Hurricane JOHN
ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM HURRICANE JOHN DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112006 800 AM PDT WED AUG 30 2006 THE UNITED STATES AIR FORCE RECONNAISSANCE AIRCRAFT WAS ABLE TO INVESTIGATE JOHN THIS MORNING JUST AFTER THE EYE REAPPEARED ON SATELLITE IMAGERY. A 700 MB FLIGHT LEVEL WIND OF 126 KT WAS REPORTED ON THE OUTBOUND LEG NORTHEAST OF THE CENTER...THIS REDUCES TO 113 KT AT THE SURFACE...AND IS CONSISTENT WITH A DROPSONDE MEASUREMENT IN THE NORTHEAST EYEWALL. FURTHERMORE... DVORAK CLASSIFICATIONS FROM BOTH TAFB AND SAB WERE 6.0 OR 115 KT. THE INITIAL INTENSITY IS SET AT 115 KT FOR THIS ADVISORY...AND JOHN HAS NOW REACHED CATEGORY FOUR STATUS ON THE SAFFIR-SIMPSON HURRICANE SCALE. OUTFLOW IS WELL ESTABLISHED...THE SHEAR IS EXPECTED TO BE LOW...AND THE WATERS ARE EXPECTED TO REMAIN AROUND 30 DEGREES CELSIUS... CONSEQUENTLY THE OFFICIAL FORECAST ANTICIPATES ADDITIONAL STRENGTHENING AND MAINTAINS JOHN AS A CATEGORY FOUR THROUGH 48 HOURS. AFTER WHICH...GRADUAL WEAKENING IS FORECAST DUE TO THE HURRICANE INTERACTING WITH LAND AND EVENTUALLY ENCOUNTERING COOLER WATERS. THE INITIAL MOTION IS 305/10. JOHN SHOULD CONTINUE TO MOVE TO THE NORTHWEST AND PARALLEL VERY CLOSE TO THE WEST COAST OF MEXICO...AROUND THE SOUTHWESTERN PERIPHERY OF A MIDDLE- TO UPPER-LEVEL RIDGE OVER NORTHERN MEXICO. THE OFFICIAL TRACK FORECAST HAS BEEN ADJUSTED SLIGHTLY TO THE EAST OF THE PREVIOUS TRACK AND IS IN CLOSE AGREEMENT WITH THE DYNAMICAL MODEL CONSENSUS CONU. THERE REMAINS A HIGHER THAN NORMAL UNCERTAINTY IN THE TRACK AFTER THREE DAYS...AND THE GFDL MODEL STILL TAKES JOHN NORTHWESTWARD INTO THE GULF OF CALIFORNIA. THE WIND RADII HAVE BEEN ADJUSTED ACCORDINGLY FROM THE AIRCRAFT OBSERVATIONS. THE UPDATED TRACK FURTHER TO THE EAST AND THE EXPANDED WIND RADII HAVE PROMPTED THE GOVERNMENT OF MEXICO TO ADJUST THE WATCHES AND WARNINGS. FORECAST POSITIONS AND MAX WINDS INITIAL 30/1500Z 16.6N 102.3W 115 KT 12HR VT 31/0000Z 17.6N 103.6W 125 KT 24HR VT 31/1200Z 19.3N 105.6W 125 KT 36HR VT 01/0000Z 21.0N 107.3W 125 KT 48HR VT 01/1200Z 22.3N 108.7W 120 KT 72HR VT 02/1200Z 23.5N 111.5W 105 KT 96HR VT 03/1200Z 24.0N 115.0W 90 KT 120HR VT 04/1200Z 24.0N 119.0W 75 KT $$ FORECASTER MAINELLI/FRANKLIN NNNN