000 AXNT20 KNHC 242352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 24 2010 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... ITCZ AXIS IS CENTERED ALONG 8N13W 3N20W 2N40W AND INTO NE BRAZIL NEAR THE EQUATOR AND 49W. SCATTERED MODERATE CONVECTION IS FROM 3N-6N BETWEEN 7W-13W. SIMILAR CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 25W-33W AND FROM 1N-5N BETWEEN 37W-46W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER LEVEL NEGATIVELY TILTED TROUGH ACROSS THE MID-MISSISSIPPI RIVER VALLEY THAT SUPPORTS A COLD FRONT ENTERING THE GULF OF MEXICO NEAR CAILLOU BAY LOUISIANA AND EXTENDS S-SW ALONG 25N93W TO 22N96W BECOMING STATIONARY TO MEXICO NEAR 21N97W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EAST OF THE FRONT. EAST OF THE FRONT ACROSS THE REMAINDER OF THE GULF...INCLUDING THE FLORIDA PENINSULA...MAINLY SOUTHERLY FLOW DOMINATES WITH FAIRLY MOIST AND HUMID CONDITIONS THIS EVENING AS DEWPOINTS ARE IN THE RANGE OF MID 60S TO LOWER 70S. WEST OF THE FRONT...A WEAK RIDGE IS IN PLACE ACROSS THE NW GULF...CENTERED NEAR BROWNSVILLE TEXAS. THIS RIDGE IS EXPECTED TO SUSTAIN WEAK ANTICYCLONIC FLOW OVER THE NW GULF UNTIL EARLY TUESDAY WHEN THE NEXT COLD FRONT IS FORECAST TO CLIP THE NW GULF WATERS. CARIBBEAN SEA... AN UPPER LEVEL RIDGE COVERS THE WESTERN CARIBBEAN W OF 68W WITH THE CENTER OF ANTICYCLONIC CIRCULATION OVER EASTERN HONDURAS NEAR 15N85W. THIS DOME OF HIGH PRESSURE ALOFT IS SUPPORTING STABLE AND MODERATELY DRY AIR OVER THE WESTERN CARIBBEAN GIVING WAY TO GENERALLY CLEAR SKIES THIS EVENING. E TO SE SURFACE WINDS UP TO 20 KT WERE OBSERVED ON EARLIER WINDSAT AND ASCAT PASSES W OF 77W. THE REMAINDER OF THE CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM THE CENTRAL ATLC ALONG 20N62W TO NORTHERN VENEZUELA NEAR 11N67W. THIS UPPER LEVEL TROUGH SUPPORTS THE REMNANTS OF AN OLD FRONTAL BOUNDARY...NOW ANALYZED AS A SHEAR LINE THROUGH THE ANEGADA PASSAGE TO SE PUERTO RICO NEAR 18N66W TO 17N70W. ISOLATED SHOWERS ARE REMAINING N OF 16N AND E OF 70W...INCLUDING PORTIONS OF HISPANIOLA. GLOBAL COMPUTER MODELS INDICATE THE ACTIVITY IN THIS REGION MAY LINGER THROUGH EARLY SUNDAY UNTIL SURFACE HIGH PRESSURE TAKES HOLD OVER A MAJORITY OF THE SW NORTH ATLC. ATLANTIC OCEAN... A SURFACE RIDGE COVERS THE WESTERN ATLC ANCHORED BY A 1020 MB HIGH CENTERED NE OF THE BAHAMAS NEAR 28N72W. THIS FEATURE IS RESULTING IN GENERALLY FAIR WEATHER N OF 20N W OF 62W. HOWEVER...A FEW ISOLATED SHOWERS ARE ALONG THE GEORGIA AND SOUTH CAROLINA COAST N OF 31N IN ASSOCIATION WITH A STATIONARY FRONTAL BOUNDARY NORTH OF THE DISCUSSION AREA. FARTHER EAST...AN UPPER LEVEL LOW WELL NORTH OF THE REGION ACROSS THE CENTRAL ATLC IS RESPONSIBLE FOR A SET OF FRONTAL BOUNDARIES THAT EXTEND S OF 32N. THE EASTERNMOST FRONT ENTERS AS A DISSIPATING STATIONARY BOUNDARY NEAR 31N38W AND EXTENDS SW ALONG 25N44W TO 20N57W THEN CONTINUES AS A SHEAR LINE INTO THE NE CARIBBEAN SEA THROUGH THE ANEGADA PASSAGE. SCATTERED SHOWERS ARE WITHIN 240 NM EAST OF THE FRONT N OF 24N WHILE ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE BOUNDARY S OF 24N. THE SECOND FRONT...A COLD FRONT EXTENDS FROM 31N45W TO 23N58W WITH A DEFINED LOW-LEVEL CLOUD LINE EVIDENT ON THE LAST FEW VISIBLE SATELLITE IMAGES OF THE DAY. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. THIS FRONT IS EXPECTED TO BE REINFORCED FROM THE NW AS ANOTHER BOUNDARY EXTENDS FROM 32N51W TO 29N60W AND IS LARGELY SUPPORTED BY THE UPPER LEVEL TROUGHING ACROSS THE CENTRAL ATLC. AN ENHANCED WIND FIELD FOLLOWS IN THE WAKE OF THIS THIRD FRONT WITH WINDS TO GALE FORCE N OF 29N W OF THE FRONT TO 62W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF AN SURFACE RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 25N25W. HOWEVER...EMBEDDED WITHIN THE SURFACE RIDGE A WEAK AREA OF LOWER PRESSURE IS CENTERED NEAR 31N23W THAT EXTENDS A WEAKENING COLD FRONT ALONG 31N22W 28N24W TO 26N28W. ISOLATED SHOWERS ARE WITHIN 45 NM EITHER SIDE OF THE FRONTAL BOUNDARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN