000 AXNT20 KNHC 162354 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAY 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A STRONG TROPICAL WAVE IS CURRENTLY OVER W AFRICA ALONG 15N9W TO 7N9W CAUSING WIDESPREAD CONVECTION ACROSS W AFRICA. MODEL GUIDANCE INDICATES THE WAVE WILL MOVE OFF THE COAST AND OVER E ATLC WATERS WITHIN THE NEXT 24-36 HOURS. A TROPICAL WAVE IS ALONG 8N50W TO 4N52W MOVING W NEAR 15 KTS. WHILE THE WAVE WAS NOT EASILY IDENTIFIED OVER MUCH OF THE ATLC WATERS...UPPER AIR TIME SECTIONS FROM DAKAR SENEGAL INDICATE THAT THE WAVE MOVED OFF THE COAST AROUND 10/1200 UTC. THE CURRENT SPEED IS BASED OFF THIS ESTIMATION. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT AN AREA OF MAXIMUM MOISTURE IS NEAR THE WAVE AXIS AS WELL AS TO THE W OF THE AXIS. CURRENTLY SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MAINLY W OF THE AXIS FROM 2N-10N BETWEEN 50W-56W. MODERATE CONVECTION IS ALSO FARTHER W NEAR THE LESSER ANTILLES...BUT IS MORE ASSOCIATED WITH UPPER LEVEL DIFFLUENCE THAN THE WAVE. AS THE WAVE MOVES WWD THESE AREAS WILL LIKELY INTERACT AND COULD PRODUCE HEAVY RAINFALL OVER THE LESSER ANTILLES. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF GUINEA AT 11N15W AND CONTINUES OVER THE E ATLC WATERS TO 6N25W. THE ITCZ CONTINUES FROM 6N25W ALONG 4N38W 6N49W. THERE IS NO DEEP CONVECTION BESIDES NEAR THE TROPICAL WAVES MENTIONED ABOVE. ...DISCUSSION... THE GULF OF MEXICO... SWLY FLOW ALOFT COVERS THE GULF OF MEXICO THIS EVENING BETWEEN AN UPPER LEVEL RIDGE OVER THE W ATLC AND AN UPPER LEVEL TROUGH MOVING ACROSS THE ERN CONUS AND PARALLELING THE NRN GULF COAST. THE UPPER TROUGH SUPPORTS A SURFACE TROUGH THAT EXTENDS FROM THE FLORIDA PANHANDLE AT 31N85W TO THE YUCATAN PENINSULA ALONG 29N86W 25N87W 18N89W...AS OF 2100 UTC. SURFACE CONVERGENCE NEAR THE TROUGH ALONG WITH MOIST DIFFLUENT FLOW ALOFT IS HELPING PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS E OF THE TROUGH AXIS WITH THE STRONGEST ACTIVITY MOVING OVER CENTRAL FLORIDA. SCATTERED SHOWERS/THUNDERSTORMS HAVE ALSO FORMED ALONG THE COAST OF LOUISIANA LIKELY DUE TO DIFFLUENCE ALOFT AROUND THE UPPER TROUGH AXIS. THE REMAINDER OF THE WRN GULF IS UNDER MOSTLY FAIR CONDITIONS WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. WINDS ARE STRONGER IN THE ERN GULF NEAR THE TROUGH AS WELL AS IN THUNDERSTORMS. EXPECT MOIST CONDITIONS TO REMAIN OVER THE ERN GULF FOR AT LEAST THE NEXT 24 HOURS. THE CARIBBEAN SEA... SHOWERS/THUNDERSTORMS COVER MUCH OF THE YUCATAN PENINSULA AND NRN CENTRAL AMERICA ASSOCIATED WITH A SURFACE TROUGH IN THE ERN GULF OF MEXICO WHICH EXTENDS INTO THE YUCATAN PENINSULA. OVERCAST SKIES COVER THE REMAINDER OF THE NW CARIBBEAN. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM COSTA RICA ACROSS ERN CUBA AND INTO THE W ATLC WHILE AN UPPER LEVEL TROUGH EXTENDS DOWN THE LESSER ANTILLES. DRY AIR ALOFT COVERS THE AREA BETWEEN THESE TWO UPPER LEVEL FEATURES...WHICH IS HELPING MAINTAIN FAIR CONDITIONS ACROSS THE CENTRAL AND ERN CARIBBEAN. A FEW SHOWERS/THUNDERSTORMS ARE NOW APPROACHING THE LESSER ANTILLES FROM THE E ATLC ASSOCIATED WITH DIFFLUENCE ALOFT AROUND THE E SIDE OF THE UPPER TROUGH. ELY TRADEWIND FLOW COVERS MUCH OF THE AREA REACHING 15-20 KTS. THE ATLANTIC OCEAN... MOIST CONDITIONS WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS COVER THE FAR W ATLC W OF 72W. THIS IS ASSOCIATED WITH MOIST SWLY AND DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE ERN CONUS AND AN UPPER LEVEL RIDGE EXTENDING FROM THE CARIBBEAN ACROSS THE BAHAMAS TO 40N57W. THE UPPER RIDGE SUPPORTS A BROAD SURFACE RIDGE ANCHORED BY A 1032 MB HIGH AT 38N53W. THE RIDGE IS PROVIDING FAIR CONDITIONS ACROSS MUCH OF THE CENTRAL AND ERN ATLC EXCEPT FOR THE AREA E OF THE LESSER ANTILLES. AN UPPER LEVEL TROUGH EXTENDS FROM W OF THE AZORES ISLANDS TO THE NE CARIBBEAN AND DOWN THE LESSER ANTILLES...WHICH IS PROVIDING DIFFLUENCE ALOFT OVER THE AREA E OF THE ISLANDS. THIS IS RESULTING IN WIDESPREAD SHOWERS/POSSIBLE THUNDERSTORMS S OF 17N BETWEEN 52W-61W. A TROPICAL WAVE IS LOCATED TO THE SE OF THIS AREA AND THE WAVE MAY INTERACT WITH THE UPPER TROUGH AS IT MOVES WWD. OVER THE TROPICAL ATLC...AN UPPER LEVEL RIDGE EXTENDS FROM NEAR 7N32W ACROSS THE CAPE VERDE ISLANDS TO NW AFRICA. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY ALONG WITH GOES-R ENHANCEMENTS INDICATE THAT A LARGE AREA OF DUST HAS EMERGED OFF THE COAST OF AFRICA EXTENDING TO 36W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON