000
AXNT20 KNHC 231121
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI DEC 23 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE ITCZ EXTENDS FROM 7N12W TO 5N23W TO 6N40W TO 3N50W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 
8W-14W...FROM 3N-7N BETWEEN 15W-34W.  
 
...DISCUSSION...

GULF OF MEXICO...
AS OF 0900 UTC...A QUASI-STATIONARY FRONT EXTENDS FROM THE 
FLORIDA PANHANDLE TO NEAR VERACRUZ MEXICO ALONG 31N85W 24N93W 
19N95W. BROKEN TO OVERCAST LOW CLOUDS ARE WITHIN 90 NM OF THE 
FRONT. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT N OF 24N. 
10-15 KT N WINDS ARE N OF THE FRONT. 10-15 KT SOUTHERLY WINDS 
ARE E OF THE FRONT WITH MOSTLY FAIR WEATHER. THE FRONT HAS LOST 
UPPER AIR SUPPORT AGAIN AND STRONG UPPER LEVEL SUBSIDENCE 
PRESENTLY COVERS THE GULF OF MEXICO. EXPECT LITTLE CHANGE WITH 
THE FRONT POSITION OVER THE NEXT 24 HOURS. ALSO EXPECT THE FRONT 
TO BE BECOME MOSTLY VOID OF PRECIPITATION... WHILE AN UNRELATED 
AREA OF TROPICAL MOISTURE ADVECTS FROM THE YUCATAN PENINSULA TO 
THE BAY OF CAMPECHE WITH CONVECTION.   
  
CARIBBEAN SEA...
A TIGHT SURFACE PRESSURE GRADIENT IS OVER THE CARIBBEAN SEA. A 
GALE IS OFF THE COAST OF N COLOMBIA FROM 11N-15N BETWEEN 
73W-78W. 15-30 KT TRADEWINDS ARE OVER THE REMAINDER OF THE 
CARIBBEAN SEA. A MONSOON TROUGH EXTENDS FROM N COLOMBIA TO COSTA 
RICA. ISOLATED MODERATE CONVECTION IS ALONG THE NW COAST OF 
PANAMA. SCATTERED MODERATE CONVECTION IS OVER N NICARAGUA AND 
E HONDURAS FROM 12N-16N BETWEEN 82W-87W. MORE SCATTERED SHOWERS 
ARE ALONG THE COAST OF THE YUCATAN PENINSULA FROM 17N-22N 
BETWEEN 86W-89W. PATCHES OF BROKEN TO OVERCAST LOW CLOUDS WITH 
ISOLATED SHOWERS DOTS THE E CARIBBEAN E OF 72W. EXPECT OVER THE 
NEXT 24 HOURS FOR MORE SHOWERS TO ADVECT TO THE SW CARIBBEAN AND 
CENTRAL AMERICA. ALSO EXPECT THE GALE TO PERSIST FOR THE NEXT 18 
HOURS. 

ATLANTIC OCEAN...
A 1029 MB HIGH IS CENTERED OVER THE W ATLANTIC NEAR 32N58W. A 
SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC FROM 30N38W TO 
21N41W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 22N-28N 
BETWEEN 36W-43W. A 1035 MB HIGH IS CENTERED W OF SPAIN AT 
37N19W. A RIDGE AXIS EXTENDS S FROM THE HIGH TO 25N20W. EXPECT 
THE TROUGH TO REMAIN QUASI-STATIONARY OVER THE NEXT 24 HOURS 
WITH CONVECTION.

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

$$
FORMOSA