000
AXNT20 KNHC 012352
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT TUE NOV 01 2011 

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 2315 UTC.

...TROPICAL WAVES...
AN ATLANTIC TROPICAL WAVE EXTENDS FROM 12N36W TO 4N45W MOVING W 
NEAR 15 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF ENHANCED 
MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-13N BETWEEN 
34W-43W. SIMILAR ACTIVITY IS FROM 7N-10N BETWEEN 44W-48W. 
ISOLATED MODERATE/STRONG CONVECTION IS FROM 3N-5N BETWEEN 
39W-43W.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXITS THE SENEGAL COASTLINE NEAR 14N17W AND 
EXTENDS TO 12N19W. SCATTERED SHOWERS ARE MOSTLY S AND ALONG THE 
TROUGH AXIS WITHIN 65 NM. THE ITCZ CONTINUES FROM 5N19W TO 5N27W 
TO 7N35W. SCATTERED MODERATE TO STRONG CONVECTION ARE N OF THE 
ITCZ AXIS FROM 5N-10N BETWEEN 20W-30W. IN THE WESTERN SIDE OF 
THE ITCZ FROM 6N-10N BETWEEN 32W-35W THERE IS MODERATE TO STRONG 
CONVECTION ASSOCIATED TO THE TROPICAL WAVE AHEAD OF IT.  

...DISCUSSION...

THE GULF OF MEXICO...

SURFACE RIDGING DOMINATES N OF 25N ASSOCIATED TO A 1027 MB 
SURFACE HIGH CENTERED IN WEST VIRGINIA NEAR 38N80W. WINDS 
MAGNITUDE RANGE FROM 15-20 KT AROUND THE RIDGE. BELOW 25N CYCLONIC 
FLOW OF THE SAME MAGNITUDE PREVAILS WHICH IS ENHANCING SHOWER 
ACTIVITY IN THE YUCATAN PENINSULA. IN THE UPPER LEVELS WATER 
VAPOR IMAGERY SHOW STRONG DRY AIR SUBSIDENCE AROUND AN UPPER 
RIDGE CENTERED OVER THE YUCATAN PENINSULA WHICH IS PROVIDING 
FAIR WEATHER TO THE ENTIRE GULF. AN UPPER LEVEL TROUGH...ALSO 
ACCOMPANIED BY DRY AIR IS ACROSS THE FLORIDA PENINSULA.

THE CARIBBEAN SEA...

IN THE WESTERN CARIBBEAN A STATIONARY FRONT CROSSES WESTERN CUBA 
AND THEN EXTENDS OVER WATER FROM 22N82W TO 20N86W. A SURFACE 
TROUGH CONTINUES FROM THE END OF THE FRONT SOUTHWARD TO 12N82W. 
THIS FRONTAL AND TROUGH SYSTEM IS BEING SUPPORTED BY AN UPPER 
LEVEL TROUGH THAT EXTENDS ALONG THE FLORIDA PENINSULA TO THE 
YUCATAN PENINSULA. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 60 NM EITHER SIDE OF THE FRONT AND TROUGH. IN THE 
SOUTHWESTERN CARIBBEAN SHOWERS AND THUNDERSTORM ACTIVITY ARE 
ASSOCIATED TO THE MONSOON TROUGH. THIS CONVECTIVE ACTIVITY CAN 
BE OBSERVED AS SCATTERED MODERATE CONVECTION OVER COSTA RICA AND 
PANAMA AND WITHIN 170 NM ALONG THE COASTLINE OF COLOMBIA. 
SHOWERS AND THUNDERSTORM ACTIVITY OVER THE GREATER ANTILLES AND 
SOUTH OF PUERTO RICO ARE ASSOCIATED TO AN UPPER LEVEL LOW 
CENTERED NEAR 13N75W AND DIFLUENT FLOW EXTENDING TO THE NE UP TO 
20N.   

THE ATLANTIC OCEAN...

IN THE WESTERN ATLANTIC A STATIONARY FRONT EXTENDS FROM 30N69W 
SOUTHWESTWARD ACROSS THE WRN BAHAMAS TO 23N80W. SCATTERED 
SHOWERS ARE 70 NM EITHER SIDE ALONG THE FRONT. THIS FRONTAL 
SYSTEM IS BEING SUPPORTED BY AN UPPER LEVEL TROUGH WITH AXIS 
CENTERED ALONG THE E COAST OF FLORIDA. A SURFACE TROUGH EXTENDS 
N OF THE CARIBBEAN FROM 26N61W SOUTHWARD TO 19N65W.  
THUNDERSTORM ACTIVITY IS LOCATED WITHIN 120 NM W OF THE TROUGH 
AXIS N OF 24N. THE CENTRAL AND EASTERN ATLANTIC IS DOMINATED BY 
WEAK SURFACE RIDGING DUE TO A STRONG UPPER LEVEL RIDGE CENTERED 
NEAR 28N40W. EXCEPT FOR THE MONSOON TROUGH AND THE ITCZ REGIONS 
DRY AIR SUBSIDENCE DOMINATES BRINGING FAIR WEATHER. 

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

$$
NR/CW