000 AXNT20 KNHC 231155 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT AUG 23 2008 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... RADAR AND SURFACE DATA INDICATE THAT THE CENTER OF FAY HAS AGAIN MADE LANDFALL...THIS TIME JUST SOUTHWEST OF CARRABELLE FLORIDA AROUND 0600 UTC. THIS MARKS FAY'S FOURTH LANDFALL IN FLORIDA OVER THE PAST 6 SIX DAYS...AN UNUSUAL FEAT FOR ANY TROPICAL CYCLONE. AT 23/1200 UTC FAY IS CENTERED INLAND OVER THE CENTRAL FLORIDA PANHANDLE ABOUT 20 MILES/35 KM SOUTHEAST OF PANAMA CITY FLORIDA...NEAR 29.9N 85.3W MOVING WEST AT 6 KT...AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 24 TO 48 HOURS. ON THE FORECAST TRACK...FAY WILL BE NEAR OR OVER THE GULF COAST OF THE WESTERN FLORIDA PANHANDLE TODAY AND TONIGHT...AND NEAR OR OVER THE GULF COAST OF MISSISSIPPI AND ALABAMA ON SUNDAY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24 TO 48 HOURS...AND FAY IS EXPECTED TO REMAIN A TROPICAL STORM INTO SUNDAY. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. OVER THE NEXT TWO DAYS...FAY IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES ACROSS THE WESTERN PORTION OF THE NORTHERN FLORIDA PENINSULA...THE FLORIDA PANHANDLE...SOUTHWESTERN GEORGIA...AND THE SOUTHERN HALF OF BOTH MISSISSIPPI AND ALABAMA...WITH ISOLATED MAXIMUM AMOUNTS OF 15 INCHES POSSIBLE. ADDITIONAL RAINFALL ACCUMULATIONS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE REMAINDER OF THE FLORIDA PENINSULA AND SOUTHEASTERN GEORGIA. ISOLATED TORNADOES ARE POSSIBLE TODAY AND TONIGHT IN PORTIONS OF NORTHERN FLORIDA...SOUTHERN GEORGIA...AND SOUTHERN ALABAMA. PRESENTLY DOPPLER RADAR SHOWS RAINBANDS ASSOCIATED WITH THE CIRCULATION OF FAY OVER N FLORIDA...THE FLORIDA PANHANDLE...S GEORGIA AND PARTS OF ALABAMA. A BAND OF SHOWERS WITH ISOLATED TSTMS IS ALONG THE GEORGIA/SOUTH CAROLINA BORDER. NEW CELLS ARE FORMING ALONG THE WEST COAST OF FLORIDA ALL THE WAY SOUTH TO THE FLORIDA KEYS UNDER A WEST AND SW FLOW. ...TROPICAL WAVES... A TROPICAL WAVE HAS RECENTLY EMERGED OFF THE COAST OF W AFRICA AND IS NOW ALONG 22W S OF 19N MOVING W AT 10-15 KT. THE 23/0000 UTC DAKAR VERTICAL SOUNDING SHOWED THE PASSAGE OF THE WAVE VERY CLEAR. AN EARLIER QSCAT PASS AND FIRST VIS IMAGERY FOR THE DAY REVEAL A BROAD AREA OF CYCLONIC TURNING JUST SOUTH OF THE CAPE VERDE ISLANDS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE AHEAD OF THE WAVE LINE AND WITHIN 200 NM OF THE SOUTHERN CAPE VERDE ISLANDS. A TROPICAL WAVE IS ALONG 44W/45W S OF 20N. SCATTERED MODERATE CONVECTION IS NOTED NEAR THE NORTHERN END OF THE WAVE AXIS FROM 18N-21N BETWEEN 43W-48W. SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS UNLIKELY DURING THE NEXT COUPLE OF DAYS AS THE WAVE MOVES WESTWARD AT ABOUT 15 KT. THE 1009 MB AREA OF LOW PRESSURE IS RELOCATED NEAR 11N55 BASED ON LATEST SATELLITE PHOTOS. CONVECTION IS ON THE INCREASE AROUND THE LOW CENTER. GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT COUPLE OF DAYS AS IT MOVES GENERALLY WESTWARD AT 10 TO 15 MPH. