000
AXNT20 KNHC 211203
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 AM EST SUN NOV 21 2010

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...THE ITCZ...
 
ITCZ AXIS IS ANALYZED ALONG 9N13W 6N23W 7N33W 6N39W 7N45W 5N55W. 
A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 14N45W 9N47W 
TO 6N47W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N TO 
INLAND OVER SW AFRICA E OF 4W TO JUST ACROSS THE PRIME MERIDIAN. 
SCATTERED MODERATE CONVECTION ARE FROM THE ITCZ TO 9N BETWEEN 
50W-53W. 

...DISCUSSION...

GULF OF MEXICO...
A SHALLOW SHORTWAVE UPPER TROUGH EXTENDS FROM THE NE FLORIDA 
NEAR CEDAR KEY TO NEAR 24N94W WHILE THE BROAD UPPER RIDGE 
ANCHORED IN THE CARIBBEAN COVERS THE REMAINDER OF THE GULF. 
STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT ARE NOTED ON 
SATELLITE WATER VAPOR IMAGERY ACROSS THE ENTIRE GULF BASIN. A 
BROAD SURFACE RIDGE DOMINATES THE GULF ANCHORED IN THE W ATLC. 
ISOLATED LOW LEVEL SHOWERS ARE OBSERVED N OF THE YUCATAN CHANNEL 
FROM 22N-24N BETWEEN 82W-87W AND WITHIN 45/60 NM ALONG THE 
COAST OF MEXICO IN THE BAY OF CAMPECHE FROM CAMPECHE TO VERA 
CRUZ LEAVING THE REMAINDER OF THE GULF WITH FAIR CONDITIONS 
AGAIN THIS MORNING. 

CARIBBEAN SEA...
BROAD UPPER RIDGE COVERS THE ENTIRE CARIBBEAN AND EXTENDING OVER 
THE GULF OF MEXICO AND W ATLC ANCHORED S OF PUERTO RICO NEAR 
15N67W. THIS UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO 
ENHANCE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 
ACROSS THE S CARIBBEAN S OF 15N TO THE COAST OF SOUTH AND 
CENTRAL AMERICA BETWEEN 61W-84W INCLUDING THE WINDWARD ISLANDS 
AND PORTIONS OF NICARAGUA. MODERATE/STRONG SUBSIDENCE AND DRY 
STABLE AIR ALOFT ARE NOTED ON SATELLITE WATER VAPOR IMAGERY N OF 
16N E OF 85W...ALTHOUGH THERE IS SOME RESIDUAL MOISTURE AND A 
SURFACE TROUGH THAT EXTENDS FROM THE W ATLC ACROSS CUBA NEAR 
CAMAGUEY TO 20N85W. THIS MOISTURE AND SURFACE TROUGH ARE 
GENERATING ISOLATED LOW LEVEL SHOWERS N OF 19N FROM 80W-84W 
LEAVING THE REMAINDER OF THE N CARIBBEAN WITH MOSTLY FAIR 
WEATHER TONIGHT. 

ATLANTIC OCEAN...
THE BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN EXTENDS OVER THE 
FAR W ATLC W OF 64W. BROAD UPPER LEVEL TROUGH COVERS THE 
REMAINDER OF THE W ATLC AND CENTRAL ATLC N OF 20N BETWEEN 
35W-65W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 
32N38W EXTENDING SW ALONG 24N48W TO 22N59W BECOMING A STATIONARY 
FRONT TO 21N66W THEN A SURFACE TROUGH THROUGH THE TURKS AND 
CAICOS TO 21N75W AND ACROSS CUBA NEAR CAMAGUEY INTO THE NW 
CARIBBEAN. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE 
FRONT/SURFACE TROUGH. A SURFACE TROUGH IS TO THE E OF THE FRONT 
EXTENDING THROUGH 32N34W TO 24N41W AND SCATTERED SHOWERS WITHIN 
240 NM E OF THE TROUGH. AN UPPER RIDGE IS TO THE E EXTENDING 
FROM THE TROPICS NEAR 12N29W NE TO OVER AFRICA NEAR 22N15W.  A 
WEAK SURFACE RIDGE COVERS THE REMAINDER OF THE E ATLC N OF 23N E 
OF 30W ANCHORED BY A 1018 MB HIGH JUST W OF THE CANARY ISLANDS 
NEAR 29N22W. 

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
PAW