000 AXNT20 KNHC 230553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED FEB 23 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... THE ITCZ AXIS IS ANALYZED ALONG 05N08W 01N32W 02N37W CROSSING THE EQUATOR NEAR 40W AND INTO NE BRAZIL NEAR 03S44W. SCATTERED MODERATE TO STRONG CONVECTION IS S OF 07N E OF 04W. ISOLATED MODERATE CONVECTION IS FROM 01N-04N BETWEEN 21W-26W...AND FROM 01N-03N BETWEEN 37W-43W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING CONTINUES TO DOMINATE ALOFT OVER THE GULF THIS EVENING WITH AXIS ALONG 90W THAT REACHES FROM THE YUCATAN PENINSULA NORTHWARD BEYOND THE GREAT LAKES REGION. WATER VAPOR IMAGERY INDICATES VERY DRY AIR LOCATES OVER THE SOUTHEASTERN HALF OF THE BASIN THAT SUPPORTS A SURFACE RIDGE EXTENDING FROM THE SW NORTH ATLC NEAR 23N70W TO THE NE GULF AND FLORIDA PENINSULA. BRIDGING THE SURFACE RIDGE...A WEAK COLD FRONT EXTENDS FROM A 1014 MB LOW CENTERED OVER SOUTHERN SOUTH CAROLINA NEAR 33N80W TO THE FLORIDA PANHANDLE...THEN BECOMES STATIONARY ALONG THE GULF COAST TO GALVESTON BAY AND THEN INLAND OVER DEEP SOUTHERN TEXAS. MOST SHIP AND BUOY OBSERVATIONS INDICATE E TO SE WINDS IN THE RANGE OF 10 TO 15 KT ACROSS MUCH OF THE GULF W OF 87W WITH LOW-LEVEL MOISTURE AND STRATUS NOTED ON SHORTWAVE INFRARED SATELLITE IMAGERY. A FEW COASTAL STATIONS ARE ALSO REPORTING LIMITED VISIBILITIES IN FOG...WHICH APPEARS TO IMPACT THE MAINLY THE WESTERN GULF N OF 22N W OF 92W. THE FRONTAL BOUNDARY IS EXPECTED TO GRADUALLY WEAKEN OVER THE NEXT 24 HOURS AS SOUTHERLY FLOW BEGINS TO INCREASE AHEAD OF THE NEXT FRONTAL BOUNDARY FORECAST TO IMPACT THE NW GULF WATERS BY EARLY FRIDAY. CARIBBEAN SEA... A PAIR OF UPPER LEVEL ANTICYCLONES AND ASSOCIATED RIDGING CONTINUES TO DOMINATE OVER MUCH OF THE CARIBBEAN SEA BASIN THIS EVENING. ONE UPPER LEVEL RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS THE YUCATAN PENINSULA INTO THE GULF OF MEXICO AND IS PROVIDING THE NW CARIBBEAN WITH VERY DRY AIR AND SUBSIDENCE ALOFT. THE OTHER UPPER LEVEL RIDGE REMAINS S OF 17N E OF 80W AND ALSO EXHIBITS DRY AIR AND AN OVERALL SUBSIDENT ENVIRONMENT. AT THE SURFACE...HIGH PRESSURE CENTERED THE ATLC WITH AXIS ALONG 23N BETWEEN 40W-75W IS MAINTAINING EASTERLY TRADEWINDS IN THE RANGE OF 15 TO 25 KT ACROSS THE CARIBBEAN SEA WITH A GENERAL LACK OF ANY SIGNIFICANT CONVECTION DUE TO THE STRONG UPPER LEVEL SUBSIDENCE. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH IMPACTS THE ATLC W OF 45W AND SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N62W THAT EXTENDS WESTWARD TO THE SOUTH CAROLINA COAST NEAR 33N80W. SCATTERED SHOWERS AND ISOLATED TSTMS REMAIN N OF 32N E OF 56W...HOWEVER ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT AS IT CONTINUES TO MOVE S-SE INTO THE DISCUSSION WATERS. SW TO W WINDS TO GALE FORCE ARE OCCURRING WITH THIS FRONT AS IT PRESSES AGAINST A RIDGE OF HIGH PRESSURE WITH AXIS ALONG 23N BETWEEN 40W-75W. BY EARLY THURSDAY THE COLD FRONT WILL BE LOCATED OVER THE CENTRAL ATLC WITH HIGH PRESSURE BUILDING SOUTHWARD OUT OF QUEBEC AND THE NE U.S...SETTLING IN OVER THE W ATLC AND CENTERED IN THE VICINITY OF BERMUDA BY EARLY FRIDAY. FARTHER EAST...A DISSIPATING STATIONARY FRONT IS ANALYZED FROM 32N29W SW ALONG 23N35W TO 16N52W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH CENTERED OFF THE COAST OF PORTUGAL NEAR 39N14W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN