000 AXNT20 KNHC 022340 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 02 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 2245 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 18N46W TO 10N44W MOVING W NEAR 20 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT THE WAVE LIES WITHIN A LARGE AND FAST MOVING SURGE OF DEEP LAYER MOISTURE. DUE TO A LARGE AREA OF SAHARAN DUST SURROUNDING THE WAVE...NO DEEP CONVECTION IS CURRENTLY NEAR THE WAVE. TROPICAL WAVE IS MOVING THROUGH THE CENTRAL CARIBBEAN 18N72W TO 12N72W MOVING W NEAR 15-20 KT. BROAD ENHANCED MOISTURE VALUES SURROUND THE WAVE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NEAR THE NRN EXTENT OF THE WAVE OVER HISPANIOLA FROM 18N-20N BETWEEN 71W-74W. SCATTERED MODERATE CONVECTION IS ALSO FROM 14N-17N BETWEEN 71W-72W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF SENEGAL AT 14N17W CONTINUING OVER ATLC WATERS ALONG 9N28W 9N38W. THE ITCZ BEGINS AT 9N38W CONTINUING ALONG 10N46W 8N58W. A LARGE CLUSTER OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS MOVING OFF THE AFRICAN COAST FORM 9N-16N BETWEEN 13W-18W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SCATTERED MODERATE CONVECTION IS FROM 6N-8N BETWEEN 28W-34W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE GULF OF MEXICO TODAY CENTERED AROUND A 1020 MB HIGH OFF THE W COAST OF FLORIDA NEAR 27N84W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER THE FLORIDA PANHANDLE NEAR 31N86W. MOSTLY DRY AIR COVERS THE BASIN...WHICH IS HELPING MAINTAIN FAIR CONDITIONS ACROSS THE GULF WATERS. HOWEVER...STRONG CLUSTERS OF SHOWERS/THUNDERSTORMS HAVE POPPED UP OVER THE FLORIDA PENINSULA AS WELL AS ACROSS MUCH OF THE YUCATAN PENINSULA AND INLAND MEXICO. THIS ACTIVITY IS LIKELY TYPICAL AFTERNOON CONVECTION DUE TO DAYTIME HEATING AND INSTABILITY. THE ACTIVITY OVER THE YUCATAN ALSO LIES UNDERNEATH A DIFFLUENT AREA ALONG AROUND AN UPPER LEVEL TROUGH EXTENDING FROM LOUISIANA TO THE SW GULF. UPPER LEVEL RIDGING ALSO COVERS THE FAR NW GULF. LIGHT ANTI-CYCLONIC WINDS ARE AROUND THE SURFACE HIGH INCREASING IN SPEED TO 15 KTS IN THE WRN GULF AND ALONG THE MEXICAN COAST. EXPECT SURFACE RIDGING TO REMAIN ACROSS THE BASIN THROUGH THE END OF THE WEEK. CARIBBEAN SEA... MOSTLY CLEAR SKIES AND FAIR WEATHER ARE ACROSS THE CENTRAL AND WRN CARIBBEAN WATERS DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH EXTENDING FROM ERN CUBA TO NRN COLOMBIA. HOWEVER...STRONG SHOWERS WITH ISOLATED THUNDERSTORMS COVER MUCH OF CENTRAL AMERICA AND THE IMMEDIATE COASTAL WATERS ESPECIALLY NICARAGUA. THIS ACTIVITY IS LIKELY IMPACTED BY DAYTIME HEATING ALONG WITH THE MONSOON TROUGH THAT EXTENDS S OF PANAMA TO NRN COLOMBIA. A TROPICAL WAVE APPROACHING THE CENTRAL CARIBBEAN IS SUPPORTING A CLUSTER OF SHOWERS/THUNDERSTORMS ACROSS HISPANIOLA WITH A FEW EXTENDING E OF THE WAVE AXIS TO NEAR 67W. THE WAVE ALSO LIES UNDER THE MOIST AND DIFFLUENT AREA ALOFT AROUND THE E SIDE OF THE UPPER TROUGH IN THE WRN AND CENTRAL CARIBBEAN WHICH IS CAUSING HIGH CLOUDS...AND MAY BE ENHANCING THE MOISTURE SIGNAL PRESENT ACROSS THE ERN HALF OF THE BASIN. THE FAR ERN CARIBBEAN IS EXPERIENCING MOSTLY FAIR CONDITIONS WITH SOME REPORTS OF DUST. AN UPPER LEVEL RIDGE COVERS THE ERN CARIBBEAN CENTERED NEAR 14N66W. EXPECT THE WAVE TO CONTINUE TO MOVE WWD DRAWING MOISTURE WITH IT. MOISTURE AHEAD OF THE NEXT TROPICAL WAVE MAY REACH THE ERN CARIBBEAN BY LATE TOMORROW. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE COVERS THE FAR WRN ATLC EXTENDING FROM THE NE GULF OF MEXICO SUPPORTING WEAK SURFACE RIDING AND MOSTLY FAIR CONDITIONS. A WEAK SURFACE TROUGH IS ACROSS THE CENTRAL BAHAMAS ALONG 25N76W TO 22N79W. MOST OF THE SHOWERS/THUNDERSTORMS WITH THE TROUGH HAVE NOW DISSIPATED. HOWEVER...AN UPPER LEVEL TROUGH THAT IS ABOVE THE SURFACE TROUGH IS PROVIDING DIFFLUENCE ALOFT TO THE E AND CAUSING ISOLATED SHOWERS/THUNDERSTORMS FROM 21N-25N BETWEEN 68W-76W. A SECOND UPPER TROUGH ALONG 57W SUPPORTS ANOTHER SURFACE TROUGH ALONG 32N59W TO 29N63W WITH NO SHOWER ACTIVITY ASSOCIATED WITH IS. AN UPPER LEVEL RIDGE IS BETWEEN THE TWO UPPER TROUGHS EXTENDING FROM THE ERN CARIBBEAN. FARTHER E...THERE IS ANOTHER PAIR OF UPPER LEVEL LOWS. THE FIRST IS CENTERED NEAR 31N40W AND IS SUPPORTING A SURFACE TROUGH ALONG 33N41W TO 27N40W. SCATTERED SHOWERS ARE E OF THE AXIS FROM 29N-31N BETWEEN 37W-40W. THE SECOND...BUT DRY...UPPER LEVEL LOW IS CENTERED NEAR 25N20W CAUSING NO APPARENT SIGNIFICANT WEATHER. AN UPPER LEVEL RIDGE IS BETWEEN THE TWO UPPER LOWS EXTENDING FROM THE AZORES ISLANDS TO NEAR 20N31W CONTINUING WWD TO NEAR 22N52W. A BROAD UPPER LEVEL RIDGE WELL N OF THE DISCUSSION AREA SUPPORTS A BROAD SURFACE RIDGE WHICH THE MULTITUDE OF SURFACE TROUGHS ARE EMBEDDED WITHIN ANCHORED BY A 1028 MB HIGH NEAR 38N36W. THE SURFACE RIDGE ACCOMPANIED BY A STABLE SAHARAN AIR LAYER IS SUPPORTING FAIR WEATHER ACROSS THE REMAINDER OF THE ATLC. THE LARGE AREA OF DUST EXTENDS ALL THE WAY FROM AFRICA TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON