000 WTPZ41 KNHC 101501 TCDEP1 TROPICAL STORM ODILE DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP162008 800 AM PDT FRI OCT 10 2008 TWO RECENT MICROWAVE PASSES PLACE THE CENTER OF ODILE JUST INSIDE THE NORTHEASTERN EDGE OF THE DEEP CONVECTION...AND THE CYCLONE IS SHOWING GOOD BANDING STRUCTURE. DVORAK T NUMBERS ARE UNCHANGED FROM 6 HOURS AGO. A QUIKSCAT PASS JUST IN SHOWS CORRECT AMBIGUITIES OF 40-45 KT...WITH PERHAPS ONE VALID VECTOR OF 45-50 KT. BASED ON THESE DATA...THE INTENSITY ESTIMATE IS HELD AT 50 KT. THE INITIAL MOTION IS 300/8. ODILE IS EXPECTED TO CONTINUE MOVING IN A GENERAL WEST-NORTHWESTWARD DIRECTION...ROUGHLY PARALLEL TO THE COAST OF MEXICO...AS THE CYCLONE IS STEERED AROUND THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE THAT EXTENDS ACROSS THE GULF OF MEXICO INTO CENTRAL AND NORTHERN MEXICO. EXCEPT FOR THE UKMET...WHICH LOSES THE VORTEX ALMOST IMMEDIATELY...MOST OF THE GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO FOR THE NEXT 36-48 HOURS. THERE IS SOME UNCERTAINTY AFTER THAT...WITH THE GFS AND ECMWF SHOWING INCREASED NORTHEASTERLY SHEAR THAT WEAKENS THE SYSTEM...WHICH IS FOLLOWED BY A TURN OF THE SHALLOWER VORTEX TO THE WEST. THE GUIDANCE ALSO SHOWS A WESTWARD EXTENTION OF THE RIDGE AFTER HURRICANE NORBERT CROSSES BAJA CALIFORNIA THAT WOULD FAVOR A TURN TO THE WEST AFTER 2-3 DAYS. ON THE OTHER HAND...THE BAM MODELS DO NOT SHOW THIS WESTWARD TURN. THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY THROUGH 48 HOURS AND IS ADJUSTED A LITTLE TO THE SOUTH AFTER THAT. HOWEVER...IT IS STILL NEAR THE NORTHERN EDGE OF THE GUIDANCE ENVELOPE. THE SHEAR IS NOT EXPECTED TO CHANGE MUCH OVER THE NEXT DAY OR TWO...SO SOME STRENGTHENING IS FORECAST IN GOOD AGREEMENT WITH THE SHIPS GUIDANCE. LATER IN THE FORECAST PERIOD AN INCREASE IN THE SHEAR IS EXPECT TO INDUCE A SLOW WEAKENING TREND. ONLY A VERY SMALL DEVIATION OF THE TRACK TO THE RIGHT WOULD BRING TROPICAL STORM FORCE WINDS ONSHORE...AND THUS A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE COAST OF MEXICO. FORECAST POSITIONS AND MAX WINDS INITIAL 10/1500Z 14.4N 97.3W 50 KT 12HR VT 11/0000Z 15.0N 98.4W 55 KT 24HR VT 11/1200Z 15.9N 100.2W 60 KT 36HR VT 12/0000Z 16.6N 101.9W 60 KT 48HR VT 12/1200Z 17.1N 103.3W 65 KT 72HR VT 13/1200Z 18.0N 105.5W 60 KT 96HR VT 14/1200Z 18.5N 107.5W 55 KT 120HR VT 15/1200Z 19.0N 109.5W 50 KT $$ FORECASTER FRANKLIN