000
AXNT20 KNHC 242359
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST THU FEB 24 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 05N09W TO 02N30W TO 00N35W TO 
INLAND OVER SOUTH AMERICA AT 03S42W.  SCATTERED  MODERATE AND 
ISOLATED STRONG CONVECTION WITHIN 60 NM OF AXIS E OF 13W... 
WITHIN 45 NM OF AXIS 18W TO 25W AND FROM 36W TO INLAND OVER 
SOUTH AMERICA. 

...DISCUSSION...

GULF OF MEXICO...
ENTIRE GULF UNDER UPPER LEVEL RIDGE PRODUCING VERY DRY AIR UNDER 
MODERATE TO STRONG SUBSIDENCE.  SOUTHWEST NORTH ATLANTIC SURFACE 
RIDGE DRIFT FURTHER EAST ENHANCING SOUTHERLY RETURN FLOW ALONG 
COAST OF TEXAS.  EARLIER EXTENSIVE AREAS OF SEA FOG WITH 
VISIBILITIES BELOW 3 NM HAVE DIMINISHED IN AREA COVERAGE BUT 
STILL CAN BE NOTED NORTH OF 29N FROM 83W TO 86WOW WHILE MOSTLY 
LIFTED WEST OF 94W.  SCATTERED PATCHES OF RAIN STILL LINGER 
ALONG TEXAS NORTHEAST COAST.  SURFACE RIDGE WILL MOVE FURTHER 
EAST FORCED BY COLD FRONT APPROACHING TEXAS COAST WITH SCATTERED 
SHOWERS STARTING TONIGHT THROUGH FRI. 

CARIBBEAN SEA...
WEAK UPPER LEVEL TROUGH OVER WESTERN HALF OF BASIN BEING PUSHED 
BY BROAD RIDGE MOVING EAST FROM GULF OF MEXICO.  VERY DRY AIR 
MASS ACROSS BASIN W OF 65W WHILE MINOR AMOUNTS OF MOISTURE EAST 
OF 65W IS ABSORBED IN SUCH DRY ENVIRONMENT.  UPPER LEVEL 
DIFFLUENT FLOW OVER COLOMBIA MAINTAINS ASCENDING MOISTURE AND 
SUPPORTS SURFACE LOW PRESSURE JUST OFF PACIFIC COAST OF 
COLOMBIA.  SURFACE RIDGE OVER SW N ATLANTIC MAINTAINS CONSTANT 
EAST TO NORTHEAST BREEZE ACROSS ENTIRE BASIN.  ISOLATED TO 
SCATTERED QUICK MOVING LIGHT SHOWERS DOT THE LESSER ANTILLES.  

ATLANTIC OCEAN...
BROAD MID TO UPPER LEVEL RIDGE MOVES EAST FORCING LONGWAVE 
TROUGH INTO CENTRAL NORTH ATLANTIC.  LARGE SURFACE RIDGE 1025 MB 
JUST NORTH OF REGION MAINTAINS STEADY FLOW OF EAST TO NORTHEAST 
MODERATE TO FRESH BREEZE ACROSS LOWER LATITUDES EAST OF 75W 
WHILE MODERATE SOUTHEAST FLOW PREVAILS WEST OF 75W.  WEAKENING 
COLD FRONT FROM 31N40W TO 22N63W TO 23N66W SUPPORTED BY UPPER 
LEVEL LONGWAVE TROUGH PRODUCING BROAD AREAS OF SCATTERED 
CONVECTION E OF 55W BUT THINNER LINES ALONG ITS BOUNDARY FROM 
55W TO 64W.   

DOWNSTREAM RIDGE COMPLETES UPPER LEVEL PICTURE OVER EASTERN 
ATLANTIC TO AFRICAN COAST.  SURFACE HIGH PRESSURE 1029 MB OFF 
PORTUGAL COAST EXTEND TO JUST EAST OF COLD FRONT WITH WARM FRESH 
BREEZE OVER AZORES ISLANDS.  FRONT EXPECTED TO MOVE SOUTHEAST 
AND STALL AS UPPER LEVEL SUPPORT SHIFT NE.

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

$$
WALLY BARNES