Tropical Weather Discussion

- as issued by NHC/TPC -

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Tropical Weather Discussion (NHC/TPC):
NWS National Hurricane Center Miami FL
0005 UTC Wed Nov 25 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 1800 UTC surface analysis and satellite imagery through 
2030 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis passes through the northern coastal 
sections of Guinea near 10N14W to 05N24W. The ITCZ axis 
continues from 05N24W to 06N38W to the coast of far NW Brazil 
near 04N51W. Scattered moderate and isolated strong convection 
is noted from 04N-09N between 13W-17W, from 04N-07N between 35W-
40W, from 09N-12N between 35W-40W, and from 07N-10N between 57W-
61W.

GULF OF MEXICO...

A cold front extends from along the southern Mississippi River 
to near Shreveport, Louisiana to near Baffin Bay, Texas. A 
prefrontal squall line is noted on radar from near New Orleans, 
Louisiana to across south-central Louisiana into the southwest 
Louisiana coastal waters. Scattered moderate to strong 
convection is within 30 nm of the squall line. Elsewhere, 
scattered showers are over South Florida and the southeastern 
Gulf, extending northwest to the northeastern Gulf. Moderate to 
locally fresh SE return flow prevails across the basin late this 
afternoon, except shifting moderate northerly winds behind the 
cold front.

High pressure over the eastern Gulf will gradually shift 
eastward as a the cold front moves east-southeast the northern 
Gulf waters tonight. The front will stall and lift northward on 
Thu. A weak cold front may move into the north-central and 
northeast Gulf coastal waters Fri night, stalling through Sat. A 
strong cold front will move into the northwest Gulf waters Sun 
morning returning fresh to strong northerly winds across the 
basin behind it. The front is forecast to shift southeast of the 
basin Mon night.

CARIBBEAN SEA...

Scattered moderate convection is along the coast and just 
offshore from Colombia to Panama northward to Honduras. 
Elsewhere, scattered showers are over the Virgin Islands, Puerto 
Rico, and Hispaniola mostly due to the now dissipated tail end 
of a cold front over the W Atlantic. Fresh to strong NE-E flow 
is noted south of Hispaniola to 15N, northwest of the coast of 
Colombia, and across the Windward Passage due to building high 
pressure north of the area and lower pressure over northern 
Colombia and the southwest Caribbean Sea. Moderate to fresh 
trades prevail elsewhere. Seas are 6-8 ft across the areas of 
fresh to strong winds, and mainly 4-6 ft elsewhere.

The fresh to strong winds in the central Caribbean will persist 
through Thu. Moderate to fresh trade winds will prevail across 
most of the area Thu night into early next week. Looking ahead, 
a cold front may move southeast of the Yucatan Channel into the 
northwest Caribbean Mon through Mon night.

ATLANTIC OCEAN...

A cold front extends from 32N55W to a 1016 mb low pressure area 
near 31N56W to another low pressure area 1015 mb near 26N59W to 
north of the Virgin Islands near 21N64W. Scattered moderate and 
isolated strong convection is noted north of 21N between 47W-
57W. A 1036 mb high is centered well north of the area southeast 
of Nova Scotia near 44N59W. This high extends a ridge 
southwestward to across the Florida Peninsula. Fresh to strong 
winds are noted west of the front to 65W due to a tight pressure 
gradient between the ridging and low pressure areas along the 
front. Moderate to fresh winds prevail elsewhere under the ridge 
and behind the front. Seas are 8-13 ft across the area of fresh 
to strong winds, and 6-10 ft elsewhere west of the front, except 
3 ft or less west of the Bahamas. A 1034 mb high is centered 
over the Azores near 38N31W. This high and attendant ridging 
dominates the remainder of the waters north of the ITCZ and east 
of the cold front.

The cold front over the central Atlantic will shift slowly 
eastward this evening, then become stationary by Thu. The fresh 
to strong winds just west of the front will prevail through Thu. 
The large seas in northerly swell behind the front is expected 
to continue to impact the Atlantic waters and Caribbean passages 
through Fri. The stalled out front will linger into the weekend, 
becoming a remnant trough. A weak backdoor cold front may drop 
south of 31N late Sat night into Sun, stalling and dissipating 
along 27N by Sun evening. A stronger cold front will move into 
the waters off the southeast U.S. coast Mon through early next 
week.

$$
Graphical representation of waves, etc. on this image (NCEP/OPC) [more].
Various tropical satellite imagery available here

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