000 AXNT20 KNHC 182353 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 18 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC... ...TROPICAL WAVES... TROPICAL WAVE HAS MOVED OFF THE W COAST OF AFRICA ALONG 21W S OF 20N MOVING W NEAR 15 KT. LOW-MID LEVEL CYCLONIC CURVATURE IS EVIDENT IN SATELLITE IMAGERY AND SATELLITE DERIVED WINDS. A SURGE OF DEEP LAYER MOISTURE IS ALSO PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-18N BETWEEN 14W-23W...AND SW OF THE WAVE AXIS FROM 3N-9N BETWEEN 24W-30W. TROPICAL WAVE IS JUST E OF THE LESSER ANTILLES ALONG 61W S OF 19N MOVING W NEAR 15 KT. BROAD CYCLONIC FLOW ENCOMPASSES THE WAVE AXIS EVIDENT IN SATELLITE IMAGERY. A LARGE AREA OF DEEP LAYER MOISTURE ALSO ACCOMPANIES THE WAVE SEEN IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 14N-22N BETWEEN 54W-67W. GUSTY WINDS AND LOCALLY HEAVY RAINFALL ASSOCIATED WITH THIS SYSTEM COULD AFFECT THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO RICO...THE DOMINICAN REPUBLIC...HAITI...AND THE TURKS AND CAICOS ISLANDS DURING THE NEXT COUPLE OF DAYS. TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN ALONG 77W S OF 20N MOVING W 15-20 KT. WAVE LIES EMBEDDED WITHIN A LARGE AREA OF DEEP LAYER MOISTURE THAT IS ACROSS CENTRAL THE CARIBBEAN. SCATTERED MODERATE/STRONG CONVECTION IS FROM 14N-22N BETWEEN 70W-80W AFFECTING AREAS S OF WESTERN HISPANIOLA...JAMAICA AND EASTERN CUBA. TROPICAL WAVE IS OVER THE NW CARIBBEAN FROM WESTERN CUBA NEAR 23N82W TO EAST HONDURAS NEAR 15N85W MOVING W NEAR 5 KT. WAVE LIES EMBEDDED IN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE WRN CARIBBEAN. SATELLITE IMAGERY INDICATES BROAD CYCLONIC ROTATION IN THE VICINITY OF THE WAVE AXIS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 12N-25N BETWEEN 80W-91W INCLUDING INLAND PORTIONS OF CENTRAL AMERICA...THE YUCATAN PENINSULA...CUBA...AND THE STRAITS OF FLORIDA. ...ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 7N23W 8N30W 9N40W 7N50W 8N60W. MODERATE TO ISOLATED STRONG CONVECTION IS FROM 3N TO 9N BETWEEN 24W AND 30W. SCATTERED WEAK TO MODERATE CONVECTION IS WITHIN 100 NM ON EITHER SIDE OF THE ITCZ AXIS W OF 42W. ...DISCUSSION... GULF OF MEXICO... THE SURFACE TROUGH THAT HAS BEEN GENERATING THE CONVECTIVE WEATHER ACROSS THE GULF OVER THE PAST FEW DAYS IS NOW OVER THE FAR SW BASIN EXTENDING WITHIN 40 NM ALONG THE COAST OF MEXICO FROM 23N96W TO 18N95W...PRODUCING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 25N W OF 94W. AT THIS POINT...MOST OF THE MOISTURE AND ENERGY FROM THIS SYSTEM HAVE BEEN TRANSFERRED ALOFT TO THE NORTH CENTRAL GULF COAST AFFECTING THE COASTAL WATERS OF LOUISIANA AND MISSISSIPPI WITHIN 150 NM OFFSHORE WITH SCATTERED MODERATE TO ISOLATED HEAVY SHOWERS. A BROADER AREA OF LOWER PRESSURE/CYCLONIC FLOW ASSOCIATED WITH A TROPICAL WAVE CURRENTLY OVER THE NW CARIBBEAN IS STARTING TO ENTER THE SE GULF THROUGH THE YUCATAN CHANNEL...WESTERN CUBA...THE SOUTHERN FLORIDA PENINSULA INCLUDING THE STRAITS...GENERATING SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS S OF 27N E OF 88W. THIS SYSTEM WILL CONTINUE TO MOVE W WITH SHOWERS AND THUNDERSTORMS SPREADING ACROSS THE SOUTHERN HALF OF THE GULF OVER THE NEXT FEW DAYS. THE REMAINDER OF THE BASIN WILL CONTINUE UNDER MORE STABLE CONDITIONS WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE ESE FLOW. CARIBBEAN SEA... SATELLITE DATA INDICATES SIGNIFICANT MOISTURE AND UNSTABLE CONDITIONS ACROSS MUCH OF THE CARIBBEAN ASSOCIATED WITH A SERIES OF TROPICAL WAVES. SEE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. BESIDES THE TROPICAL WAVES...SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN S OF 13N W OF 75W ASSOCIATED WITH AN EXTENSION OF THE ITCZ ACROSS NICARAGUA TO NRN COLOMBIA. ALOFT...AN UPPER LEVEL LOW N OF PUERTO RICO IS PROVIDING A DIFFLUENT ZONE ALOFT OVER THE LEEWARD ISLANDS WHICH IS ENHANCING CONVECTION NEAR THE TROPICAL WAVE JUST E OF THE LESSER ANTILLES. EXPECT CONTINUED SHOWER ACTIVITY ACROSS MUCH OF THE BASIN AS THE TROPICAL WAVES PROGRESS WESTWARD BRINGING SIGNIFICANT MOISTURE AND CONVECTION ACROSS THE AREA. ATLANTIC OCEAN... SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH TROPICAL WAVES IN THE WRN AND CENTRAL CARIBBEAN ARE AFFECTING PORTIONS OF THE FAR WEST ATLANTIC INCLUDING THE BAHAMAS AND FLORIDA STRAITS. SCATTERED MODERATE TO ISOLATED HEAVY SHOWERS AND THUNDERSTORMS ARE FROM 18N TO 30N BETWEEN 60W AND 70W...DUE TO AN UPPER LEVEL LOW SPINNING NEAR 25N66W ENHANCING THE CONVECTION ASSOCIATED TO A TROPICAL WAVE JUST E OF THE LESSER ANTILLES. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1025 MB HIGH NEAR 30N55W AND A 1028 MB HIGH E OF THE AZORES NEAR 38W22N. A DRY SAHARAN AIR LAYER ACCOMPANIED BY DUST COVERS MUCH OF THE TROPICAL ATLC SUPPRESSING CONVECTION IN THIS REGION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA