000WTPZ42 KNHC 200231TCDEP2HURRICANE IVO DISCUSSION NUMBER 7NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP122007800 PM PDT WED SEP 19 2007SATELLITE PRESENTATION HAS CONTINUED TO IMPROVE WITH AN AREA OF DEEPCONVECTION NEAR THE CENTER AND A WELL ESTABLISHED UPPER-LEVELOUTFLOW. DVORAK T-NUMBERS FROM BOTH TAFB AND SAB HAVE INCREASED TO4.0 AND A RECENT MICROWAVE PASSAGE SHOWS A WELL DEFINED RING OFCONVECTION RESEMBLING AN EYEWALL. ON THIS BASIS...IVO HAS BEENUPGRADED TO A 65 KNOT HURRICANE. THERE IS A CHANCE FOR IVO TOSTRENGTHEN SOME DURING THE NEXT 24 TO 36 HOURS. THEREAFTER...AGRADUAL WEAKENING IS FORECAST SINCE THE SHEAR IS EXPECTED TOINCREASE...AS INDICATED BY THE SHIPS MODELS. IN FACT...SOME OF THEGLOBAL MODELS WEAKEN OR LOSE THE CYCLONE BEYOND DAY 3. ONLY THEGFDL KEEPS IVO AS A HURRICANE ALL THE WAY THROUGH THE COAST OFMAINLAND MEXICO. WE WILL CONTINUE TO CLOSELY MONITOR FUTURE GFDLRUNS. IVO APPEARS TO BE MOVING TOWARD THE NORTHWEST OR 315 DEGREES AT 8KNOTS AROUND THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE.THIS RIDGE WILL BE ERODED BY THE DEVELOPMENT OF A LARGEMID-LATITUDE TROUGH...RESULTING IN VERY WEAK STEERING CURRENTS. IVOIS EXPECTED TO TURN NORTHWARD VERY SLOWLY AND THEN TURN MORE TO THENORTH-NORTHEAST WITHIN THE LIGHT FLOW TO THE SOUTHEAST OF THEMID-LATITUDE TROUGH. THE TRACK FORECAST BASICALLY FOLLOW THESOLUTION OF THE GLOBAL MODELS WITH THE EXCEPTION OF THE GFSFORECAST WHICH APPEARS TO BE TOO FAR TO THE WEST.INTERESTS IN SOUTHERN BAJA CALIFORNIA SHOULD CLOSELY MONITOR THEPROGRESS OF IVO DURING THE NEXT FEW DAYS.FORECAST POSITIONS AND MAX WINDSINITIAL 20/0300Z 16.1N 112.4W 65 KT 12HR VT 20/1200Z 16.9N 113.2W 70 KT 24HR VT 21/0000Z 18.0N 113.5W 75 KT 36HR VT 21/1200Z 19.0N 113.5W 75 KT 48HR VT 22/0000Z 20.0N 113.0W 70 KT 72HR VT 23/0000Z 21.5N 112.0W 60 KT 96HR VT 24/0000Z 22.5N 111.0W 50 KT120HR VT 25/0000Z 24.0N 110.0W 50 KT$$FORECASTER AVILA