000 AXNT20 KNHC 250544 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI MAR 25 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 7N11W CROSS THE EQUATOR NEAR 21W CONTINUING SOUTH OF THE EQUATOR TO INLAND OVER E BRAZIL. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 3N TO S OF THE EQUATOR W OF 25W TO INLAND OVER SOUTH AMERICA. SMALL CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 90 NM OF 4N BETWEEN 8W-18W. ...DISCUSSION... GULF OF MEXICO... THE E GULF IS UNDER NEAR ZONAL WESTERLY FLOW ALOFT WHILE THE W GULF IS UNDER AN UPPER RIDGE ANCHORED OVER CENTRAL MEXICO WITH THE RIDGE AXIS EXTENDING ALONG THE TEXAS COAST TO OVER THE LOWER MISSISSIPPI VALLEY. STRONG SUBSIDENCE AND DRY STABLE AIR COVER THE GULF WATERS WHILE THE UPPER RIDGE OVER MEXICO IS DRAWING TROPICAL MOISTURE ALOFT ACROSS MEXICO AND S TEXAS. AS OF 25/0300 UTC A WEAK COLD FRONT EXTENDS FROM THE W ATLC ACROSS NE FLORIDA S OF JACKSONVILLE TO CEDAR KEY INTO THE GULF OF MEXICO TO 28N86W WHERE IT BECOMES NEAR STATIONARY TO 27N90W. THIS FRONT IS VOID OF ANY SHOWER ACTIVITY AND IS DELINEATED BY A SLIGHT WIND SHIFT. THE SURFACE RIDGE OVER THE W ATLC IS BEGINNING TO SHIFT W OVER THE SE GULF GIVING THE REMAINDER OF THE GULF S OF 27N MOSTLY FAIR WEATHER TONIGHT BUT REMNANT LOW LEVEL MOISTURE REMAINS AND COULD DEVELOP PATCHES OF ISOLATED SHOWERS. DEEP LOW PRESSURE OVER CENTRAL PLAIN STATES COMBINING WITH STRENGTHENING RIDGE ACROSS SE GULF COULD RESULT IN INCREASING S RETURN FLOW OVER GULF WATERS SAT AND SUN. CARIBBEAN SEA... BROAD UPPER RIDGE ANCHORED OVER THE TROPICS COVERS MOST OF THE CARIBBEAN GIVING THE AREA SW TO W FLOW ALOFT. STRONG SUBSIDENCE AND DRY STABLE AIR COVER ALL BUT THE EXTREME SE CARIBBEAN. FRESH TO MODERATE EASTERLY TRADE WINDS DOMINATE THE CARIBBEAN. THE EASTERLY TRADE WINDS COMBINED WITH THE WESTERLY FLOW ALOFT IS DEVELOPING PATCHES OF SCATTERED SHOWERS OVER THE CARIBBEAN MAINLY S OF 16N E OF 80W TO OVER THE WINDWARD ISLANDS. FRESH EASTERLY TRADES ARE EXPECTED TO WEAKEN LATER TODAY THROUGH SAT AS THE W ATLC RIDGE SHIFTS S. TRADE WINDS WILL BEGIN TO INCREASE ON SUN. ATLANTIC OCEAN... AN UPPER TROUGH IS OVER THE NW ATLC N OF 30N W OF 60W SUPPORTING A COLD FRONT THAT EXTENDS ALONG 32N TO A 1009 MB LOW NEAR 32N76W AND A WEAKER COLD FRONT EXTENDING FROM THE LOW SW ACROSS FLORIDA S OF JACKSONVILLE INTO THE GULF OF MEXICO. SCATTERED SHOWERS ARE WITHIN 90 NM SE OF THE FRONT E OF THE 1009 MB LOW. A WEAKENING 1017 MB LOW IS IN THE E ATLC NEAR 27N33W WITH A SURFACE TROUGH EXTENDING E TO 27N24W AND A SECOND SURFACE TROUGH EXTENDING S TO 21N35W. BROAD UPPER RIDGE ANCHORED IN THE TROPICS COVERS THE REMAINDER OF THE ATLC WATERS WITH A LARGE SURFACE RIDGE DOMINATING THE ATLC ANCHORED BY A 1023 MB HIGH NEAR 25N44W. THIS SURFACE RIDGE EXTENDS W TO THE SE GULF OF MEXICO S OF THE W ATLC FRONTAL BOUNDARY AND HAS A WEAKNESS IN THE E ATLC IN THE VICINITY OF THE LOW/SURFACE TROUGHS BUT IS GIVING THE ATLC MOSTLY FAIR WEATHER TONIGHT. W ATLC FRONT WILL SHIFT SE THROUGH SAT BEFORE DISSIPATING. SURFACE RIDGE WILL REMAIN THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW