000 AXNT20 KNHC 200000 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 19 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 2350 UTC... ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 30W S OF 21N MOVING W 15-20 KT. SATELLITE IMAGERY INDICATES CLEAR LOW-MID LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS CONFIRMED BY EARLIER SCATTEROMETER DATA AS WELL AS SATELLITE DERIVED WINDS. A SURGE OF DEEP LAYER MOISTURE IS ALSO PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS W OF THE WAVE AXIS FROM 3N-8N BETWEEN 30W-35W. SCATTERED WEAK CONVECTION IS ELSEWHERE WITHIN 200 NM ON EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE IS OVER THE EAST/CENTRAL CARIBBEAN ALONG 71W S OF 21N MOVING W NEAR 15 KT. LOW-MID LEVEL CYCLONIC FLOW IS IN THE NORTHERN EXTENSION OF THE WAVE AXIS EVIDENT IN SATELLITE AND RADAR IMAGERY. THE WAVE LIES UNDERNEATH AN AREA OF DIFFLUENCE ALOFT. THIS DIFFLUENCE ALOFT IS ENHANCING A LARGE AREA OF CONVECTION NEAR THE WAVE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 15N-23N BETWEEN 55W-72W...IMPACTING THE NORTHERN LEEWARD ISLANDS...VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA. THIS WAVE WILL LIKELY CONTINUE TO BRING HEAVY RAINFALL AND GUSTY WINDS TO THESE AREAS OVER THE NEXT COUPLE OF DAYS. TROPICAL WAVE IS IN THE NW CARIBBEAN FROM WESTERN CUBA NEAR 22N83W TO EAST CENTRAL NICARAGUA NEAR 13N84W MOVING W NEAR 8 KT. WAVE LIES EMBEDDED WITHIN A LARGE AREA OF DEEP LAYER MOISTURE THAT IS MOVING ACROSS THE WESTERN CARIBBEAN. MID-LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS INDICATED BY SATELLITE IMAGERY. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ACROSS THE NW CARIBBEAN FROM 14N-26N BETWEEN 75W-87W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA...THE YUCATAN PENINSULA... CUBA...SOUTHERN FLORIDA AND THE STRAITS. TROPICAL WAVE IS ACROSS THE CENTRAL GULF OF MEXICO FROM 27N90W TO 17N92W MOVING W NEAR 15 KT. WAVE LIES AHEAD OF A MAXIMUM IN DEEP LAYER MOISTURE THAT COVERS THE ERN GULF EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. A MID/UPPER LEVEL LOW IS SPINNING N OF THE YUCATAN PENINSULA NEAR 24N90W WHICH IS PROVIDING AN AREA OF DIFFLUENCE ALOFT AND ENHANCING CONVECTION NEAR THE WAVE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 15N-28N BETWEEN 86W-93W...INCLUDING INLAND PORTIONS OF GUATEMALA AND MEXICO S OF 21N. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE WESTERN AFRICA COASTLINE OF GUINEA NEAR 10N14W...WESTWARD ALONG 7N20W 5N30W 7N40W 10N50W 10N60W. SCATTERED MODERATE TO HEAVY SHOWERS ARE WITHIN 120 NM OFF THE COASTS OF GUINEA...GUINEA-BISSAU..SENEGAL AND THE GAMBIA S OF 14N DUE TO A MESOSCALE COMPLEX IS EMERGING TO THE ATLANTIC BASIN. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 3N TO 8N BETWEEN 30W AND 35W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ELSEWHERE WITHIN 100 NM ON EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IN THE CENTRAL GULF OF MEXICO ALONG 90W S OF 28N IS THE MAIN FEATURE ACROSS THE BASIN ENHANCING SHOWERS AND THUNDERSTORMS WITHIN 140 NM ON EITHER SIDE OF THE WAVE AXIS. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. AS OF 2200 UTC...A NEARLY STATIONARY SURFACE TROUGH IS ANALYZED IN THE SW GULF ALONG 23N93W TO 19N94W SUPPORTING ISOLATED SHOWERS AND THUNDERSTORMS WITHIN 75 NM EITHER SIDE OF THE AXIS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO ALONG THE EASTERN TEXAS AND WESTERN LOUISIANA COASTS N OF 28N BETWEEN 91W AND 95W. THIS ACTIVITY IS ASSOCIATED WITH A SHORTWAVE UPPER LEVEL TROUGH THAT PARALLELS THE COASTLINE. EXPECT THE TROPICAL WAVE OVER THE CENTRAL GULF TO CONTINUE TO MOVE W WITH SHOWERS/THUNDERSTORMS SPREADING ACROSS THE CENTRAL AND WESTERN GULF OVER THE NEXT FEW DAYS. FURTHERMORE...ANOTHER TROPICAL WAVE CURRENTLY OVER THE NW CARIBBEAN IS STARTING TO SPREAD CONVECTION TO SE GULF THROUGH THE YUCATAN CHANNEL...WESTERN CUBA...AND ACROSS THE SOUTHERN FLORIDA PENINSULA INCLUDING THE STRAITS. THIS SYSTEM WILL CONTINUE TO MOVE WNW WITH SHOWERS AND THUNDERSTORMS SPREADING ACROSS THE SE GULF OVER THE NEXT FEW DAYS. CARIBBEAN SEA... SATELLITE DATA INDICATES SIGNIFICANT MOISTURE AND UNSTABLE CONDITIONS OVER THE WEST AND NE CARIBBEAN ASSOCIATED WITH A SERIES OF TROPICAL WAVES. SEE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE W CARIBBEAN W OF 75W N OF 13N...AND OVER THE NE CARIBBEAN N OF 16N E OF 75W. WATER VAPOR IMAGERY INDICATES AN AREA OF DRY AIR OVER THE S CENTRAL AND SE CARIBBEAN WHICH IS KEEPING CONDITIONS FAIR ACROSS THESE AREAS. EXPECT CONTINUED SHOWER ACTIVITY ACROSS MUCH OF THE W AND N/NE BASIN AS THE TROPICAL WAVES MOVE WESTWARD BRINGING SIGNIFICANT MOISTURE AND CONVECTION ACROSS THE AREA. ATLANTIC OCEAN... SCATTERED SHOWERS AND THUNDERSTORMS ARE N OF CUBA AND 0VER THE BAHAMAS TO 25N W OF 70W. ANOTHER AREA OF SIMILAR CONVECTION IS FOUND N OF HISPANIOLA...PUERTO RICO...AND NE OF THE LESSER ANTILLES S OF 23N W OF 55W. THESE AREAS OF CONVECTION ARE ASSOCIATED WITH A SERIES OF TROPICAL WAVES IN THE E AND NW CARIBBEAN. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1025 MB HIGH NEAR 32N55W AND A 1027 MB HIGH S OF THE AZORES NEAR 35W29N. 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