000 AXNT20 KNHC 281752 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON MAR 28 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 07N12W 02N25W CROSSING THE EQUATOR NEAR 34W AND INTO NE BRAZIL NEAR 01S46W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 18W-29W. ...DISCUSSION... GULF OF MEXICO... A WEAK UPPER LEVEL SHORTWAVE TROUGH IS LOCATED OVER THE NW GULF WATERS AND SUPPORTS A 1010 MB SURFACE LOW CENTERED OVER THE WESTERN FLORIDA PANHANDLE AND ASSOCIATED COLD FRONT EXTENDING W-SW FROM THE LOW ALONG 29N90W TO THE TEXAS COAST NEAR 27N97W. WHILE A LACK OF ANY SIGNIFICANT CONVECTION IS LOCATED ALONG THE COLD FRONT...SURFACE OBSERVATIONS OVER TEXAS AND LOUISIANA INDICATE THAT A MARGINALLY COOLER AND RELATIVELY DRIER AIRMASS IS LOCATED NW OF THE FRONTAL BOUNDARY. MOST INSTABILITY AND LOW-LEVEL CONVERGENCE IS FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM APALACHICOLA FLORIDA NEAR 30N85W TO 27N91W. MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA INDICATE NUMEROUS SHOWERS AND SCATTERED TSTMS OCCURRING OVER THE AREA FROM 27N-31N EAST OF THE SURFACE TROUGH. A STATIONARY FRONT EXTENDS EASTWARD FROM THE LOW ALONG 30N FROM THE WESTERN FLORIDA PENINSULA ACROSS NORTHERN FLORIDA INTO THE SW NORTH ATLC WATERS. THIS FRONTAL SYSTEM IS EXPECTED TO SHIFT EAST OF THE GULF THROUGH TUESDAY WITH S-SE RETURN FLOW RE-ESTABLISHING ACROSS THE WESTERN GULF AHEAD OF THE NEXT FRONT EXPECTED TO ENTER THE NW GULF WATERS BY EARLY WEDNESDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES A BROAD UPPER LEVEL RIDGE EXTENDS FROM THE TROPICAL NORTH ATLC NEAR 06N52W NW OVER THE EASTERN CARIBBEAN AND HISPANIOLA TO 20N72W. EAST OF THE RIDGE AXIS...THE REMAINDER OF THE WESTERN CARIBBEAN IS UNDER THE INFLUENCE OF VERY WEAK BROAD-SCALE TROUGHING WHICH IS LARGELY ACCOMPANIED BY DRY AIR ALOFT. GIVEN THE OVERALL STABILITY OF THE ATMOSPHERE ALOFT...AT THE SURFACE...FRESH TO STRONG TRADEWINDS PERSIST WITH VERY FEW AREAS OF SHOWER ACTIVITY THIS AFTERNOON. HOWEVER...THE APPROACH OF A SWIFT MOVING SURFACE TROUGH FROM 10N-16N ALONG 57W EAST OF THE LESSER ANTILLES IS PROVIDING AREAS OF LOW-LEVEL CONVERGENCE WEST OF THE SURFACE TROUGH AXIS. ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH AXIS AS WELL AS OVER MANY OF THE LESSER ANTILLES ISLANDS N OF 13N AND N OF 16N BETWEEN 63W-66W...WHICH INCLUDES THE US/UK VIRGIN ISLANDS AND EASTERN PUERTO RICO. ATLANTIC OCEAN... A WESTERN NORTH ATLC DEEP LAYER TROUGH IS LOCATED WELL NORTH OF THE DISCUSSION AREA IN THE VICINITY OF THE CANADIAN MARITIMES AND EXTENDS A COLD FRONT FROM BERMUDA NEAR 32N65W TO 31N70W THEN BECOMES STATIONARY TO THE FLORIDA COAST NEAR 30N81W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING OVER THE SW NORTH ATLC WATERS N OF 26N W OF A LINE FROM 32N71W TO 26N79W. THIS FRONTAL BOUNDARY IS EXPECTED TO DRIFT VERY SLOWLY SOUTHEASTWARD OVER THE NEXT 24 HOURS LOCATING ALONG 28N/29N BETWEEN 65W-80W BY EARLY TUESDAY. ELSEWHERE...THE REMAINDER OF THE ATLC BASIN IN UNDER THE INFLUENCE OF AN EXPANSIVE AND BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NEAR 31N29W. MOSTLY FAIR WEATHER CONDITIONS ARE NOTED N OF 05N E OF 70W. HOWEVER...A PAIR OF SURFACE TROUGHS ARE EMBEDDED WITHIN THE SOUTHWEST PERIPHERY OF THE RIDGE. ONE SURFACE TROUGH IS LOCATED NORTH OF HISPANIOLA ANALYZED FROM 20N72W TO 26N67W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM E OF THE SURFACE TROUGH AXIS. THE OTHER SURFACE TROUGH IS LOCATED FROM 10N-16N ALONG 57W. ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH AXIS AND OVER AN AREA NE OF THE LEEWARD ISLANDS FROM 14N-19N BETWEEN 54W-65W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN