000
AXNT20 KNHC 120537
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EDT FRI NOV 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0535 UTC. 

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 12N17W TO 8N21W. THE ITCZ AXIS EXTENDS FROM 8N21W  
ALONG 6N31W TO 4N40W. CLUSTERS OF SCATTERED MODERATE TO STRONG 
CONVECTION ARE FROM 3N-10N BETWEEN 17W-34W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE HAS BUILT IN BEHIND THE COLD FRONT ANCHORED BY A 
1025 MB HIGH OVER THE NORTHERN GULF WATERS...OFF THE COAST OF 
ALABAMA NEAR 29N88W. THE STRONG NORTHERLY SURFACE WINDS ARE 
BANKING LOW CLOUDS WITH POSSIBLE ISOLATED SHOWERS ALONG THE E 
SLOPES OF THE SIERRA MADRE MOUNTAINS OF MEXICO AND WITHIN 90/120 
NM ALONG THE COAST S OF TAMPICO AND W OF CIUDAD DEL CARMEN. COLD 
AIR STRATOCUMULUS CLOUDS COVER MOST OF THE GULF WITH THE 
EXCEPTION OF THE NE GULF WHERE CLEAR SKIES PREVAIL. SURFACE 
RIDGE WILL MOVE E ALONG THE N GULF COAST ALLOWING FOR SOUTHERLY 
RETURN FLOW TO BECOME ESTABLISHED OVER THE W GULF THROUGH TUE 
...AHEAD OF THE NEXT COLD FRONT FORECAST TO ENTER THE GULF TUE 
EVENING.

CARIBBEAN SEA...
AN UPPER TROUGH IS APPROACHING THE NW CARIBBEAN SUPPORTING A 
WEAK STATIONARY FRONT EXTENDING FROM CENTRAL CUBA TO BELIZE 
ALONG 22N80W TO 18N88W. AT THE SAME TIME...WATER VAPOR IMAGERY 
INDICATES DRY STABLE AIR AND STRONG SUBSIDENCE OVER THE NW 
CARIBBEAN...THUS NO SHOWER ACTIVITY IS ASSOCIATED WITH THE 
FRONT. A SURFACE TROUGH IS MOVING ACROSS THE CENTRAL CARIBBEAN 
ANALYZED FROM THE SRN COAST OF DOMINICAN REPUBLIC NEAR 18N70W TO 
INLAND OVER NRN COLOMBIA 10N73W. HOWEVER...AN UPPER RIDGE OVER 
THIS REGION IS SUPPRESSING DEEP CONVECTION AROUND THE SURFACE 
TROUGH. THE MONSOON TROUGH CROSSES CENTRAL AMERICA INTO NORTHERN 
COLOMBIA GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS 
S OF 16N W OF 75W. SIMILAR CONVECTION IS ENTERING THE FAR SE 
CARIBBEAN. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH 
FAIR CONDITIONS THIS EVENING.  

ATLANTIC OCEAN...
A BROAD UPPER TROUGH MOVES OFF THE ERN CONUS SEABOARD SUPPORTING 
A COLD FRONT THAT EXTENDS INTO THE W ATLC THROUGH 32N63W 
BECOMING STATIONARY ALONG 26N72W ACROSS THE CENTRAL BAHAMA 
ISLANDS NEAR 24N76W INTO THE NW CARIBBEAN NEAR 23N80W. WATER 
VAPOR IMAGERY INDICATES DRY STABLE AIR AND STRONG SUBSIDENCE W 
AND E OF THE FRONT LIMITING SHOWER ACTIVITY WITH A NARROW SWATH 
OF MOISTURE ALONG THE FRONT. A NARROW UPPER TROUGH IS IN THE 
CENTRAL ATLC GENERATING SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS FROM 24N-30N BETWEEN 48W-52W. AN UPPER TROUGH 
COVERS THE E ATLC WITH A COLD FRONT EXTENDING THROUGH 32N17W TO 
26N26W. AN AMPLIFIED UPPER RIDGE REMAINS IN THE TROPICS DRAWING 
TROPICAL MOISTURE N FROM THE ITCZ WITH ISOLATED SHOWERS FROM 
15N-24N BETWEEN 18W-30W. THE WRN ATLC COLD FRONT WILL CONTINUES 
TO TRACK EASTWARD BEFORE DISSIPATING OVER THE CENTRAL ATLC ON 
MON. SURFACE RIDGE WILL BUILD BEHIND FRONT THROUGH TUE. A SECOND 
COLD FRONT WILL ENTER NW ATLC EARLY WED.

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

$$

GARCIA