000 AXNT20 KNHC 240004 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 23 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. ...SPECIAL FEATURES... TROPICAL STORM BONNIE WAS DOWNGRADED TO TROPICAL DEPRESSION AT 2100 UTC DURING LANDFALL OVER SOUTHERN FLORIDA PENINSULA. AS OF JUL 24 AT 0000 UTC...BONNIE IS OVER THE FAR EASTERN GULF OF MEXICO CENTERED NEAR 26.4N 82.5W MOVING WNW NEAR 16 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. THIS SYSTEM IS EMBEDDED IN A REGION OF DEEP LAYER MOISTURE AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. WATER VAPOR IMAGERY INDICATES AN BROAD UPPER LEVEL LOW SPINNING NEAR 27N92W. THIS UPPER LEVEL FEATURE IS PROVIDING CONSIDERABLE MOISTURE ALOFT INTO BONNIE AND FURTHER ENHANCING THE CONVERGENCE WITH THIS SYSTEM...PRODUCING A BROAD AREA OF SCATTERED MODERATE TO STRONG CONVECTION FROM 21N TO 30N BETWEEN 78W AND 85W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TILTED TROPICAL WAVE EXTENDS ALONG 18N32W 13N32W 8N35W MOVING W 5 TO 10 KT. SATELLITE DERIVED WINDS INDICATE LOW-LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS IN THE NORTHERN EXTENT OF THE WAVE. THE WAVE ALSO LIES AHEAD OF A SURGE IN DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...THIS WAVE IS FOUND WITHIN A BROAD AREA OF SAHARAN AIR LAYER SUPPRESSING ANY DEEP CONVECTION WITHIN THE WAVE AXIS AND SURROUNDINGS OF IT. TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES ALONG 59W S OF 20N MOVING W 5 TO 10 KT. THE WAVE CONTINUES TO PROPAGATE WWD ALONGSIDE A MAXIMUM IN DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS ALSO SHOW WEAK CYCLONIC CURVATURE IN THE VICINITY OF THE WAVE AXIS. SAHARAN AIR LAYER IS IN THE VICINITY OF THE WAVE. THEREFORE...THIS WAVE IS ONLY GENERATING ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS FROM 10N TO 20N BETWEEN 58W AND 63W. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE WESTERN AFRICAN COAST OF GUINEA NEAR 10N14W...WESTWARD ALONG 11N20W 14N30W 10N40W 10N50W 12N55W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 80 NM ON EITHER SIDE OF THE ITCZ EAST OF 24W. SCATTERED WEAK CONVECTION IS WITHIN 100 NM ON EITHER SIDE OF THE ITCZ WEST OF 24W. ...DISCUSSION... THE GULF OF MEXICO... SCATTERED GUSTY SHOWERS AND THUNDERSTORMS ASSOCIATED WITH TROPICAL DEPRESSION BONNIE CONTINUE TO IMPACT THE EASTERN GULF OF MEXICO. FOR MORE INFORMATION REGARDING BONNIE...SEE SPECIAL FEATURES ABOVE. A SURFACE TROUGH EXTENDS INTO THE NE GULF ACROSS THE FLORIDA PANHANDLE ALONG 31N85W TO 29N87W. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 40 NM OF THE AXIS. SCATTERED SHOWERS AND THUNDERSTORMS ARE ALSO ACROSS THE SOUTHWESTERN GULF WEST OF 91W SOUTH OF 23N. THIS ACTIVITY IS ASSOCIATED WITH AN AREA OF LOW PRESSURE THAT HAS MOVED INLAND OVER MEXICO. WATER VAPOR IMAGERY SHOWS DRY AIR ALOFT WRAPPING AROUND AN UPPER LEVEL LOW SPINNING NEAR 27N92W...KEEPING MUCH OF THE CENTRAL AND NORTHWEST GULF UNDER CLEAR SKIES. EXPECT SHOWER AND THUNDERSTORMS TO CONTINUE TO IMPACT THE EASTERN GULF WATERS AS BONNIE MOVES WEST-NORTHWEST TO NEAR THE COASTAL WATERS OF MISSISSIPPI...ALABAMA...AND WESTERN FLORIDA PANHANDLE OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER OVER THE NORTHERN CARIBBEAN AND INLAND PORTIONS OF THE GREATER ANTILLES NORTH OF 14N BETWEEN 64W AND 80W. THIS GROUP OF ISLANDS HAVE ALREADY RECEIVED CONSIDERABLE AMOUNTS OF RAINFALL FROM WHAT IS NOW TROPICAL DEPRESSION BONNIE. THE CONTINUATION OF RAINFALL ACROSS THESE AREAS INCREASES THE THREAT OF FLOODING AND POTENTIAL MUDSLIDES IN AREAS OF HIGH SATURATED TERRAIN. BROAD CYCLONIC CIRCULATION ALOFT AROUND AN UPPER LEVEL LOW SPINNING NORTH OF THE CARIBBEAN SEA NEAR 20N68W IS PRODUCING ALL THIS WEATHER OVER THIS REGION. DRY AIR INTRUSION FROM THE NORTH CENTRAL ATLANTIC IS FURTHER MAINTAINING THE UPPER LOW AND ENHANCING THE CONVECTION GENERATED BY IT. EXPECT SHOWERS AND THUNDERSTORMS TO CONTINUE OVER THE MENTIONED AREA AS THE UPPER LEVEL LOW MOVES SW TOWARDS THE SE BAHAMAS. A TROPICAL WAVE IS JUST EAST OF THE LESSER ANTILLES GENERATING ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE FAR EASTERN CARIBBEAN EAST OF 63W. THE ATLANTIC OCEAN... ONLY A FEW SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS REMAIN OVER THE NORTHERN BAHAMAS NORTH OF 24N FROM THE PASSAGE OF TROPICAL DEPRESSION BONNIE...NOW OVER THE EASTERN GULF WATERS. DRY AIR ALOFT COVERS MUCH OF THE WESTERN ATLC KEEPING CONDITIONS FAIR. HOWEVER...BROAD CYCLONIC CIRCULATION ALOFT AROUND AN UPPER LEVEL LOW SPINNING NEAR 20N68W IS PRODUCING SHOWERS AND THUNDERSTORMS ACROSS PUERTO RICO AND HISPANIOLA SOUTH OF 22N BETWEEN 63W-73W. DRY AIR INTRUSION FROM THE NORTH CENTRAL ATLANTIC IS FURTHER MAINTAINING THE UPPER LOW AND ENHANCING THE CONVECTION GENERATED BY IT. FARTHER EAST...SURFACE RIDGING DOMINATES THE REMAINDER OF THE BASIN ANCHORED BY A 1031 MB HIGH CIRCULATING OVER THE AZORES NEAR 38N27W PROVIDING FAIR CONDITIONS ACROSS THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA