000 AXNT20 KNHC 120553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT MAY 12 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 AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W TO 7N17W WHERE THE ITCZ CONTINUES ALONG 5N21W ALONG 4N34W TO INLAND OVER SOUTH AMERICA NEAR 1N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE N OF 3N TO THE COAST OF LIBERIA BETWEEN 8W-11W AND FROM 6N-9N E OF 14W TO INLAND OVER SIERRA LEONE. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 90/120 NM N OF THE ITCZ BETWEEN 24W-42W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE IS THE DOMINATING THE GULF WITH THE AXIS EXTENDING FROM AN UPPER HIGH OFF THE COAST OF GUATEMALA IN THE E PACIFIC REGION OVER THE YUCATAN PENINSULA TO OVER APALACHICOLA BAY FLORIDA. AN UPPER LOW IS OVER S OKLAHOMA WITH AN UPPER TROUGH EXTENDING S TO OVER TEXAS EXTENDING E TO OVER THE LOWER MISSISSIPPI VALLEY. UPPER DIFFLUENCE BETWEEN THESE UPPER LEVEL FEATURES GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 25N TO INLAND OVER THE N GULF COAST BETWEEN 85W-94W. THE UPPER FLOW IS DRAWING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM OVER S MEXICO INTO THE BAY OF CAMPECHE TO 20N BETWEEN 93W-97W AND OVER NE MEXICO WITHIN 60 NM ALONG THE COAST BETWEEN 23N-25W WITH ISOLATED SHOWERS COVERING THE REMAINDER OF THE W GULF. SHOWERS/THUNDERSTORMS WILL GRADUALLY SHIFT E THROUGH SAT NIGHT. A SURFACE TROUGH WILL MOVE OFF THE MEXICAN AND TEXAS COASTS EARLY SAT REACHING FROM S/CENTRAL LOUISIANA TO NE BAY OF CAMPECHE BY SUN AFTERNOON AND FROM THE MISSISSIPPI DELTA TO NW YUCATAN BY EARLY MON. THE TROUGH WILL THEN DRIFT E AND BECOME DIFFUSE OVER THE NE GULF BY LATE TUE AS A WEAK PRESSURE GRADIENT SETS UP ACROSS THE GULF IN ITS WAKE AND REMAIN IN PLACE THROUGH WED. CARIBBEAN SEA... AN UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE CARIBBEAN TO 70W AND IS ANCHORED BY AN UPPER HIGH OFF THE COAST OF GUATEMALA IN THE E PACIFIC REGION. THE UPPER TROUGH OVER THE W ATLC EXTENDS S OVER THE E CARIBBEAN E OF 70W. MODERATE TO EASTERLY TRADE WINDS ARE USHERING IN LOW LEVEL MOISTURE WITH SCATTERED SHOWERS W OF 70W WITH PATCHES OF HAZE BEING REPORTED OVER THE WINDWARD ISLANDS. AFTERNOON THUNDERSTORMS THAT WERE DEVELOPED OVER THE HISPANIOLA REMAIN ACROSS THE S PORTION OF THE ISLAND AND WITHIN 45 NM ALONG THE S COAST. WATER VAPOR SATELLITE IMAGERY SHOWS MODERATE SUBSIDENCE AND DRY STABLE AIR OVER THE REMAINDER OF THE CARIBBEAN SUPPORTING FAIR WEATHER TONIGHT. THE UPPER LEVEL TROUGH WILL SHIFT SLOWLY E THROUGH SUN NIGHT. W ATLC SURFACE RIDGE WILL STRENGTHEN ALLOWING THE TRADE WINDS TO INCREASE ACROSS MUCH OF THE CARIBBEAN THROUGH WED. ATLANTIC OCEAN... AN UPPER TROUGH IS OVER THE W ATLC BETWEEN 60W-75W EXTENDING S OVER THE E CARIBBEAN AND SUPPORTING A COLD FRONT THAT ENTERS THE W ATLC OVER BERMUDA TO 28N70W WHERE IT BECOMES STATIONARY AND DISSIPATES TO THE BAHAMA ISLANDS NEAR 26N77W. ISOLATED SHOWERS/ THUNDERSTORMS ARE WITHIN 175/200 NM E OF THE FRONT N OF 24N. A SURFACE RIDGE IS BUILDING W OF THE FRONT ANCHORED BY A 1022 MB HIGH OVER THE OHIO VALLEY. AN UPPER RIDGE IS JUST TO THE E EXTENDING FROM 20N60W TO BEYOND 32N56W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE FROM 21N62W TO 28N63W. A BROAD SURFACE RIDGE COVERS THE CENTRAL ATLC N OF 20N BETWEEN 35W-60W. AN UPPER LOW IS OVER THE E ATLC CENTERED NEAR 34N31W SUPPORTING A 1016 MB LOW NEAR 32N32W WITH AN OCCLUDED FRONT EXTENDING N AND A SURFACE TROUGH ENTERING THE DISCUSSION AREA NEAR 32N24W EXTENDING TO 25N27W. A JET STREAM IS TO THE E OF THE SURFACE TROUGH WITH WINDS OF 80 TO 110 WITHIN 150 NM OF LINE FROM 25N35W TO BEYOND 32N23W. THE LAST VISIBLE SATELLITE IMAGES SHOW SAHARAN DUST COVERING THE TROPICAL ATLC MAINLY S OF 20N TO THE MONSOON TROUGH/ITCZ E OF THE CARIBBEAN ISLANDS. THE WEAK COLD FRONT WILL CONTINUE TO WEAKEN THROUGH EARLY SAT AND BECOME STATIONARY FROM NEAR 32N62W TO 26N67W TO 20N74W BY LATE SAT AFTERNOON. THE FRONT WILL WEAKEN TO TROUGH SAT NIGHT INTO SUN AS IT MOVES INTO THE CENTRAL ATLC. A SURFACE RIDGE WILL BUILD W OVER CENTRAL AND W ATLC SAT THROUGH WED. A WEAK COLD FRONT WILL MOVE ACROSS THE SE U.S. MON AND APPROACH THE NE FLORIDA COAST LATE TUE AND WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW