000 AXNT20 KNHC 132342 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON FEB 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF SIERRA LEONE NEAR 8N13W TO 2N24W. THE ITCZ CONTINUES FROM 2N24W CROSSING THE EQUATOR AT 28W CONTINUING TO BRAZIL NEAR 3S44W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 3N-5N BETWEEN 14W-17W...AND FROM 3N-5N BETWEEN 43W-48W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING CONTINUES TO COVER THE ERN GULF OF MEXICO EXTENDING FROM A PAIR OF 1026 MB HIGHS OVER ALABAMA AND JUST OFFSHORE OF GEORGIA. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING FROM THE CARIBBEAN ACROSS THE GULF AND OVER THE SE CONUS. THIS PATTERN IS PROVIDING LIGHT E-SE FLOW AND FAIR CONDITIONS ACROSS THE ERN HALF OF THE BASIN WITH STRONGER AND MORE SLY FLOW UP TO 25 KTS OVER THE WRN HALF. AS OF 2100 UTC...A WEAK FRONTAL BOUNDARY HAS PUSHED OFF THE TEXAS COAST EXTENDING FROM 30N95W TO 26N98W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH OVER THE GREAT PLAINS REGION. SINCE THIS UPPER TROUGH IS WELL TO THE N OF THE BASIN THE FRONT WILL QUICKLY LOSE ITS UPPER LEVEL SUPPORT...AND IS EXPECTED TO STALL OUT AND LIFT N OF THE AREA ALLOWING RETURN FLOW TO RE-ESTABLISH OVER THE WRN GULF. SATELLITE AND RADAR IMAGERY INDICATE THAT SCATTERED SHOWERS ARE WITHIN 60 NM E OF THE FRONT WITH ISOLATED SHOWERS POSSIBLE W OF 89W TO THE FRONT. CARIBBEAN SEA... UPPER LEVEL RIDGING COVERS THE MAJORITY OF THE CARIBBEAN WITH AXIS EXTENDING FROM COLOMBIA TO THE GULF OF MEXICO AND ACROSS THE SE CONUS. WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR ALOFT WHICH IS HELPING MAINTAIN FAIR CONDITIONS ACROSS MUCH OF THE BASIN. HOWEVER...AN UPPER LEVEL TROUGH OVER THE W ATLC EXTENDING INTO THE FAR ERN CARIBBEAN SUPPORTS A FRONTAL BOUNDARY N OF THE BASIN WHICH TRANSITIONS INTO A SHEAR AXIS FROM HISPANIOLA NEAR 19N69W TO OFF THE COAST OF NICARAGUA ALONG 17N77W 14N82W. AN ASCAT PASS FROM EARLIER TODAY INDICATED SLIGHTLY STRONGER N-NE WINDS TO THE N OF THE AXIS WITH WEAKER NE WINDS TO THE S. CURRENTLY SCATTERED SHOWERS ARE ACROSS HISPANIOLA N OF 16N BETWEEN 67W-74W...AND FROM 15N-17N BETWEEN 78W-81W. THE REMAINDER OF THE BASIN HAS MOSTLY CLEAR SKIES WITH LIGHT TRADEWIND FLOW. EXPECT THE SHEAR AXIS TO GRADUALLY DISSIPATE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH COVERS THE W ATLC SUPPORTING A COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N51W CONTINUING SW TOWARD HISPANIOLA ALONG 25N59W 21N64W WHERE IT BECOMES STATIONARY TO THE ISLAND NEAR 19N69W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE AXIS. SURFACE RIDGING IS BEGINNING TO BUILD IN BEHIND THE FRONT ACROSS THE FAR WRN ATLC. STRATOCUMULUS CLOUDS COVER THIS AREA BEHIND THE FRONT TO THE ERN CONUS. ACROSS THE CENTRAL ATLC...A NARROW UPPER LEVEL RIDGE EXTENDS ALONG 22N50W TO 44N39W SUPPORTING A WEAK 1022 MB SURFACE HIGH NEAR 28N39W. A SHARP UPPER TROUGH IS IMMEDIATELY TO THE E ALONG 29W FROM 39N-21N WHERE IT TURNS SW TO 17N41W. THE UPPER TROUGH IS SUPPORTING A WEAKENING SURFACE LOW N OF THE DISCUSSION AREA. A SURFACE TROUGH ASSOCIATED WITH THE LOW SKIMS THE NRN BOUNDARY OF THE AREA ALONG 32N28W 30N33W 32N39W. A WEAK 1019 MB LOW IS ALSO ANALYZED ALONG THE TROUGH AXIS NEAR 30N31W. ISOLATED SHOWERS ARE N OF 28N BETWEEN 27W-31W. THE UPPER TROUGH IS ALSO SUPPORTING UPPER LEVEL CLOUDS RANGING FROM THE ITCZ REGION TO W AFRICA...AS WELL AS SOME SHOWERS NEAR THE ITCZ. BROAD UPPER RIDGING COVERS THE FAR ERN ATLC CENTERED NEAR 3N9W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON