AXNT20 KNHC 031740
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Dec 3 2020
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
Gulf of Mexico Gale Warning: A cold front off the coast of Texas
this morning will move southward into the Bay of Campeche later
today. Gales will quickly develop behind the front off the coast
of Veracruz, Mexico this afternoon and continue through tonight.
Seas will build to 12 ft. Winds will then diminish to strong by
tonight and remain fresh Fri and Sat with seas ranging 8 to 10
ft. By Sun, a coastal trough in the area may bring another round
of gale-force northerly winds offshore Veracruz and portions of
the western Bay of Campeche. Please, read the latest NWS High
Seas Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.html for more details.
The monsoon trough passes through the coastal sections of Sierra
Leone near 08N13W to 08N20W. The ITCZ continues from 08N20W to
07N33W to the coast of Brazil near 01N50W. Scattered moderate
convection is noted within 150 nm of the ITCZ between 19W and
GULF OF MEXICO...
Please see Special Features for gales developing offshore
At 03/1500 UTC, a 1017 mb low is south of the western Louisiana
coast near 29N93W. A warm front extends east of the low across
the central Gulf coast. A cold front extends south of the low to
the coast of Mexico near 20N96W. A trough is located in the Bay
of Campeche from 22N94W to the coast of southern Mexico near
18N94W. Scattered moderate convection is noted east of the cold
front in the north-central Gulf from 26N to 31N between 85W to
92W. Another area of scattered moderate convection is noted in
the central and southern Gulf from 20N to 26N between 87W to
94W. Surface ridging continues to stretch across the eastern
Gulf. An area of strong S to SE winds are ahead of the cold
front near the low. Moderate to fresh ESE winds are noted across
the rest of the basin ahead of the front. Fresh to strong N to
NW winds are in the western Gulf behind the front. Seas range 4
to 7 ft across most of the basin. Near and behind the front,
seas are 12 to 15 ft in the NW Gulf.
Ahead of the cold front, the strong SE winds in the
north-central Gulf will diminish later this afternoon. Behind
the front, strong NW winds in the western Gulf will spread
southward through the Mexican offshore waters and continue into
Fri evening. Gales will develop this afternoon off Veracruz and
continue through the evening. The slow moving cold front will
stretch from Louisiana to the Bay of Campeche tonight, the Florida
Panhandle to the west coast of the Yucatan Peninsula Fri night,
then weaken as it exits the SE Gulf Sat night. A coastal trough
will develop near the Mexican coast Sat. Building high pressure
west of the trough will induce strong N winds over the western
Gulf, with potential for gale conditions offshore Veracruz Sun.
The stationary front in the NW Caribbean extends from eastern
Cuba near 20N78W to the Yucatan Peninsula near 20N87W. Scattered
showers are within 50 nm of the front. Along and north of the
front, strong NE winds are ongoing with seas of 8 to 11 ft.
A trough stretches from the Windward Passage to the southwest
Caribbean from 19N74W to 10N81W. There is a 1009 mb low located
in the southwest Caribbean near the monsoon trough that extends
from the Colombian coast to the eastern Panama coast. Scattered
moderate convection is from 10N to 17N between 77W to 84W. Moderate
to fresh trades are occurring across the central and northwest
Caribbean. Gentle trades are noted elsewhere. Outside of the
northwest, Caribbean seas range 4 to 7 ft with upwards of 9 ft
north of Colombia.
The stationary front will weaken into tonight and dissipate Fri.
Fresh to strong winds and rough seas will prevail NW of this
front into Fri. Fresh to strong winds will also occur through Fri
across the south central Caribbean as high pressure moves E into
the western Atlantic. Looking ahead, another cold front will
approach the Yucatan Channel Sun.
A dying secondary cold front is noted from 31N65W to 26N72W. The
primary cold front continues to move eastward across the central
Atlantic, entering the waters near 31N61W and stretches southwest
to the Turks and Caicos near 22N72W. Moderate to fresh N to NE
winds are noted behind the front. Ahead of the cold front, a 1016
mb low is near 30N59W with a trough extending southeast of the low
to 28N57W. Showers are within 50 nm of the front. Another trough
is located in the central Atlantic from 26N54W to 16N51W. An area
of numerous moderate to strong convection is east of the trough
from 16N to 26N between 41W to 49W. Gentle to moderate winds are
observed across the western and central Atlantic with seas 5 to 9
ft, and 3-5 ft near the Florida coast and near the Bahamas.
In the eastern Atlantic, a weakening 1014 mb low pressure is
centered near 30N20W, about 150 nm NW of the Canary Islands.
Gale force N to NE winds are occurring N of the area, well away
from the center, closer to the Azores. These gale force winds
are expected to end by this afternoon. Scattered showers are
within 150 nm of the low. Winds associated with this low along
with northerly swell between the aforementioned troughs and this
low are leading to a broad area of 9 to 15 ft seas N of about
The cold front will drift SE through tonight, then stall and
dissipate Fri. Strong S winds will develop off the SE U.S. coast
Fri night into Sat in advance of the next cold front. The cold
front will extend from 31N75W to north-central Florida early
Sat, then from 31N65W to 26N72W and weakening to the Central
Bahamas early Sun.