000 AXNT20 KNHC 161052 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI MAR 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 8N13W TO 4N16W WHERE THE ITCZ AXIS CONTINUES ALONG 1N22W 1N35W THEN S OF THE EQUATOR NEAR 41W INTO SOUTH AMERICA NEAR 2S44W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 60 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 17W-21W AND FROM 4N TO S OF THE EQUATOR BETWEEN 23W-35W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE EXTENDS ACROSS MEXICO INTO THE CENTRAL PLAIN STATES GIVING THE GULF NW FLOW ALOFT. A WEAK SURFACE TROUGH IS MOVING W ACROSS THE SE GULF AND AT 16/0900 UTC EXTENDS FROM 25N85W TO JUST N OF THE YUCATAN CHANNEL NEAR 22N86W GENERATING ISOLATED SHOWERS FROM 22N-25N BETWEEN 80W-88W INCLUDING THE FLORIDA KEYS. A SURFACE RIDGE DOMINATES THE GULF EXTENDING FROM THE W ATLC ALONG THE N GULF COAST TO GALVESTON TEXAS. THIS IS LEAVING THE GULF UNDER CLEAR SKIES AGAIN THIS MORNING. SURFACE RIDGE WILL REMAIN THROUGH TUE. CARIBBEAN SEA... AN UPPER TROUGH EXTENDS ACROSS THE W ATLC INTO THE NW CARIBBEAN ACROSS CENTRAL CUBA TO THE GULF OF HONDURAS COVERING THE AREA N OF 15N W OF 80W. A BROAD UPPER RIDGE ANCHORED OVER THE TROPICAL ATLC DOMINATES THE REMAINDER OF THE CARIBBEAN. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR PREVAIL ACROSS THE CARIBBEAN WITH THE EXCEPTION OF THE S CARIBBEAN WHERE ISOLATED SHOWERS ARE S OF 13N BETWEEN 60W-75W INCLUDING THE WINDWARD AND ABC ISLANDS. TIGHT PRESSURE GRADIENT IS MAINTAINING FRESH TO STRONG NE TO E TRADE WINDS ACROSS THE BASIN. THESE TRADE WINDS CONTINUE TO BANK LOW CLOUDS WITH SCATTERED SHOWERS OVER THE SW CARIBBEAN S OF 13N BETWEEN 76W-80W TO INLAND OVER PANAMA. SCATTERED SHOWERS ARE OROGRAPHICALLY INDUCED OVER THE HIGHER ELEVATIONS OF HISPANIOLA AND PORTIONS OF CENTRAL AMERICA FROM NICARAGUA TO GUATEMALA LEAVING THE REMAINDER OF THE CARIBBEAN WATERS WITH MOSTLY FAIR WEATHER AGAIN THIS MORNING. LITTLE CHANGE IS EXPECTED THROUGH TUE. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS ACROSS THE W ATLC FROM AN UPPER LOW SE OF NOVA SCOTIA THROUGH 32N68W OVER THE N BAHAMA ISLANDS AND CENTRAL CUBA INTO THE NW CARIBBEAN SUPPORTING A SURFACE TROUGH IS E OF THE BAHAMA ISLANDS EXTENDING FROM 28N72W TO 22N67W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 24N-28N BETWEEN 64W-74W. A SECOND SURFACE TROUGH EXTENDS FROM 30N57W TO 25N54W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 26N-28N BETWEEN 50W-56W. A SURFACE RIDGE COVERS THE REMAINDER OF THE W ATLC ANCHORED N OF THE DISCUSSION AREA BY A 1028 MB HIGH NEAR 33N73W. A BROAD UPPER TROUGH IS OVER THE E ATLC N OF 25N E OF 36W TO OVER AFRICA. A BROAD UPPER RIDGE ANCHORED IN THE TROPICAL ATLC COVERS THE REMAINDER OF THE ATLC BASIN. A WEAKENING SURFACE RIDGE COVERS THE REMAINDER OF THE CENTRAL AND E ATLC ANCHORED N OF THE DISCUSSION AREA BY A 1029 MB HIGH IN THE CENTRAL ATLC AND A 1029 MB HIGH IN THE E ATLC. W ATLC SURFACE RIDGE WILL BEGIN TO SHIFT SLOWLY SW AND WEAKEN TONIGHT THROUGH MON BEFORE BEING REPLACED BY STRONGER SURFACE RIDGE BUILDING ACROSS W ATLC AND INTO FLORIDA MON NIGHT AND TUE. SURFACE TROUGH E OF THE BAHAMAS WILL SHIFT SLOWLY W AND WEAKEN THROUGH SUN. CENTRAL ATLC SURFACE TROUGH WILL SLOWLY DRIFT W THROUGH SUN AND DISSIPATE ON MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW