000 AXNT20 KNHC 221252 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAR 22 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH XXXX UTC. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST OF LIBERIA NEAR 6N10W CONTINUING SW ALONG 3N20W 1S30W INTO SOUTH AMERICA ALONG 4N39W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6S TO 3N BETWEEN 14W AND 31W. ISOLATED MODERATE TO STRONG CONVECTION IS WITHIN 170 NM S OF THE AXIS E OF 12W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE COVERS THE GULF OF MEXICO THIS MORNING... SUPPORTING A 1022 MB HIGH OFF THE COAST OF TAMPA FLORIDA NEAR 28N83W. THIS FEATURE ALONG WITH VERY DRY AIR AND STRONG SUBSIDENCE ALOFT IS PROVIDING FAIR WEATHER CONDITIONS ACROSS THE AREA. WINDS ARE LIGHT AND VARIABLE AROUND THE HIGH PRESSURE CENTER...WITH MODERATE TO FRESH EASTERLY WINDS W OF 86W S OF 28N AND SOUTHEASTERLY RETURN FLOW N OF 24N W OF 90W. THE SURFACE RIDGE IS EXPECTED TO REMAIN IN THE FAR EAST GULF MAINTAINING FAIR CONDITIONS ACROSS THE BASIN FOR THE NEXT 24 TO 36 HOURS. CARIBBEAN SEA... THE CARIBBEAN IS UNDER THE INFLUENCE OF A BROAD UPPER LEVEL RIDGE WITH ASSOCIATED DRY AIR AND STRONG SUBSIDENCE ACROSS THE MAJORITY OF THE BASIN. THIS SCENARIO IS LIMITING DEEP CONVECTION ACROSS THE AREA...LEAVING JUST A FEW AREAS OF WEAK SHOWERS SCATTERED ACROSS THE REGION...MOST NOTICED ACROSS THE CENTRAL AND FAR SE BASIN. THESE AREAS OF SHOWERS ARE MOVING WITH THE NE FRESH TO STRONG TRADE WIND FLOW. THIS FLOW ALSO GAINS A CYCLONIC TENDENCY AROUND THE COAST OF COLOMBIA WITH WINDS REACHING UP TO 25 KT. THIS IS GENERATING SOME OROGRAPHIC SHOWER ACTIVITY ALONG THE COAST OF COLOMBIA S OF 11N BETWEEN 72W-77W. COMPUTER MODELS SUGGEST SOME WEAK CONVECTION DEVELOPING OVER THE FAR SE BASIN IN WITHIN THE NEXT 24 HOURS...WITH NO OTHER SIGNIFICANT CHANGES EXPECTED DURING THE FORECAST PERIOD. ATLANTIC OCEAN... THE MAIN FEATURE OF INTEREST IN THE ATLC IS A COLD FRONT THAT EXTENDS FROM 32N38W SOUTHWESTWARD TO 22N45W AND WESTWARD TO 20N60W. FROM THAT POINT THE BOUNDARY CONTINUES AS A DISSIPATING COLD FRONT TO NEAR 21N71W NEAR THE TURKS AND CAICOS. A PRE FRONTAL TROUGH ENTERS THE REGION NEAR 31N36W AND CONTINUES SSW ALONG 24N37W TO 17N42W. THIS SYSTEM IS SUPPORTED ALOFT BY A DEEP LAYER TROUGH/LOW MOVING ACROSS THE N CENTRAL ATLC. SCATTERED SHOWERS ARE FOUND ALONG THE FRONTAL BOUNDARY WITH ISOLATED SHOWERS UP TO 40 NM BEHIND THE COLD FRONT. STRONGER AND HEAVIER SHOWERS ALONG WITH ISOLATED THUNDERSTORMS ARE WITHIN 170 NM EAST OF THE PRE FRONTAL TROUGH SEEN IN THE GEOSTATIONARY SATELLITE IMAGERY. EARLIER ASCAT SCATTEROMETER PASSES INDICATED NORTHERLY GUSTY WINDS UP TO 30 KT BEHIND THE COLD FRONT. WINDS EAST OF THE TROUGH ARE ENHANCED WITH 20 TO 30 KT SE WINDS. THE FAR W ATLC W OF 60W IS EXPERIENCING FAIR WEATHER CONDITIONS DUE TO AN UPPER LEVEL RIDGE SUPPORTING A 1022 MB NEAR 29N73W. THE REMAINDER OF THE E ATLC IS DOMINATED BY A WEAK 1016 MB HIGH NEAR 28N26W SUPPORTING FAIR WEATHER ACROSS THE AREA E OF 33W. COMPUTER MODELS SUGGEST THE FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVIE SOUTHEASTWARD WITH THE PRE-FRONTAL TROUGH RETAINING ITS IDENTITY AHEAD OF THE FRONT. AS THE COLD FRONT WEAKENS...A FEW SHOWERS MAY LINGER NEAR THE BOUNDARY DURING THE NEXT 24 TO 36 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FG/PAW