000 AXNT20 KNHC 040539 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SUN NOV 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W TO 11N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 8N26W 12N38W 9N52W TO SOUTH AMERICA NEAR 9N61W. SCATTERED STRONG CONVECTION IS FROM 10N-14N BETWEEN 35W-41W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-10N BETWEEN 15W-32W. ...DISCUSSION... GULF OF MEXICO... THE UPPER RIDGE ANCHORED OVER CENTRAL AMERICA EXTENDS A RIDGE AXIS ACROSS THE YUCATAN PENINSULA ACROSS THE GULF TO THE BORDER OF LOUISIANA/TEXAS DRAWING TROPICAL MOISTURE ACROSS MEXICO INTO THE W GULF. A SURFACE RIDGE DOMINATES THE GULF ANCHORED BY A 1020 MB HIGH NEAR 28N88W. THE COMBINATION OF S SURFACE FLOW OVER THE NW GULF COUPLED WITH THE WESTERLY FLOW ALOFT IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 25N W OF 92W TO INLAND OVER TEXAS WITH ISOLATED SHOWERS S OF 25N W OF 90W. DRY STABLE AIR ALOFT REMAINS OVER THE E GULF LEAVING THE REMAINDER OF THE AREA WITH CLEAR SKIES AGAIN TONIGHT. SURFACE HIGH WILL WEAKEN THROUGH SUN THEN REORGANIZE ACROSS THE W ATLC SUN NIGHT ALLOWING A STRONG COLD FRONT TO RAPIDLY MOVE SE ACROSS THE GULF EARLY TUE THROUGH WED. HIGH PRESSURE WILL THEN SETTLE JUST N OF THE AREA LATE WED THROUGH THU. CARIBBEAN SEA... THE BROAD UPPER RIDGE THAT DOMINATES THE CARIBBEAN HAS SHIFTED W AND IS NOW ANCHORED OVER CENTRAL AMERICA AND EXTENDS A RIDGE AXIS ACROSS THE YUCATAN PENINSULA INTO THE GULF OF MEXICO. A SURFACE TROUGH IS IN THE SW CARIBBEAN EXTENDING FROM 18N84W THROUGH A WEAK 1009 MB LOW ALONG THE COAST OF NICARAGUA NEAR 12N83W TO 10N83W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 12N-20N BETWEEN 80W-87W. THE UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO ENHANCE THE ACTIVITY ASSOCIATED WITH THE SURFACE TROUGH. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER TONIGHT. THE SURFACE TROUGH WILL DRIFT W INLAND THROUGH SUN. A STRONG GULF OF MEXICO COLD FRONT IS EXPECTED TO MOVE INTO THE YUCATAN CHANNEL EARLY ON WED THEN BEGIN TO WEAKEN AS IT STALLS FROM E CUBA TO CENTRAL YUCATAN PENINSULA LATE WED AND THU. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE NW ATLC INTO THE DISCUSSION AREA N OF 30N W OF 50W SUPPORTING A COLD FRONT THAT ENTERS THE W ATLC OVER BERMUDA TO 31N69W. A PRE-FRONTAL SURFACE TROUGH EXTENDS THROUGH 32N57W ALONG 27N61W TO 25N68W. DRY STABLE AIR ALOFT IS OVER THE FAR W ATLC N OF 24N W OF 70W GIVING THE ARE REMARKABLY CLEAR SKIES TONIGHT. A BROAD UPPER RIDGE COVERS THE CENTRAL ATLC ANCHORED IN THE TROPICS NEAR 16N52W AND EXTENDING A RIDGE AXIS N TO BEYOND 32N43W. A SURFACE TROUGH IS ANALYZED TO THE W OF THIS UPPER RIDGE AXIS ALONG 29N50W 23N60W TO N OF HISPANIOLA NEAR 21N69W. THIS UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM 26N59W TO 30N52W AND SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 24N61W TO OVER HISPANIOLA NEAR 20N71W. A NARROW UPPER TROUGH IS OVER THE E ATLC WITH THE AXIS EXTENDING ALONG 30W TO 11N AND SUPPORTING A 1006 MB LOW NEAR 32N25W WITH A SURFACE TROUGH EXTENDING SW ALONG 26N31W TO 21N38W. AN UPPER RIDGE OVER AFRICA IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-32N BETWEEN THE COAST OF AFRICA AND 29W INCLUDING THE CANARY ISLANDS. THE PRE-FRONTAL SURFACE TROUGH WILL MEANDER AND SLOWLY DISSIPATE THROUGH MON. SURFACE RIDGE OVER THE GULF OF MEXICO WILL MOVE NE AND INTO TO THE W ATLC LATE SUN NIGHT. THE HIGH WILL QUICKLY SHIFT NE OF THE AREA BY TUE ALLOWING FOR A COLD FRONT TO MOVE INTO THE NW WATERS. THE FRONT IS EXPECTED TO REACH FROM NEAR 32N69W TO E CUBA BY LATE WED AS HIGH PRESSURE BUILDS IN BEHIND IT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW