000 WTNT42 KNHC 111444 TCDAT2 TROPICAL DEPRESSION GABRIELLE DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072007 1100 AM EDT TUE SEP 11 2007 THUNDERSTORM ACTIVITY CONTINUES OVER THE SOUTHEASTERN PORTION OF GABRIELLE. HOWEVER...A 1000 UTC QUIKSCAT OVERPASS INDICATES THAT THE CIRCULATION HAS BECOME ILL-DEFINED AND ELONGATED SOUTHEAST TO NORTHWEST. IN FACT...THE VORTICITY CENTER THAT HAS BEEN TRACKED IN SATELLITE IMAGERY OVERNIGHT IS LOCATED AT THE SOUTHEASTERN END OF A TROUGH CHARACTERIZED BY LIGHT AND VARIABLE WINDS. SINCE A WELL-DEFINED SURFACE CIRCULATION NO LONGER EXISTS...THIS SYSTEM NO LONGER QUALIFIES AS A TROPICAL CYCLONE AND THIS WILL BE THE LAST ADVISORY ISSUED ON GABRIELLE. AN ILL-DEFINED REMNANT LOW COULD PERSIST FOR A FEW MORE HOURS BUT SHOULD DISSIPATE IN THE INCREASING SOUTHWESTERLY FLOW AHEAD OF A DEVELOPING EXTRATROPICAL LOW OVER EASTERN NORTH AMERICA. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. FORECAST POSITIONS AND MAX WINDS INITIAL 11/1500Z 39.6N 65.3W 30 KT...DISSIPATING 12HR VT 12/0000Z 40.9N 61.4W 25 KT...REMNANT LOW 24HR VT 12/1200Z...DISSIPATED $$ FORECASTER BROWN