000 WTPZ44 KNHC 310846 TCDEP4 TROPICAL STORM KEVIN DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142009 200 AM PDT MON AUG 31 2009 A 0216 UTC QUIKSCAT PASS CONFIRMED THAT KEVIN HAS MAXIMUM WINDS OF 35 KT CONFINED TO THE DEEP CONVECTION OVER THE NORTHWESTERN QUADRANT. THE MID-LEVEL CIRCULATION APPEARS TO BE DECOUPLING FROM THE LOW-LEVEL CENTER...WHICH IS ESTIMATED TO BE LOCATED ON THE SOUTHERN EDGE OF THE CONVECTION BASED ON RECENT MICROWAVE AND SCATTEROMETER PASSES. THE SIZE OF THE CONVECTIVE MASS HAS BEEN SHRINKING OVER THE PAST FEW HOURS...AND THIS MAY BE AN INDICATION THAT KEVIN MAY NOT CONTINUE AS A TROPICAL CYCLONE FOR MUCH LONGER. EVEN THOUGH SSTS ARE EXPECTED TO REMAIN WARM AND VERTICAL SHEAR SHOULD BE RELATIVELY LIGHT FOR ANOTHER 36 HOURS OR SO...ALL THE INTENSITY GUIDANCE SHOWS KEVIN WEAKENING OVER THE NEXT FEW DAYS. THE OFFICIAL FORECAST CONSERVATIVELY SHOWS KEVIN BECOMING A REMNANT LOW BY 48 HOURS WITH DISSIPATION BY 96 HOURS. THE MICROWAVE AND SCATTEROMETER PASSES HELPED LOCATE THE CENTER... AND THE INITIAL MOTION IS NOW ESTIMATED AT 015/5. KEVIN IS BEING STEERED SLOWLY NORTH-NORTHEASTWARD BETWEEN A MID-LEVEL ANTICYCLONE TO ITS SOUTHEAST AND A SHEAR AXIS TO ITS NORTHWEST. THE STEERING CURRENTS ARE EXPECTED TO REMAIN LIGHT OVER THE NEXT FEW DAYS...BUT THE MODEL GUIDANCE IS IN CLOSE AGREEMENT ON A SLOW NORTH TO NORTH-NORTHEASTWARD MOTION THROUGH 48 HOURS. THERE IS GREATER SPREAD IN THE MODEL ENVELOPE AFTER THAT POINT WITH SEVERAL MODELS SHOWING A WEST TO SOUTHWEST TURN...BUT THE OFFICIAL FORECAST FOLLOWS THE LEAD OF THE GFS...GFDL...AND NOGAPS WHICH SHOW KEVIN DISSIPATING AS EARLY AS 48-72 HOURS. FORECAST POSITIONS AND MAX WINDS INITIAL 31/0900Z 16.3N 121.7W 35 KT 12HR VT 31/1800Z 16.8N 121.4W 30 KT 24HR VT 01/0600Z 17.4N 121.0W 30 KT 36HR VT 01/1800Z 17.8N 120.7W 30 KT 48HR VT 02/0600Z 18.1N 120.5W 25 KT...REMNANT LOW 72HR VT 03/0600Z 18.5N 120.5W 20 KT...REMNANT LOW 96HR VT 04/0600Z...DISSIPATED $$ FORECASTER BERG