000 AXNT20 KNHC 220554 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE FEB 22 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 07N11W TO 03N20W CROSSING THE EQUATOR NEAR 33W AND INTO NE BRAZIL NEAR 02S45W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 03N-07N BETWEEN 10W-19W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE RESIDES ALOFT OVER THE ENTIRE GULF WITH AXIS ALONG 88W. MOSTLY DRY AIR AND STRONG SUBSIDENCE IS NOTED ON WATER VAPOR IMAGERY WHICH IS ANTICIPATED TO CONTINUE PROVIDING MOSTLY CLEAR SKIES THROUGH THE OVERNIGHT PERIOD. AT THE SURFACE...A 1021 MB HIGH IS CENTERED IN THE W ATLC NEAR 26N65W THAT EXTENDS A RIDGE AXIS WESTWARD ALONG 26N TO 95W. SHIP AND BUOY OBSERVATIONS INDICATE S-SE WINDS IN THE RANGE OF 10 TO 15 KT ARE LOCATED ON THE WESTERN PERIPHERY OF THE RIDGE. WINDS ARE EXPECTED TO REMAIN SOUTHEASTERLY OVER THE NEXT 24 HOURS AS THE NEXT WEAK FRONTAL BOUNDARY SKIRTS THE NORTHERN GULF WATERS AND GULF COASTAL PLAIN LATE TUESDAY INTO WEDNESDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES VERY DRY AIR ALOFT OVER THE CARIBBEAN SEA BASIN WITH WEAK UPPER LEVEL TROUGHING EXTENDING FROM THE CENTRAL ATLC TO THE FAR NORTHERN LEEWARD ISLANDS. AT THE SURFACE...A 1021 MB HIGH IS CENTERED OVER THE W ATLC NEAR 26N65W THAT CONTINUES TO IMPACT MUCH OF THE BASIN WITH A STRONG PRESSURE GRADIENT RESULTING IN STRONG NE TO E WINDS ON THE SOUTHERN PERIPHERY OF THE RIDGE. THIS OVERALL SYNOPTIC PATTERN IS EXPECTED TO REMAIN IN PLACE THROUGH THE REMAINDER OF THE WEEK. ALSO OF NOTE...LOW-LEVEL MOISTURE ASSOCIATED WITH A DISSIPATED FRONTAL BOUNDARY NE OF THE LEEWARD ISLANDS IS ADVECTING ISOLATED SHOWERS OVER MUCH OF THE NE CARIBBEAN N OF 13N E OF 74W...INCLUDING PUERTO RICO AND THE US/UK VIRGIN ISLANDS. ATLANTIC OCEAN... UPPER LEVEL RIDGING LOCATED S OF 35N OVER MUCH OF THE EASTERN CONUS AND W ATLC W OF 60W CONTINUES TO SUPPORT AN EXPANSIVE 1021 MB HIGH CENTERED IN THE W ATLC NEAR 26N65W. INFLUENCE OF THE SURFACE RIDGE REMAINS MAINLY W OF 50W PROVIDING MOSTLY CLEAR SKIES AND FAIR CONDITIONS FOR THE BAHAMAS AND THE FLORIDA PENINSULA. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM 32N44W TO THE NE CARIBBEAN SEA NEAR 18N64W. THE UPPER LEVEL TROUGH SUPPORTS A COLD FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N37W THEN SW ALONG 23N45W TO 20N51W WHERE THE FRONT BECOMES MORE DIFFUSE AND BEGINS DISSIPATING WESTWARD TO 18N60W. SCATTERED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT N OF 24N WHILE ISOLATED SHOWERS LINGER WITHIN 60 NM EITHER SIDE OF THE FRONT S OF 24N. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 24N40W TO 17N48W WITH ISOLATED SHOWERS OCCURRING OVER THE AREA FROM 17N-24N BETWEEN 36W-48W. SOUTH OF THE AFOREMENTIONED FRONTAL BOUNDARY...A SURFACE TROUGH IS ANALYZED SE OF THE LESSER ANTILLES FROM SOUTHERN SURINAME NEAR 02N57W TO 12N53W. ISOLATED SHOWERS COVER A LARGE AREA WITHIN 400 NM EITHER SIDE OF THE TROUGH AXIS OVER THE OPEN ATLC WATERS WITH SCATTERED SHOWERS AND TSTMS OCCURRING OVER INLAND PORTIONS OF SOUTHEASTERN GUYANA AND WESTERN SURINAME. ELSEWHERE E OF 35W...A SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED NEAR 39N15W CONTINUES TO PROVIDE MOSTLY FAIR AND STABLE CONDITIONS ACROSS THE EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN