000 AXNT20 KNHC 261739 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN FEB 26 2012 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLANTIC NEAR 8N13W TO 5N17W WHERE THE ITCZ AXIS CONTINUES ALONG 2N24W 1N28W CROSSING THE EQUATOR NEAR 31W INTO SOUTH AMERICA. SCATTERED MODERATE CONVECTION IS S OF 5N W OF 27W TO S OF THE EQUATOR AND INLAND OVER PORTIONS OF SOUTH AMERICA. ISOLATED THUNDERSTORMS ARE FROM 6N TO S OF THE EQUATOR BETWEEN 6W-20W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT EXTENDS ACROSS THE GULF SUPPORTED BY A BROAD UPPER TROUGH OVER THE NORTH ATLC. THE FRONT EXTENDS THROUGH THE STRAITS OF FLORIDA NEAR 24N80W TO A NEWLY DEVELOPED 1015 MB LOW NEAR 22N93W CONTINUING S INTO MEXICO NEAR 18N93W. A SHORTWAVE UPPER TROUGH THAT EXTENDS FROM THE LOUISIANA/TEXAS BORDER TO 23N93W IS ENHANCING THE DEVELOPMENT OF THIS LOW. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF THE FRONT W OF 93W. ISOLATED SHOWERS ARE POSSIBLE ELSEWHERE SE OF THE FRONT. WATER VAPOR IMAGERY SHOWERS DRIER AIR ALOFT MOVING INTO THE NW GULF. HOWEVER...LOW LEVEL DENSE CLOUD DECK REMAINS W OF 93W FROM MEXICO TO THE N GULF COAST. A BROAD UPPER RIDGE OVER THE CARIBBEAN EXTENDS OVER THE SE GULF WHILE A BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS TO OVER THE FAR SW GULF. ALTHOUGH A FRONT/LOW IS FOUND IN THE GULF...THE OVERALL SURFACE PRESSURE REMAINS RATHER HIGH WITH A SURFACE RIDGE COVERING THE N GULF ANCHORED BY A 1033 MB HIGH OVER EASTERN NORTH CAROLINA. THE LOW WILL SLOWLY LIFT NW AND WEAKEN TO A TROUGH THROUGH TONIGHT WHILE THE FRONT BECOMES DIFFUSE AND DISSIPATES THROUGH MON NIGHT AS ATLC SURFACE RIDGE BUILDS WESTWARD ACROSS THE GULF. A WEAK COLD FRONT WILL MOVE FROM NE TEXAS TO E LOUISIANA LATE ON WED AND SHIFT NE OF THE AREA THU. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE CARIBBEAN WITH THE AXIS EXTENDING FROM COLOMBIA THROUGH THE WINDWARD PASSAGE INTO THE W ATLC. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATES THE ALL OF THE CARIBBEAN. A FAIRLY TIGHT PRESSURE GRADIENT IS BEING MAINTAINED BY THE RELATIVE HIGH PRESSURE OVER THE ATLC BASIN AND THE LOWER PRESSURE OVER SOUTH AMERICA TO GENERATE FRESH TO STRONG EASTERLY TRADE WINDS ACROSS THE CARIBBEAN BASIN. THESE TRADE WINDS ARE USHERING IN SOME LOW LEVEL FAST MOVING SHOWERS DOTTING THE AREA E OF A LINE FROM SW HAITI TO NE HONDURAS AND WITHIN 90 NM ALONG THE COAST OF THE YUCATAN AND BELIZE BUT OVERALL FAIR WEATHER ACROSS THE AREA. SURFACE RIDGE OVER THE W ATLC WILL BUILD EASTWARD WHILE STRENGTHENING THROUGH TUE NIGHT MAINTAINING THE TRADE WINDS ACROSS THE AREA. THE RIDGE WILL THEN WEAKEN AS IT SLIDES E ON WED AND THU ALLOWING FOR WINDS TO DIMINISH OVER MUCH OF THE BASIN. ATLANTIC OCEAN... A BROAD UPPER TROUGH IS OVER THE NORTH ATLC N OF 30N SUPPORTING A COLD FRONT THAT ENTERS INTO THE W/CENTRAL ATLC NEAR 32N61W EXTENDING ALONG 26N70W THE THE BAHAMA ISLANDS NEAR 24N76W WHERE IT BECOMES STATIONARY INTO THE GULF OF MEXICO THROUGH THE STRAITS OF FLORIDA NEAR 24N80W. SCATTERED SHOWERS ARE WITHIN 45 NM E OF THE FRONT WITH POSSIBLE ISOLATED SHOWERS WITHIN 90/120 NM NW OF THE FRONT. A SURFACE RIDGE IS BUILDING BEHIND THE FRONT OVER THE NW ATLC ANCHORED BY A 1033 MB HIGH OVER EASTERN NORTH CAROLINA. THE UPPER RIDGE OVER THE CARIBBEAN COVERS THE W ATLC WITH THE AXIS EXTENDING THROUGH THE WINDWARD PASSAGE ENE TO BEYOND 32N46W. A BROAD UPPER TROUGH COVERS THE REMAINDER OF THE ATLC WITH THE AXIS EXTENDING FROM AN UPPER LOW NEAR 25N28W THROUGH 32N30W TO A SECOND UPPER LOW NEAR 21N44W TO 14N56W. A STRONG UPPER HIGH IS IN THE E TROPICAL ATLC JUST OFF THE COAST OF AFRICA NEAR 8N17W COVERING THE AREA S OF 23N W OF THE ABOVE UPPER TROUGH. A SURFACE RIDGE DOMINATES THE ATLC E OF THE FRONT ANCHORED BY A SERIES OF HIGHS N OF THE DISCUSSION AREA AND A 1030 MB HIGH NEAR 32N40W. THE COLD FRONT WILL DISSIPATE W OF 75W THROUGH MON NIGHT AND DISSIPATE E OF 75W BY TUE. SURFACE RIDGE WILL BUILD ACROSS THE AREA IN THE WAKE OF THE FRONT THEN WEAKEN AND SHIFT E INTO THE CENTRAL ATLC WED ALLOWING FOR A WEAK COLD FRONT TO BRUSH THE FAR N WATERS THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW