000 AXNT20 KNHC 232351 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT JUL 23 2011 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 2300 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 17N32W TO 9N37W MOVING W NEAR 15 KT. SATELLITE IMAGERY INDICATES BROAD CYCLONIC FLOW AROUND THE WAVE AXIS. TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE THAT EXTENDS TO 20N. ISOLATED CLUSTERS OF MODERATE/STRONG CONVECTION ARE FROM 11N-13N BETWEEN 34W-37W. ACTIVE TROPICAL WAVE IS ACROSS THE ERN CARIBBEAN FROM 20N62W TO 10N65W. DEEP LAYER MOISTURE ASSOCIATED WITH THIS WAVE HAS PRECEDED THE WAVE AXIS FOR THE PAST FEW DAYS. EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY...THIS ENHANCED MOISTURE NOW EXTENDS ACROSS MUCH OF THE NE CARIBBEAN AND IS COLLOCATED WITH LARGE AREAS OF CONVECTION. CURRENTLY...MODERATE/STRONG CONVECTION COVERS THE AREA FROM 14N-21N BETWEEN 61W-74W IMPACTING THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA. THE NE ISLANDS LIKELY WILL CONTINUE TO RECEIVE HEAVY SHOWERS/THUNDERSTORMS OVER THE NEXT DAY OR SO AS THE WAVE CONTINUES TO MOVE WWD. TROPICAL WAVE IS IN THE BAY OF CAMPECHE ALONG 23N95W TO 16N95W MOVING W NEAR 12 KT. DRY AIR ALOFT ACROSS THE WRN BAY OF CAMPECHE HAS DAMPENED THE WAVE. IT IS LIKELY THAT THIS WAVE IS IN THE PROCESS OF DISSIPATING AND WILL BE DROPPED ON THE NEXT ANALYSIS. CURRENTLY AN AREA OF STRONG CONVECTION IS AT THE SRN TIP OF THE WAVE OVER INLAND MEXICO FROM 16N-17N BETWEEN 93W-95W. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 18N TO THE COAST OF SRN SENEGAL NEAR 12N17W TO 10N26W. THE ITCZ CONTINUES FROM 10N26W ALONG 13N33W 9N43W 10N60W. SCATTERED MODERATE/STRONG CONVECTION IS MOVING OFF THE W AFRICA COAST FROM 8N-11N BETWEEN 14W-16W. ISOLATED MODERATE CONVECTION IS FROM 5N-10N BETWEEN 21W-27W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 41W-47W. ...DISCUSSION... GULF OF MEXICO... A NEARLY DISSIPATED TROPICAL WAVE IS IN THE BAY OF CAMPECHE CAUSING NO SIGNIFICANT WEATHER. A CLUSTER OF SHOWER/THUNDERSTORMS IS NOTED OVER THE NRN YUCATAN PENINSULA FROM 20N-22N BETWEEN 88W-91W. THE REMAINDER OF THE BASIN IS UNDER WEAK SURFACE RIDGING EXTENDING FROM THE ATLC ALONG 27N. HOWEVER...MUCH OF THE ERN GULF OF MEXICO IS SPOTTED WITH ISOLATED SHOWERS/THUNDERSTORMS N OF 25N E OF 90W. RADAR IMAGERY INDICATES SOME STRONG STORMS ARE MOVING TOWARD THE WRN COAST OF FLORIDA. THIS ACTIVITY ACROSS THE NE GULF IS ASSOCIATED WITH AN AREA OF ENHANCED MOISTURE INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. ALOFT...MAINLY ELY FLOW COVERS THE NRN HALF OF THE BASIN AROUND THE BASE OF AN UPPER LEVEL RIDGE CENTERED OVER WRN KENTUCKY. AN UPPER LEVEL LOW COVERS THE SW GULF CENTERED NEAR 22N98W. A SECOND INVERTED UPPER TROUGH COVERS THE FAR SE GULF EXTENDING FROM THE NW CARIBBEAN. EXPECT THE TROPICAL WAVE IN THE SW CARIBBEAN TO DISSIPATE SHORTLY. THE MOISTURE ACROSS THE NE GULF IS EXPECTED TO DRIFT WWD OVER THE NEXT 24 HOURS AND WILL LIKELY SUPPORT ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE N CENTRAL GULF. CARIBBEAN SEA... A FEW ISOLATED CLUSTERS OF SHOWERS/THUNDERSTORMS ARE ACROSS CUBA AND JAMAICA THIS EVENING WITH THE REMAINDER OF THE WRN CARIBBEAN UNDER MOSTLY FAIR CONDITIONS. SHOWERS/THUNDERSTORMS ARE ALSO ACROSS THE MAJORITY OF PANAMA ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS SRN COSTA RICA TO NRN COLOMBIA. THE ERN CARIBBEAN IS BEING IMPACTED BY A TROPICAL WAVE W OF THE WINDWARD ISLANDS. STRONG SHOWERS/THUNDERSTORMS ARE ACROSS MUCH OF THE NE ISLANDS N OF 14N E OF 74W INCLUDING HISPANIOLA...PUERTO RICO...AND THE VIRGIN ISLANDS. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. ALOFT...AN UPPER LEVEL TROUGH COVERS THE WRN CARIBBEAN WITH A BROAD CENTER NEAR 17N79W. A WEAK UPPER RIDGE COVERS THE ERN CARIBBEAN CENTERED NEAR 20N60W. EXPECT THE NE AND N CENTRAL CARIBBEAN TO REMAIN MOIST WITH THE POSSIBILITY OF HEAVY SHOWERS/THUNDERSTORMS AS THE TROPICAL WAVE W OF THE WINDWARD ISLANDS CONTINUES MOVING WWD. ATLANTIC OCEAN... THE MAJORITY OF THE ATLC IS DOMINATED BY BROAD SURFACE RIDGING ANCHORED BY A 1026 MB HIGH NEAR 30N55W...AND A 1031 MB AZORES HIGH NEAR 39N28W PROVIDING FAIR WEATHER BASIN-WIDE. SCATTERED SHOWERS/THUNDERSTORMS ARE NOTED N OF THE ERN CARIBBEAN S OF 21N BETWEEN 60W-72W ASSOCIATED WITH A TROPICAL WAVE W OF THE WINDWARD ISLANDS. ALOFT...AN UPPER LEVEL LOW IS OVER THE W ATLC NEAR 30N71W. AN UPPER LEVEL RIDGE IS CENTERED JUST N OF THE LEEWARD ISLANDS NEAR 20N60W. A PAIR OF UPPER LEVEL LOWS COVER THE ERN ATLC CENTERED NEAR 33N42W AND 35N28W. A FEW ISOLATED SHOWERS ARE NOTED N OF 29N BETWEEN 46W-54W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON