000 WTNT41 KNHC 021435 TCDAT1 HURRICANE FELIX DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062007 1100 AM EDT SUN SEP 02 2007 FELIX IS A WELL-ORGANIZED HURRICANE WITH A SYMMETRIC-APPEARING CLOUD STRUCTURE AND STRONG UPPER-TROPOSPHERIC OUTFLOW. THE EYE IS BECOMING WELL-DEFINED ON VISIBLE IMAGES AND THE CURACAO RADAR IS SHOWING A RATHER CLASSIC PRESENTATION...WITH THE SOUTHERN EYEWALL PASSING WELL NORTH OF ARUBA. THERE HAVE BEEN NO RECENT EYE PENETRATIONS BY HURRICANE HUNTER AIRCRAFT BUT BASED ON THE INCREASINGLY WELL-DEFINED EYE...THE CURRENT INTENSITY IS ADJUSTED...PROBABLY CONSERVATIVELY...TO 90 KT. THE HURRICANE IS FORECAST TO REMAIN IN AN EXTREMELY LOW WIND SHEAR ENVIRONMENT AND TO MOVE OVER WATERS OF INCREASINGLY HIGH OCEANIC HEAT CONTENT. THEREFORE I SEE NO REASON WHY FELIX WILL NOT BECOME A MAJOR HURRICANE WITHIN 12 HOURS OR SO. THE OFFICIAL INTENSITY FORECAST IS QUITE SIMILAR TO THE LOGISTIC GROWTH EQUATION MODEL...LGEM... VERSION OF SHIPS AND CALLS FOR CAT. 4 INTENSITY WITHING 36 HOURS. IT SHOULD BE NOTED THAT THE PURELY DYNAMICAL MODELS HAVE NOT BEEN VERY BULLISH ON THE STRENGTHENING OF FELIX SO FAR. THE INITIAL MOTION IS JUST A SMIDGEN TO THE RIGHT OF PREVIOUS ESTIMATES...AROUND 285/16. THERE IS NO IMPORTANT CHANGE TO THE TRACK FORECAST REASONING FOR THE NEXT 2-3 DAYS. GLOBAL MODEL PREDICTIONS SHOW A DEEP LAYER RIDGE PERSISTING TO THE NORTH OF FELIX...WHICH SHOULD PREVENT A SIGNIFICANT NORTHWARD SHIFT OF THE HURRICANE'S TRACK OVER THE CARIBBEAN. THERE IS MORE UNCERTAINTY IN THE 4 AND 5 DAY FORECAST LOCATIONS. THE GFS SHOWS A 500 MB TROUGH OVER THE CENTRAL U.S. IN ABOUT 5 DAYS. THIS FEATURE COULD ERODE THE HIGH OVER THE GULF OF MEXICO AND RESULT IN A MORE NORTHWARD TRACK NEAR THE END OF THE FORECAST PERIOD. FOR THIS ADVISORY PACKAGE ONLY A SLIGHT NORTHWARD ADJUSTMENT IS MADE TO THE 96- AND 120-HOUR FORECASTS. THE CURRENT NHC TRACK FORECAST IS ALSO A LITTLE SLOWER THAN THE PREVIOUS ONE AT 3-5 DAYS. IN ANY EVENT IT SHOULD BE RECALLED THAT THE AVERAGE TRACK ERRORS AT 4 AND 5 DAYS RANGE FROM OVER 200 MILES TO NEARLY 300 MILES RESPECTIVELY...SO ONE SHOULD NOT BE FOCUSING ON THE EXACT TRACK AT THESE EXTENDED RANGES. THE RADII OF 12-FT SEAS OVER THE NORTHERN SEMICIRCLE HAVE BEEN EXPANDED BASED ON DATA FROM NOAA DATA BUOY 42059. FORECAST POSITIONS AND MAX WINDS INITIAL 02/1500Z 13.2N 70.1W 90 KT 12HR VT 03/0000Z 13.7N 72.8W 100 KT 24HR VT 03/1200Z 14.4N 76.3W 110 KT 36HR VT 04/0000Z 15.1N 79.5W 120 KT 48HR VT 04/1200Z 15.8N 82.7W 125 KT 72HR VT 05/1200Z 17.0N 87.0W 120 KT 96HR VT 06/1200Z 19.0N 90.5W 70 KT...INLAND 120HR VT 07/1200Z 21.0N 94.0W 85 KT $$ FORECASTER PASCH