the Yucatan Peninsula. A surface trough extends from
the NW corner of the Yucatan Peninsula, southwestward, to the
northern part of the Isthmus of Tehuantepec of southern Mexico.
Moderate to locally fresh southerly winds are across the western
Gulf of Mexico. Gentle to moderate E to SE winds prevail in the
eastern half of the Gulf of Mexico. Building high pressure in
the SE CONUS will push a late-season cold front across the Gulf
on Wednesday. The cold front is expected to extend across the
Straits of Florida and the southern Gulf of Mexico by late
Friday. Fresh to strong northerly winds will follow the front.
An upper level trough extends from the SE Bahamas, through the
Windward Passage, across Jamaica, to the east central coast of
Nicaragua. Comparatively drier air in subsidence is within 100
nm on either side of the upper level trough. Upper level
moisture is curving northeastward in the Caribbean Sea, to the
east and southeast of the comparatively drier air that is around
the upper level trough. Precipitation: widely scattered moderate
to isolated strong is in the southern half of Nicaragua.
The monsoon trough passes through 11N74W in northern Colombia,
through the border of Colombia and Panama, beyond 07N80W, into
the eastern Pacific Ocean. Precipitation: numerous strong is
within 75 nm on the NW side of the monsoon trough between 76W
and 78W, and within 135 nm on the SE side of the monsoon trough
between 74W and 79W. The precipitation covers the waters that
are between Colombia and Panama including in the Gulf of Uraba,
and inland sections of northern Colombia. Scattered to numerous
strong is within a 30 nm radius of the western coast of Panama
E to NE strong winds cover the Caribbean Sea from 18N southward
between 66W and 81W. The sea heights in the same area are
ranging from 8 feet to 9 feet. Fresh-to-strong easterly winds
are within 135 nm to the north of the coast of Honduras from 86W
westward, to the coasts of Belize and Mexico. Expect sea heights
to be reaching a maximum of 5 feet to 6 feet in the same area as
the fresh-to-strong easterly winds.
Rainshowers are possible, elsewhere, in the areas of scattered-
to-broken low level clouds, that are moving with the surface-to-
low level wind flow.
High pressure, located to the N of the Caribbean Sea, combined
with the Colombia low pressure, will support fresh to strong
winds in the south central Caribbean Sea through Friday. Fresh
to strong winds are expected also in the Gulf of Honduras
tonight and again on Wednesday night.
High level clouds are moving from Florida, eastward, into the
Atlantic Ocean, from 24N northward from 70W westward.
A surface ridge extends from a 1027 mb high pressure center that
is near 33N21W, to a second 1027 mb high pressure center that is
near 32N38W, to a 1026 mb high pressure center that is near
31N55W, to 30N60W, to 26N74W, toward south Florida. Broad
surface anticyclonic wind flow covers the Atlantic Ocean from
20N northward from the eastern coast of the U.S.A., eastward.
A surface ridge dominates the forecast waters. A cold front will
move southward across the western Atlantic Ocean on Wednesday.
Weak low pressure is expected to develop along the frontal
boundary, allowing the front to move across the northern
forecast waters on Thursday and Friday, reaching the waters S of
27N on Saturday. High pressure will follow the front.