000 AXNT20 KNHC 042349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAY 04 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 AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W ALONG 9N17W TO 5N19W WHERE THE ITCZ AXIS CONTINUES ALONG 5N27N 3N36W TO SOUTH AMERICA NEAR 2N51W. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN 90/120 NM OF LINE FROM 3N11W TO INLAND OVER LIBERIA AND GUINEA NEAR 6N10W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM S OF THE ITCZ BETWEEN 34W-47W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM S MEXICO AND THE BAY OF CAMPECHE TO THE N GULF COAST OVER SE LOUISIANA. A MID/UPPER LEVEL SHORTWAVE TROUGH EXTENDS OVER THE FLORIDA PENINSULA TO CENTRAL CUBA LEAVING A LINGERING SURFACE TROUGH IN THE E GULF ALONG 87W BETWEEN 25N-29W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 24N-27N BETWEEN 84W-87W. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS THE FLORIDA PENINSULA TO 90W WITH A WEAKNESS IN THE IMMEDIATE VICINITY OF THE ABOVE SURFACE TROUGH. THE REMAINDER OF THE GULF IS UNDER CLEAR SKIES THIS EVENING. THE SURFACE TROUGH IS EXPECTED TO DRIFT W AND DISSIPATE TONIGHT INTO SAT. THE W ATLC SURFACE RIDGE WILL WEAKEN THROUGH THE WEEKEND. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM THE TROPICAL ATLC OVER THE CARIBBEAN WITH THE AXIS EXTENDING ALONG 11N/12N BETWEEN THE WINDWARD ISLANDS AND NICARAGUA WITH NEAR ZONAL WESTERLY FLOW ALOFT COVERING THE REMAINDER OF THE CARIBBEAN BASIN. A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC NEAR 23N59W INTO THE CARIBBEAN BETWEEN THE VIRGIN ISLANDS AND PUERTO RICO GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90/120 NM EITHER SIDE OF THE TROUGH AXIS. AFTERNOON THUNDERSTORMS HAVE DEVELOPED ACROSS CUBA...HISPANIOLA...AND JAMAICA AND COULD PRODUCE ISOLATED SHOWERS/THUNDERSTORMS ALONG THE IMMEDIATE COASTLINES. SCATTERED TO HEAVY SHOWERS WITH SCATTERED TO NUMEROUS THUNDERSTORMS ARE INLAND OVER NW VENEZUELA... COLOMBIA...PANAMA...AND COSTA RICA INTO THE SW CARIBBEAN S OF 12N BETWEEN 70W-80W AND ALONG THE IMMEDIATE COAST OF THE REMAINDER OF PANAMA AND ALL OF COSTA RICA. THE UPPER RIDGE IS ENHANCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE SE CARIBBEAN S OF 14N W OF 65W TO ACROSS THE WINDWARD ISLANDS. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS EVENING. WEAK SURFACE TROUGH WILL REMAIN NEAR STATIONARY THROUGH SUN THEN SHIFT SE TO N LEEWARDS BY WED. ATLANTIC OCEAN... A MID/UPPER LEVEL SHORTWAVE TROUGH EXTENDS OVER THE FLORIDA PENINSULA TO CENTRAL CUBA. A SURFACE RIDGE DOMINATES THE W ATLC ANCHORED BY A 1021 MB HIGH NEAR 29N78W. A LARGE UPPER LOW SE OF NOVA SCOTIA CANADA IS SUPPORTING A COLD FRONT THAT ENTERS THE CENTRAL ATLC NEAR 32N44W ALONG 28N50W TO 29N60W WHERE IT DISSIPATES ALONG 26N67W TO 27N71W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM SE OF THE FRONT E OF 53W. A SECOND SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1020 MB HIGH NEAR 27N26W. AN UPPER RIDGE IS ANCHORED IN THE TROPICAL ATLC NEAR 7N41W EXTENDING A RIDGE AXIS W INTO THE S CARIBBEAN ACROSS THE WINDWARD ISLANDS. A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC NEAR 23N59W INTO THE CARIBBEAN BETWEEN THE VIRGIN ISLANDS AND PUERTO RICO GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90/120 NM EITHER SIDE OF THE TROUGH AXIS. A BROAD AREA OF DENSE CLOUD COVER AND EMBEDDED SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVERS THE AREA FROM 10N-25N BETWEEN 50W AND THE LESSER ANTILLES. CENTRAL ATLC COLD FRONT WILL CONTINUE TO MOVE SE WEAKENING AND ENTERING INTO THE E ATLC TONIGHT. WEAK SURFACE RIDGE WILL SHIFT S ALONG 27N SUN AS STRONGER COLD FRONT ENTERS THE W ATLC LATE SUN...EXTENDING ALONG 28N LATE MON THEN WEAKEN ALONG 24N E OF BAHAMAS BY LATE TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW