000 AXNT20 KNHC 252344 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 25 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 IS ABOUT TO MOVE OFF THE W AFRICAN COAST AND WILL LIKELY BE ADDED ON THE NEXT ANALYSIS. TROPICAL WAVE PREVIOUSLY NEAR 29W HAS BEEN DROPPED ON THE SURFACE ANALYSIS AS OF 1800 UTC. THIS WAS BASED ON VARIED SOURCES OF DATA INCLUDED SAL ANALYSIS...SATELLITE IMAGERY...AND MODEL DATA THAT ALL POINT TO THE CONCLUSION THAT THE AREA OF CONVECTION SEEN ALONG THE ITCZ IN THIS LOCATION IS NOT INFLUENCED BY A TROPICAL WAVE...BUT LIKELY A WIND SURGE ALONG THE ITCZ AREA. TROPICAL WAVE IS ACROSS THE CENTRAL TRPCL ATLC ALONG 18N41W TO 10N43W MOVING W 10-15 KT. SATELLITE IMAGERY INDICATES BROAD LOW-LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS...WHICH IS ALSO INDICATED BY AN ASCAT SCATTEROMETER PASS FROM EARLIER TODAY. TOTAL PRECIPITABLE WATER IMAGERY SHOWS THAT THE WAVE LIES WITHIN A SURGE OF DEEP LAYER MOISTURE. ISOLATED MODERATE CONVECTION IS FROM 14N-17N BETWEEN 41W-43W. TROPICAL WAVE CONTINUES TO PUSH ACROSS CENTRAL CUBA ALONG 24N78W TO 17N80W MOVING W NEAR 20 KT. BROAD CYCLONIC FLOW IS AROUND THE WAVE AXIS. TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES THAT AN AREA OF ENHANCED MOISTURE COVERS THE NW CARIBBEAN AND ACROSS THE WATERS N OF CUBA. CURRENTLY SCATTERED MODERATE/STRONG CONVECTION IS FROM 17N-23N BETWEEN 74W-85W AFFECTING JAMAICA AND MUCH OF CUBA. A CLUSTER OF SIMILAR ACTIVITY IS ALSO ACROSS HAITI. EXPECT CONTINUED HEAVY SHOWERS/THUNDERSTORMS TO CONTINUE OVER CUBA AND SPREAD ACROSS THE STRAITS OF FLORIDA AND POSSIBLY S FLORIDA AS THE WAVE MOVES WWD. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 19N ALONG 18N15W 12N19W 8N27W. THE ITCZ CONTINUES FROM 8N27W TO 7N46W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 100 NM S OF THE AXIS BETWEEN 17W-26W. SIMILAR ACTIVITY IS FROM 7N-11N BETWEEN 35W-40W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING CONTINUES TO COVER THE GULF OF MEXICO THIS EVENING AROUND A PAIR OF 1018 MB HIGHS NEAR 21N97W AND 27N91W PROVIDING MOSTLY FAIR WEATHER ACROSS THE CENTRAL PORTIONS OF THE BASIN. THE RIDGE IS SUPPORTED BY A LARGE UPPER LEVEL RIDGE CENTERED OVER NRN TEXAS WHICH IS PROVIDING MAINLY NE FLOW ALOFT ACROSS THE BASIN. TOTAL PRECIPITABLE WATER IMAGERY CONTINUES TO SHOW HIGHER MOISTURE VALUES ACROSS THE NRN GULF WHICH COINCIDES WITH AN AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N BETWEEN 86W-95W. AN AREA OF STRONG SHOWERS/THUNDERSTORMS IS ALSO ACROSS SW FLORIDA WITH AN AREA OF LIGHTER ACTIVITY ACROSS NE FLORIDA. NUMEROUS SHOWERS/THUNDERSTORMS ARE ALSO NOTED ACROSS THE YUCATAN PENINSULA FROM 18N-22N BETWEEN 88W-90W. THIS ACTIVITY MAY BE ASSOCIATED WITH AN UPPER LEVEL TROUGH EXTENDING FROM N OF THE NW BAHAMAS NEAR 29N78W TO THE BAY OF CAMPECHE NEAR 20N92W. SHOWER ACTIVITY WILL BEGIN TO INCREASE OVER THE SE GULF AS MOISTURE ASSOCIATED WITH A TROPICAL WAVE ACROSS CUBA MOVES WWD TOWARDS THE AREA. SURFACE RIDGING WILL REMAIN ACROSS THE REMAINDER OF THE BASIN WITH HIGH MOISTURE VALUES ALSO REMAINING OVER THE NRN GULF INCREASING THE CHANCE OF PRECIPITATION. CARIBBEAN SEA... MOIST CONDITIONS ARE ACROSS THE NW CARIBBEAN AS A TROPICAL WAVE CURRENTLY ACROSS CENTRAL CUBA MOVES WWD. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. CURRENTLY...SCATTERED SHOWERS/THUNDERSTORMS COVER THE AREA FROM 17N-23N BETWEEN 74W-85W INCLUDING JAMAICA AND MUCH OF CUBA. AN UPPER LEVEL TROUGH EXTENDING FROM N OF THE NW BAHAMAS TO THE BAY OF CAMPECHE MAY BE ENHANCING SOME OF THIS ACTIVITY NEAR THE WAVE. THE REMAINDER OF THE BASIN IS UNDER MOSTLY FAIR CONDITIONS UNDER THE INFLUENCE OF DRY AIR ALOFT AROUND A WEAK UPPER LEVEL RIDGE EXTENDING FROM N OF HISPANIOLA NEAR 24N71W TO THE SRN WINDWARD ISLANDS NEAR 11N62W. A FEW ISOLATED SHOWERS ARE MOVING ACROSS THE WINDWARD ISLANDS FROM 13N-16N E OF 68W EMBEDDED WITHIN 15-20 KT ELY FLOW ACROSS THE ERN CARIBBEAN. TOTAL PRECIPITABLE WATER IMAGERY INDICATES SOME HIGHER MOISTURE VALUES IN THE AREA OF THE ISOLATED SHOWERS THAT SPREADS EWD INTO THE TROPICAL ATLC. EXPECT SHOWERS/THUNDERSTORMS TO CONTINUE ACROSS THE NW CARIBBEAN AS THE WAVE ACROSS CUBA MOVES WWD. THE ERN CARIBBEAN MAY SEE CONTINUE TO SEE ISOLATED SHOWERS DUE TO THE HIGHER MOISTURE VALUES ACROSS THE AREA. ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR SW ATLC S OF 28N W OF 75W ASSOCIATED WITH A TROPICAL WAVE ACROSS CUBA. BROAD SURFACE RIDGING CONTINUES TO DOMINATE THE REMAINDER OF THE ATLC ANCHORED BY A 1028 MB AZORES HIGH PROVIDING MOSTLY FAIR WEATHER BASIN-WIDE. ALOFT...AN UPPER LEVEL LOW COVERS THE FAR WRN ATLC CENTERED NEAR 29N78W WITH TROUGH AXIS EXTENDING TO THE BAY OF CAMPECHE. AN UPPER LEVEL RIDGE IS TO THE SE WITH AXIS ALONG 24N71W TO 11N62W. ANOTHER UPPER LEVEL LOW IS SPINNING IN THE CENTRAL ATLC NEAR 27N50W WITH AXIS EXTENDING TO E OF THE WINDWARD ISLANDS. THIS UPPER TROUGH SUPPORTS A SURFACE TROUGH JUST E OF THE WINDWARD ISLANDS ALONG 59W FROM 12N-18N WITH ISOLATED SHOWERS WITHIN 150 NM EITHER SIDE OF THE AXIS. AN UPPER LEVEL RIDGE COVERS THE ERN ATLC WITH TWO CENTERS NEAR 19N36W AND 26N12W. 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