000 WTPZ44 KNHC 051438 TCDEP4 TROPICAL STORM MARIE DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142008 800 AM PDT SUN OCT 05 2008 DEEP CONVECTION ASSOCIATED WITH MARIE CONTINUES TO BE RATHER MINIMAL AND IS CONFINED TO THE SOUTHERN SEMICIRCLE OF THE CIRCULATION. DVORAK CURRENT INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 35 KT. HOWEVER THE APPEARANCE OF THE CYCLONE ON SATELLITE IMAGES HAS CHANGED LITTLE FROM EARLIER THIS MORNING WHEN AN ASCAT PASS SUGGESTED THAT THE INTENSITY WAS ABOUT 40 KT SO THE LATTER VALUE IS USED FOR THE ADVISORY WIND SPEED. SEA SURFACE TEMPERATURES BENEATH MARIE ARE NOT EXPECTED TO DECREASE OVER THE NEXT COUPLE OF DAYS...HOWEVER THE STABLE AND DRY AIR THAT THE SYSTEM IS EMBEDDED IN SHOULD INDUCE WEAKENING. MARIE IS FORECAST TO DEGENERATE INTO A REMNANT LOW WITHIN 2 DAYS. THE NHC INTENSITY FORECAST IS IN GOOD AGREEMENT WITH THE NUMERICAL INTENSITY CONSENSUS FORECAST...ICON. THE SHIPS MODEL SUGGESTS THAT MARIE COULD DISSIPATE SOONER THAN INDICATED HERE. AFTER THE MAINLY NORTHWARD TREK OBSERVED OVER THE PAST DAY OR SO...THE CYCLONE APPEARS TO BE DRIFTING WESTWARD AND THE MOTION IS ESTIMATED TO BE AROUND 270/2. ALTHOUGH A MID-LEVEL RIDGE TO THE NORTH WOULD INDUCE A GENERALLY WESTWARD MOTION FOR A DEEP TROPICAL CYCLONE...MARIE IS NOT EXPECTED TO BE A DEEP SYSTEM. IN FACT...SOME OF THE GLOBAL MODELS SHOW A DECOUPLING OF MARIE WITH THE LOWER-TROPOSPHERIC VORTEX BEING DRAWN SOUTHWARD AND EVEN SOUTHEASTWARD INTO THE FLOW TO THE WEST OF NORBERT WHILE THE MID-LEVEL CENTER MOVES OFF TO THE WEST. THE OFFICIAL FORECAST IS A COMPROMISE OF THE VARIOUS OBJECTIVE GUIDANCE MODEL TRACKS AND IS CLOSE TO THE PREVIOUS ONE...AND TO THE DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 05/1500Z 18.9N 122.3W 40 KT 12HR VT 06/0000Z 18.9N 122.7W 35 KT 24HR VT 06/1200Z 18.8N 123.6W 30 KT 36HR VT 07/0000Z 18.6N 124.5W 30 KT 48HR VT 07/1200Z 18.2N 125.2W 25 KT...REMNANT LOW 72HR VT 08/1200Z 17.7N 126.0W 20 KT...REMNANT LOW 96HR VT 09/1200Z 17.0N 127.0W 20 KT...REMNANT LOW 120HR VT 10/1200Z...DISSIPATED $$ FORECASTER PASCH