000
AXNT20 KNHC 172346
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST FRI DEC 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...ITCZ...
ITCZ AXIS IS ANALYZED ALONG 5N8W 6N17W 5N26W 6N37W EQ48W. A 
WEAK SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ EXTENDING FROM 
8N45W TO 4N40W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION ARE FROM THE EQUATOR TO 3N BETWEEN 36W-41W. CLUSTERS 
OF SCATTERED MODERATE CONVECTION ARE FROM 8N-12N BETWEEN 
44W-48W. 

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH IS MOVING ACROSS TEXAS INTO THE NW GULF AND 
ACROSS THE LOWER MISSISSIPPI VALLEY SUPPORTING A COLD FRONT AT 
17/2100 UTC OVER GEORGIA BECOMING STATIONARY OVER THE FLORIDA 
PANHANDLE JUST E OF TALLAHASSEE INTO THE GULF ALONG 28N89W 
27N95W THEN S TO INLAND OVER MEXICO JUST N OF TAMPICO WITH 
SCATTERED SHOWERS N OF THE FRONT TO INLAND OVER THE N GULF COAST 
E OF 90W WITH ISOLATED SHOWERS POSSIBLE N OF THE REMAINDER OF 
THE FRONT. NEAR ZONAL WESTERLY FLOW ALOFT WITH STRONG SUBSIDENCE 
AND DRY STABLE AIR ALOFT CONTINUES TO DOMINATE THE REMAINDER OF 
THE GULF LEAVING THE AREA SE OF THE FRONT WITH MOSTLY CLEAR 
SKIES AND FAIR WEATHER THIS EVENING. 

CARIBBEAN SEA...
STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT CONTINUES TO DOMINATE 
THE NW CARIBBEAN N OF 12N W OF 78W. AT 17/2100 UTC A SURFACE 
TROUGH EXTENDS FROM 20N82W S OF JAMAICA TO 16N75W WITH SCATTERED 
SHOWERS WITHIN 180/200 NM NE OF THE TROUGH AXIS. A BROAD UPPER 
RIDGE ANCHORED IN THE W TROPICAL ATLC DOMINATES THE S CARIBBEAN 
S OF A LINE FROM THE VIRGIN ISLANDS NEAR 18N63W TO NICARAGUA 
NEAR 14N84W. TROPICAL MOISTURE REMAINS OVER THE CENTRAL 
CARIBBEAN WITH POSSIBLE ISOLATED SHOWERS FROM 13N TO OVER 
HISPANIOLA BETWEEN 67W-74W. THE REMAINDER OF THE CARIBBEAN IS 
EXPERIENCING FAIR WEATHER THIS EVENING. 

ATLANTIC OCEAN...
THE SURFACE RIDGE COVERS THE W ATLC FROM 20N-32N W OF 50W TO 
JUST ACROSS THE FLORIDA PENINSULA ANCHORED BY A 1021 MB HIGH 
NEAR 27N66W WITH NEAR ZONAL WESTERLY FLOW ALOFT AS WELL AS 
STRONG SUBSIDENCE AND DRY STABLE AIR LIMITING ANY SHOWER 
ACTIVITY. AN UPPER TROUGH COVERS THE CENTRAL ATLC N OF 22N 
BETWEEN 30W-45W SUPPORTING A WEAKENING COLD FRONT THAT ENTERS 
THE CENTRAL ATLC NEAR 32N40W EXTENDING ALONG 27N42W TO 24N46W 
WHERE IT CONTINUES AS A SURFACE TROUGH TO 21N48W. SCATTERED 
SHOWERS ARE WITHIN 120 NM E OF THE FRONT N OF 25N. A WEAK 
SURFACE RIDGE REMAINS OVER THE E ATLC WITH A WEAK 1015 MB 
HIGH NEAR 22N41W. A SECOND UPPER LEVEL TROUGH IS OVER THE NE 
ATLC N OF 32N SUPPORTING A SECOND COLD FRONT ENTERING THE E ATLC 
NEAR 32N11W EXTENDING E OF THE CANARY ISLANDS ALONG THE COAST OF 
W AFRICA TO 24N16W THEN DISSIPATING TO 19N26W.  

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

$$
PAW