AXNT20 KNHC 180949
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Jan 18 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 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
Caribbean Gale Warning: High pressure building north of the area
will continue to support strong to near gale force winds over
the south-central Caribbean through the middle of the week.
Overnight land breezes will allow these winds to pulse to gale
force within 90 nm off the coast of Colombia, mainly between
Cartagena and Barranquilla. Please read the latest NWS High Seas
Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.
The monsoon trough extends from the coast of Sierra Leone at
09N13W to 05N25W. The ITCZ continues from 05N25W to the coast of
Brazil near 00N48W. Scattered moderate convection is noted from
04N to 08N between 25W and 30W.
GULF OF MEXICO...
A surface ridge extends from 1021 mb high pressure over the
northwest Gulf through the Straits of Florida. Dry conditions
prevail over the northwestern portion of the basin, while
scattered showers are noted across the southeastern portion.
Recent buoy and platform observations along with scatterometer
satellite data indicated light to gentle anticyclonic winds
across most of the basin, while moderate winds are noted near the
Yucatan Peninsula. Buoy, ship and altimeter data also indicated
2 to 4 ft.
The high pressure over the northwest Gulf will shift east across
the northern Gulf through Fri. Fresh to strong southerly return
flow will set up over the NW Gulf tonight into Tue between the
high pressure and lower pressure farther west over northeast
Mexico. These winds will diminish some by mid week. This pattern
will bring relatively warm and moist are across cooler shelf
waters in the northwest Gulf, allowing the potential for sea fog
by mid week over portions of the northwest and north-central Gulf.
Farther south, a trough will form off the west coast of the
Yucatan Peninsula each night through Wed night, supporting brief
pulses of fresh to strong winds.
There is a gale warning in effect for the south-central
Caribbean. Please see the Special Features section above for
A dissipating stationary front extends across the northwest
Caribbean from central Cuba to north-central Honduras. Moderate to
fresh NE winds and 3 to 5 ft seas are noted over the northwest
Caribbean. Gale force winds and 8 to 10 ft seas are noted off
Colombia. Moderate to fresh trade winds are ongoing elsewhere across
the southeast and south- central Caribbean, with 5 to 7 ft seas.
Regional radars indicated isolated showers across the Windward
Islands, the ABC Islands and Puerto Rico. Scattered showers are
likely in the eastern part of the Yucatan Channel.
For the forecast, A stationary front reaching from eastern Cuba to the
Gulf of Honduras will dissipate this morning. High pressure
building in the wake of the front north of the region will bring
increasing winds and building seas over the southeast and south-
central Caribbean, with winds pulsing to gale force off the
coast of Colombia mainly at night through mid week. Fresh to
strong NE winds are also expected in the lee of eastern Cuba
tonight through Wed night.
West of 60W: A weakening cold front extends from near 31N54W to
27N60W where it then continues as a stationary front through
eastern Cuba and across western Caribbean. Scattered showers are
ongoing in broad swath from South Florida across the northern
Bahamas to 31N75W. These showers are ahead of a developing cold
front approaching the area from Georgia and the Carolinas.
Moderate to fresh SW to W winds are evident ahead of this boundary
over the waters north of 27N and west of 70W with 5 to 7 ft seas.
1018 mb high pressure is centered near 29N62W, supporting light to
gentle breezes north of 27N between 60W and 70W. Seas are quite
large in this area however, reaching 7 to 11 ft in lingering NW
swell. Moderate trade winds persist south of 27N with 5 to 7 ft
seas in open waters.
For the forecast, the stationary front extending from 25N65W to
eastern Cuba will dissipate today ahead of the developing
reinforcing cold front, expected to move off the NE Florida coast
later this morning. The stronger front will move rapidly east and
extend from Bermuda to central Cuba by tonight, from 24N65W to
eastern Cuba by late Tue, then stall and dissipate from 23N65W to
the Windward Passage by late Wed. Another front will move
southward into waters between NE Florida and Bermuda Wed night.
The main portion of this front will lift to the northeast of the
area Thu, leaving a trailing stationary segment to dissipate along
27N by late Thu. This will be followed by yet another front
moving southward into the waters between Bermuda and NE Florida
Farther east, the subtropical ridge supports gentle to moderate
winds over the waters north of 20N, and moderate to fresh trades
farther south. A large area of NW to N swell with significant wave
heights reaching 8 to 13 ft are active north of 22N between 30W
and 50W. Farther south, 6 to 8 ft seas prevail in a mix of N swell
and shorter period easterly wind waves.