000 AXNT20 KNHC 210540 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUN 21 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. ...SPECIAL FEATURES... TROPICAL STORM CHRIS IS CENTERED NEAR 38.9N 46.4W AT 21/0300 UTC OR ABOUT ABOUT 550 NM SE OF CAPE RACE NEWFOUNDLAND MOVING E-NE AT 19 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF THE CENTER OVER THE S SEMICIRCLE AND WITHIN 60 NM OF THE CENTER OVER THE N SEMICIRCLE. A 1010 MB LOW IS CENTERED NEAR 25N86W AT 21/0300 UTC WITH A SURFACE TROUGH EXTENDING FROM 29N84W THROUGH THE SURFACE LOW TO THE NE YUCATAN NEAR 21N87W. STRONG UPPER LEVEL WINDS OVER THE GULF OF MEXICO ARE EXPECTED TO GRADUALLY DIMINISH IN A COUPLE OF DAYS AND SOME SLOW DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE BY THAT TIME AS THE DISTURBANCE MOVES SLOWLY NORTHWESTWARD TOWARD THE CENTRAL GULF OF MEXICO. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS WESTERN CUBA...SOUTHERN FLORIDA...THE CENTRAL BAHAMAS...AND THE YUCATAN PENINSULA THROUGH SATURDAY. BROAD AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE E GULF S OF 19N E OF 90W...NW CARIBBEAN N OF 18N W OF 77W...AND PORTIONS OF THE BAHAMA ISLANDS S OF 27N W OF 76W. ...TROPICAL WAVES... TROPICAL WAVE S OF THE CAPE VERDE ISLANDS EXTENDS FROM 12N26W TO 6N28W MOVING W 15-20 KT. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 8N-12N BETWEEN 20-28W. TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM PUERTO RICO NEAR 18N67W TO 13N68W MOVING WNW 25-30 KT. WAVE IS LOSING ITS DEFINITION WITH NO ASSOCIATED CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W TO 9N22W. THE ITCZ STARTS W OF THE TROPICAL WAVE NEAR 7N30W ALONG 7N45W TO INLAND OVER SOUTH AMERICA NEAR 5N54W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N TO INLAND OVER SW AFRICA E OF 10W TO THE PRIME MERIDIAN...FROM 5N-10N BETWEEN 13W-23W...AND FROM 5N-8N BETWEEN 30W-42W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM AN UPPER HIGH OVER THE N YUCATAN PENINSULA NW TO THE TEXAS COAST COVERING ALL BUT THE NE GULF. DIFFLUENCE ALOFT TO THE W OF THE UPPER RIDGE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-28N W OF 92W TO INLAND OVER MEXICO AND S TEXAS. AN UPPER TROUGH IS OVER THE NE GULF EXTENDING FROM AN UPPER LOW OVER THE FLORIDA PANHANDLE NEAR PENSACOLA SE TO NEAR FORT MYERS FLORIDA. THE ACTIVITY OVER THE E GULF IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. THE LOW/SURFACE TROUGH WILL SLOWLY MOVE W TO THE CENTRAL GULF THU THROUGH SAT POSSIBLY AS A TROPICAL CYCLONE. THE LOW IS THEN EXPECTED TO TRACK NE TO THE EASTERN GULF SUN AND MON. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED BY AN UPPER HIGH OVER THE N YUCATAN PENINSULA WITH A RIDGE AXIS EXTENDING E ALONG 20N GIVING THE CARIBBEAN NE TO ENE FLOW ALOFT. THE ACTIVITY IN THE NW CARIBBEAN IS DESCRIBED IN THE SPECIAL FEATURES ABOVE. AFTERNOON THUNDERSTORMS THAT DEVELOPED OVER COLOMBIA HAVE MOVED INTO THE S CARIBBEAN S OF 10N E OF 78W. THIS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES TONIGHT. THE TROPICAL WAVE WILL MOVE THROUGH THE CENTRAL CARIBBEAN TONIGHT AND THU THEN DISSIPATE OVER THE W CARIBBEAN THU NIGHT. A SECOND TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN SAT/SUN AND CENTRAL CARIBBEAN MON. ATLANTIC OCEAN... WEAK UPPER RIDGE EXTENDS FROM THE CENTRAL CUBA N TO THE GEORGIA COAST FURTHER ENHANCING THE ACTIVITY OVER FLORIDA DESCRIBED IN THE SPECIAL FEATURES ABOVE. A CUT OFF UPPER LOW IS CENTERED NEAR 31N67W WITH AN UPPER TROUGH EXTENDING SW TO 26N75W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 33N66W TO 25N72W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 22N-32N W OF 62W TO THE SURFACE TROUGH. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS AN UPPER RIDGE AXIS ALONG 20N TO 60W THEN ENE TO BEYOND 32N37W PROVIDING DIFFLUENCE ALOFT TO GENERATE ISOLATED SHOWERS/ THUNDERSTORMS WITHIN 120 NM OF LINE FROM 28N52W TO BEYOND 32N41W. A BROAD SURFACE RIDGE CONTINUES TO DOMINATE THE REMAINDER OF THE ATLC E OF 60W ANCHORED BY A PAIR OF 1022 MB HIGHS NEAR 30N34W AND 27N53W. THE SURFACE TROUGH WILL DRIFT NW THROUGH THU NIGHT WHILE WEAKENING. HIGH PRESSURE WILL BUILD ALONG 26N THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW