000 WTNT42 KNHC 020256 TCDAT2 TROPICAL STORM GUSTAV DISCUSSION NUMBER 34 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008 1100 PM EDT MON SEP 01 2008 THE RADAR PRESENTATION OF GUSTAV HAS CONTINUED TO DEGRADE THIS EVENING AS THE STORM HAS MOVED INLAND OVER LOUISIANA. RECENT MAXIMUM DOPPLER VELOCITIES FROM THE LAKE CHARLES RADAR HAVE BEEN AROUND 65-70 KT AT ABOUT 4500 FT. THIS EQUATES TO ABOUT 50 KT AT THE SURFACE...THEREFORE GUSTAV IS DOWNGRADED TO A TROPICAL STORM. GUSTAV SHOULD CONTINUE WEAKENING AND IT IS EXPECTED THAT IT WILL BECOME A TROPICAL DEPRESSION ON TUESDAY... AND A REMNANT LOW IN A COUPLE OF DAYS. THE INITIAL MOTION ESTIMATE IS 315/11...A LITTLE SLOWER THAN BEFORE. THE FORWARD MOTION OF GUSTAV IS FORECAST TO SLOW DOWN MORE DURING THE NEXT DAY OR TWO AS A LOW-LEVEL RIDGE BUILDS OVER THE NORTH-CENTRAL UNITED STATES. THE FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY FOR THE FIRST COUPLE OF DAYS...BUT SHOWS A LITTLE MORE NORTHEASTWARD MOTION AT DAYS 3 AND 4. MOST OF THE GLOBAL MODELS ARE NOW SUGGESTING THAT THE GUSTAV'S CIRCULATION WILL BECOME ELONGATED AS IT INTERACTS WITH A FRONTAL BOUNDARY OVER THE CENTRAL UNITED STATES. THE UPDATED FORECAST NOW CALLS FOR THE REMNANTS GUSTAV TO BECOME MERGE WITH THIS FRONTAL BOUNDARY IN ABOUT 5 DAYS...IF NOT A LITTLE SOONER. INDICATIONS ARE THAT THE STORM SURGE FLOODING ALONG THE NORTHERN GULF COAST IS BEGINNING TO SUBSIDE. THE MAIN THREAT FROM GUSTAV NOW SHIFTS TO THE POTENTIAL OF HEAVY RAINFALL OVER PORTIONS OF THE SOUTH-CENTRAL UNITED STATES DURING THE NEXT FEW DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 02/0300Z 31.1N 92.7W 50 KT 12HR VT 02/1200Z 32.0N 93.7W 35 KT...INLAND 24HR VT 03/0000Z 32.7N 94.6W 25 KT...INLAND 36HR VT 03/1200Z 33.1N 95.2W 25 KT...INLAND REMNANT LOW 48HR VT 04/0000Z 33.7N 95.6W 20 KT...INLAND REMNANT LOW 72HR VT 05/0000Z 35.0N 95.5W 20 KT...INLAND REMNANT LOW 96HR VT 06/0000Z 36.0N 95.0W 20 KT...INLAND REMNANT LOW 120HR VT 07/0000Z...MERGED WITH FRONT $$ FORECASTER BROWN/FRANKLIN