000
AXNT20 KNHC 252349
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST FRI FEB 25 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
2345 UTC.

...ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE COAST OF LIBERIA NEAR 6N10W 
CONTINUING SW ALONG 4N20W 2N30W INTO NE BRAZIL NEAR 4S38W.  
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM THE 
EQUATOR TO 5N E OF 27W. SIMILAR CONVECTION IS S OF 2N BETWEEN 
32W-44W. 

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LONGWAVE/TROUGH 
EXTENDING ACROSS THE EASTERN AND SE CONUS INTO THE NORTHERN GULF 
THIS AFTERNOON. THIS FEATURE SUPPORTS A COLD FRONT THAT ENTERS 
THE DISCUSSION AREA THROUGH NORTHERN FLORIDA NEAR 30N83W 
EXTENDING SW TO 26N90W...WHERE IT DISSIPATES TO NEAR 23N94W. A 
WEAK SURFACE TROUGH CONTINUES S INTO THE FAR SW BASIN TO NEAR 
VERACRUZ MEXICO WITH NO SIGNIFICANT CONVECTION. DOPPLER RADAR 
IMAGERY INDICATES SCATTER WEAK SHOWERS WITHIN 25 NM AHEAD OF THE 
COLD FRONT N OF 26N. MARINE OBSERVATIONS BEHIND THE FRONT SHOW 
NW WINDS 5-15 KT...BECOMING LIGHT W OF 91W WITH A FEW AREAS OF 
PATCHY FOG. SSW WINDS 5-10 KT ARE ELSEWHERE AHEAD OF THE FRONT. 
SHORT RANGE COMPUTER MODELS SUGGEST THE COLD FRONT WILL CONTINUE 
TO SLOWLY MOVE EAST BECOMING NEARLY STATIONARY OVER THE NEXT 24 
HOURS...WITH A FEW ISOLATED SHOWERS REMAINING ALONG THE 
BOUNDARY. AT THAT POINT...SSE SURFACE FLOW WILL BECOME DOMINANT 
ACROSS THE BASIN.   

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS A VERY DRY AND STABLE AIRMASS ALOFT 
ACROSS THE CARIBBEAN THIS AFTERNOON. AT SURFACE...TRADE WINDS 
10-20 KT ARE OBSERVED E OF 77W...WITH THE STRONGEST WINDS ALONG 
THE COAST OF COLOMBIA. THIS FLOW DIVERGES W OF 77W. THE OVERALL 
PATTERN IS ADVECTING A WARM AND MOIST AIRMASS FROM THE WESTERN 
TROPICAL ATLC BASIN INTO THE SOUTHERN CARIBBEAN S OF 15N. THIS 
AIRMASS IS GENERATING SCATTERED WEAK SHOWERS IN THIS REGION E OF 
75W...AND ALSO BANKING UP ALONG THE COAST OF PANAMA...COSTA 
RICA...NICARAGUA...AND HONDURAS BETWEEN 80W-85W S OF 16N. 
OTHERWISE...CONDITIONS ARE EXPECTED TO REMAIN CONSTANT OVER THE 
NEXT 24 HOURS. 

ATLANTIC OCEAN...
AN UPPER LEVEL LONGWAVE/TROUGH MOVES OFF THE EASTERN AND SE 
CONUS SUPPORTING A COLD FRONT NW OF THE AREA. HOWEVER...THE 
SOUTHERN EXTENSION OF THE FRONT IS EXPECTED TO ENTER THE WEST 
ATLC LATER THIS AFTERNOON WITH SCATTER WEAK CONVECTION. 
OTHERWISE...THE WESTERN ATLC IS CURRENTLY DOMINATED BY AN UPPER 
LEVEL RIDGE ANCHORED BY A 1026 MB HIGH NEAR 30N62W...SUPPORTING 
FAIR WEATHER CONDITIONS W OF 50W. A NARROW UPPER LEVEL TROUGH 
EXTENDS ACROSS THE CENTRAL ATLC AND SUPPORTS A NEARLY STATIONARY 
FRONT THAT ENTERS THE REGION ALONG 32N38W EXTENDING SW TO 25N46W 
BECOMING A SURFACE TROUGH TO NEAR 19N52W. THIS SYSTEM IS 
GENERATING SCATTERED WEAK CONVECTION N OF 20N BETWEEN 39W-46W. 
THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY ANOTHER UPPER 
LEVEL RIDGE ANCHORED BY A 1031 MB HIGH E OF THE AZORES NEAR 
38N17W. AS THE WESTERN ATLC HIGH MOVES EASTWARD AND THE EASTERN 
ATLC HIGH STRENGTHENS...SHORT RANGE COMPUTER MODELS SUGGEST THE 
NARROW UPPER TROUGH WILL SPLIT AND THE SOUTHERN END OF IT WILL 
INDUCE CYCLOGENESIS NEAR 25N39W IN THE NEXT 12 TO 24 HOURS.

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

$$

GARCIA