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINS AND GUSTY WINDS ARE EXPECTED TO SPREAD OVER PORTIONS OF THE WINDWARD AND LEEWARD ISLANDS TODAY. A TROPICAL WAVE IS OVER THE E CARIBBEAN ALONG 62W S OF 16N MOVING SLOWLY WWD. SCATTERED SHOWERS AND TSTMS ARE WITHIN 100 NM EITHER SIDE OF THE WAVE AXIS. A TROPICAL WAVE IS OVER CENTRAL AMERICA AND THE EPAC ALONG 87W/88W S OF 15N MOVING W 15-20 KT. MOST OF THE CONVECTION ASSOCIATED WITH THE WAVE IS ON THE PACIFIC SIDE NEAR THE INTERSECTION OF THE WAVE AXIS AND THE ITCZ. ...THE ITCZ... THE ITCZ IS CENTERED ALONG 12N16W 12N30W 14N42W 13N50W 12N54W. BESIDES THE CONVECTION MENTIONED ON THE TROPICAL WAVE SECTION... A LARGE CLUSTER OF MODERATE TO STRONG CONVECTION IS INLAND OVER WEST AFRICA APPROACHING THE COASTLINE. ISOLATED TO SCATTERED MODERATE CONVECTION IS FROM 4N-7N BETWEEN 36W-42W. ...DISCUSSION... GULF OF MEXICO... T.S. FAY REMAINS THE MAIN FEATURE OF INTEREST OVER THE GULF REGION AND THE STATE OF FLORIDA. IT IS MOVING SOUTH OF A LOW/MID-LEVEL RIDGE OVER THE EASTERN UNITED STATES. SEE SPECIAL FEATURES FOR DETAILS. A WEAK RIDGE ANCHORED ON A 1015 MB HIGH NEAR 29N93W DOMINATES THE WESTERN HALF OF THE GULF WHILE MOST OF THE EASTERN HALF REMAINS UNDER THE INFLUENCE OF THE OVERALL CIRCULATION OF FAY GIVING THE AREA NW TO W WINDS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER THE DEEP SOUTH AND NE MEXICO LIKELY DUE TO UPPER DIFFLUENCE BETWEEN AN UPPER-LEVEL LOW SPINNING OVER THE STATE OF CHIHUAHUA MEXICO AND AN UPPER-LEVEL HIGH OVER CENTRAL MEXICO. THIS HIGH DOMINATES THE WESTERN GULF. AN INVERTED TROUGH IS OVER THE CENTRAL GULF EXTENDING FROM AN UPPER LOW NEAR 24N88W TO THE E PORTION OF THE BAY OF CAMPECHE WHERE THERE IS SOME SHOWER ACTIVITY. ANOTHER UPPER-LEVEL HIGH CENTERED OVER WESTERN CUBA COVERS THE SE GULF. A SMALL AREA OF SHOWER WITH EMBEDDED TSTMS HAS DEVELOPED NEAR 27N88W. CARIBBEAN SEA... THE SUBTROPICAL RIDGE EXTENDS OVER THE GREATER ANTILLES PRODUCING MODERATE ELY TRADE WINDS. AN UPPER-LEVEL TROUGH EXTENDS FROM AN UPPER LOW OVER THE W ATLC NEAR 21N65W THROUGH THE MONA PASSAGE TO THE SW CARIBBEAN SEPARATING AN UPPER RIDGE ANCHORED OVER WRN CUBA AND THE FLORIDA STRAITS AND A SECOND UPPER RIDGE ANCHORED OVER THE FAR SE CARIBBEAN. THIS TROUGH IS HELPING TO INDUCE SOME SHOWER ACTIVITY OVER THE E CARIBBEAN BUT MAINLY SOUTH OF PUERTO RICO. A TROPICAL WAVE IS OVER THE E CARIBBEAN. SEE ABOVE. MOISTURE FROM THIS FEATURE IS EXPECTED TO REACH THE UK/US VIRGIN ISLANDS AND PUERTO RICO LATE TODAY. AN AREA OF SHOWERS AND TSTMS HAS DEVELOPED OVER THE SW CARIBBEAN THANKS TO DIFFLUENT PATTERN ALOFT AND THE CLOSE PROXIMITY OF THE ITCZ. A SMALL AREA OF SHOWERS IS BETWEEN THE CAYMAN ISLANDS AND JAMAICA. LOW TOPPED SHOWERS ARE SEEN OVER THE REMAINDER OF THE BASIN. ATLANTIC OCEAN... THE AZORES HIGH DOMINATES THE FORECAST AREA PRODUCING MOSTLY EASTERLY SURFACE FLOW OVER THE ATLANTIC PARTICULARLY FROM 20N-32N BETWEEN W AFRICA AND 60W. SHOWER ACTIVITY HAS DIMINISHED OVER THE W ATLC AS FAY CONTINUES TO MOVE WWD OVER THE FLORIDA PANHANDLE. IN THE UPPER LEVELS...AN UPPER-LEVEL HIGH SITUATED OVER WRN CUBA EXTENDS A RIDGE NWD OVER THE BAHAMAS AND PART OF THE W ATLC. AN UPPER-LEVEL TROUGH ENTERS THE AREA NEAR 32N68W THEN CONTINUES MAINLY S TO ANOTHER UPPER LOW LOCATED N OF PUERTO RICO NEAR 21N65W. UPPER DIFFLUENCE AHEAD OF THE TROUGH IS GENERATING AN AREA OF SHOWERS WITH EMBEDDED TSTMS N OF 23N BETWEEN 60W-70W. A SFC TROUGH IS ANALYZED OVER THAT AREA AND RUNS FROM 31N63W TO 24N68W. AN UPPER LEVEL HIGH LOCATED NEAR 27N45W DOMINATES THE CENTRAL ATLC. A LARGE UPPER-LEVEL LOW IS OVER THE E ATLANTIC NEAR 29N25W. $$ GR