000 WTPZ42 KNHC 210236 TCDEP2 HURRICANE IVO DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP122007 800 PM PDT THU SEP 20 2007 SATELLITE IMAGES INDICATE THAT A LARGE BURST OF CONVECTION IS NEAR THE CENTER OF IVO. EVEN THOUGH AN EYE IS NOT VISIBLE IN CONVENTIONAL IMAGERY...MICROWAVE DATA SHOW AN EYE WHICH HAS BEEN OCCASIONALLY OPEN. THERE HAS BEEN LITTLE CHANGE IN THE SATELLITE INTENSITY ESTIMATES AND THE INITIAL INTENSITY IS LEFT AT 70 KT. ALTHOUGH THE FORECAST SHEAR IS LIGHT AND THE WATER RELATIVELY WARM...NONE OF THE RELIABLE INTENSITY MODELS SHOW ANY STRENGTHENING WITH IVO. PERHAPS THIS IS DUE TO THE HURRICANE MOVING CLOSER TO THE RELATIVELY STABLE AIR TO THE NORTH. IN ANY EVENT...THE INTENSITY FORECAST IS ALMOST THE SAME AS THE PREVIOUS ONE IN THE SHORT-TERM...BUT A LITTLE LOWER BEYOND 2 DAYS BECAUSE MOST MODELS SHOW INCREASING SHEAR AND THE SYSTEM WILL LIKELY BE INTERACTING WITH LAND. SSMI AND AMSR-E MICROWAVE DATA SHOW THAT IVO IS MOVING FASTER TONIGHT TOWARD THE NORTH...350/8. THE TRACK FORECAST IS PROBLEMATIC TO SAY THE LEAST. FOR THE NEXT DAY OR SO...THE HURRICANE WILL BE TRAVELING NORTHWARD IN AN AREA OF WEAK STEERING CURRENTS BETWEEN A RIDGE OVER CENTRAL MEXICO AND A RATHER DEEP MIDDLE- TO UPPER-LEVEL LOW OFFSHORE OF SOUTHERN CALIFORNIA. THE MODELS ARE IN RATHER POOR AGREEMENT ON WHETHER IVO WILL EVENTUALLY GET CAUGHT UP IN THE SOUTHWESTERLY FLOW AHEAD OF THE LOW OR GET LEFT BEHIND IN THE AREA OF LIGHT STEERING CURRENTS. THE NOGAPS/UKMET/HWRF MODELS FAVOR THE SYSTEM GETTING CARRIED TO THE NORTHEAST RATHER QUICKLY AND IMPACTING BAJA CALIFORNIA...WHILE THE GFS/ECMWF/GFDN/GFDL MODELS DO NOT SHOW ANY LAND IMPACTS. THE OFFICIAL TRACK FORECAST IS A LITTLE FASTER IN THE FIRST DAY DUE TO THE INITIAL MOTION BUT IS CLOSE TO THE CONSENSUS IN THE LONG-TERM. GIVEN THE EXTREME UNCERTAINTY PRESENT IN THE OFFICIAL FORECAST AT THIS TIME...INTERESTS IN SOUTHERN BAJA CALIFORNIA SHOULD CLOSELY MONITOR THE PROGRESS OF IVO. FORECAST POSITIONS AND MAX WINDS INITIAL 21/0300Z 18.8N 113.4W 70 KT 12HR VT 21/1200Z 19.7N 113.5W 70 KT 24HR VT 22/0000Z 20.6N 113.1W 70 KT 36HR VT 22/1200Z 21.3N 112.8W 65 KT 48HR VT 23/0000Z 22.0N 112.5W 60 KT 72HR VT 24/0000Z 23.5N 112.0W 55 KT 96HR VT 25/0000Z 25.0N 111.5W 45 KT...INLAND OVER BAJA 120HR VT 26/0000Z 26.5N 111.5W 30 KT...INLAND OVER BAJA $$ FORECASTER BLAKE