000 AXNT20 KNHC 090548 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST FRI MAR 09 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE NRN COAST OF SIERRA LEONE AT 9N13W TO 3N17W. THE ITCZ CONTINUES FROM 3N17W CROSSING THE EQUATOR AT 28N TO 2S32W RECROSSING THE EQUATOR AT 37W TO 1N40W TO THE NRN COAST OF BRAZIL AT EQ48W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE AXIS BETWEEN 14W-20W ...DISCUSSION... GULF OF MEXICO... THE GULF OF MEXICO CONTINUES TO LIE UNDERNEATH AN UPPER LEVEL RIDGE EXTENDING FROM THE E PACIFIC ACROSS THE BAY OF CAMPECHE CONTINUING TOWARD THE NE TO THE W ATLC. THE UPPER RIDGE SUPPORTS A SURFACE RIDGE COVERING THE W ATLC WITH AXIS EXTENDING INTO THE GULF FROM NRN FLORIDA TO THE SW GULF. THIS PATTERN IS PROVIDING SE-S SURFACE FLOW ACROSS THE BASIN WITH SPEEDS RANGING FROM 10-20 KTS. DRY AIR ALOFT IS HELPING MAINTAIN FAIR CONDITIONS WITH MOSTLY CLEAR SKIES BESIDES A FEW ISOLATED SHOWERS ACROSS FLORIDA. HOWEVER...AN UPPER LEVEL TROUGH MOVING ACROSS THE GREAT LAKES REGION TO THE SW CONUS SUPPORTS A COLD FRONT STILL N OF THE AREA WHICH IS PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS ACROSS THE SE CONUS INCLUDING SEVERAL OF THE GULF COAST STATES. THIS FRONT IS EXPECTED TO MOVE INTO THE NW GULF WITHIN THE NEXT 12 HOURS WHERE IT WILL QUICKLY STALL AND RETREAT BACK TOWARDS TEXAS. SHOWERS AND THUNDERSTORMS WILL LIKELY MOVE ACROSS THE NW GULF WATERS SHORTLY AS THE FRONT APPROACHES THE AREA. CARIBBEAN SEA... FAIR CONDITIONS REMAIN ACROSS THE CARIBBEAN TONIGHT DUE TO DRY AIR AND SUBSIDENCE ALOFT AROUND AN UPPER LEVEL TROUGH EXTENDING FROM HAITI TO PANAMA. UPPER LEVEL RIDGES ARE TO EITHER SIDE OF THE TROUGH ALSO ACCOMPANIED BY DRY AIR. AT THE SURFACE...TRADEWIND FLOW OF 20-25 KTS IS ACROSS MUCH OF THE BASIN REACHING GALE FORCE NEAR THE COAST OF COLOMBIA. SOME SCATTERED SHOWERS HAVE MOVED ACROSS THE SRN WINDWARD ISLANDS AND NRN VENEZUELA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE EXTENDS FROM THE GULF OF MEXICO AND JUST OFFSHORE THE ERN SEABOARD SUPPORTING A STRONG SURFACE RIDGE ACROSS THE W ATLC ANCHORED BY A 1038 MB HIGH NEAR 37N54W. MOSTLY FAIR WEATHER IS ACROSS THIS PORTION OF THE BASIN BESIDES AN AREA SHOWERS/THUNDERSTORMS FROM 21N-28N BETWEEN 57W-64W. THIS ACTIVITY IS ENHANCED BY AN UPPER LEVEL TROUGH EXTENDING FROM 37N56W TO HISPANIOLA. SOME OF THE ACTIVITY IS ALSO INFLUENCED BY A SHEAR AXIS EXTENDING FROM A COLD FRONT N OF THE DISCUSSION AREA ALONG 31N34W 26N43W 23N59W. THE FRONT N OF THE AREA IS SUPPORTED BY AN UPPER LEVEL TROUGH ALONG 37W TO THE N OF 26N. A SURFACE TROUGH IS E OF THE SHEAR AXIS ALONG 29N33W TO 22N38W. UPPER LEVEL RIDGING COVERS THE FAR ERN ATLC WITH AXIS ALONG 23W. UPPER LEVEL RIDGING ALSO COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON