000 WTPZ43 KNHC 062032 TCDEP3 HURRICANE FELICIA DISCUSSION NUMBER 13 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082009 200 PM PDT THU AUG 06 2009 VISIBLE SATELLITE IMAGES SHOW A CLASSIC MAJOR HURRICANE WITH AN EYE OF ABOUT 20 NM IN DIAMETER AND APPARENT MESOVORTICES ROTATING AROUND THE CENTER. CLOUD TOPS HAVE WARMED A LITTLE BIT IN THE EYEWALL...AND OBJECTIVE T-NUMBERS HAVE COME DOWN SLIGHTLY FROM THIS MORNING. THE INITIAL INTENSITY WILL BE REDUCED TO 115 KT IN GOOD AGREEMENT WITH RECENT DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB. A CONTINUED SLOW WEAKENING OF THE HURRICANE IS LIKELY DUE TO PROGRESSIVELY COOLER WATERS IN ITS PATH. THIS DECREASE IN STRENGTH IS EXPECTED TO BE TEMPERED BY FELICIA HAVING SOME ANNULAR HURRICANE CHARACTERISTICS. THIS ANNULAR STRUCTURE IN COMBINATION WITH LOW WIND SHEAR FOR THE NEXT COUPLE OF DAYS COULD ENABLE THE SYSTEM TO MAINTAIN ITS INTENSITY MORE THAN IT NORMALLY WOULD OVER MARGINAL SSTS. THE OFFICIAL FORECAST WILL REMAIN ON THE HIGHER SIDE OF THE GUIDANCE DURING THE FIRST 36 HOURS...AND IS NOT TOO DISSIMILAR TO THE HWRF MODEL. AT ABOUT THE TIME THAT FELICIA MOVES INTO THE CENTRAL PACIFIC...GLOBAL MODELS INCREASE THE WIND SHEAR SIGNIFICANTLY...WHICH SHOULD CONTINUE THE WEAKENING PROCESS EVEN THOUGH WATER TEMPERATURES GRADUALLY WARM WEST OF 140W. IN FACT... ALL OF THE RELIABLE INTENSITY GUIDANCE SHOW THE SYSTEM TO BE EITHER A TROPICAL DEPRESSION OR DISSIPATED AT THE END OF THE PERIOD. THE OFFICIAL FORECAST WILL KEEP FELICIA AS A TROPICAL CYCLONE THROUGH THE NEXT FIVE DAYS...THOUGH THE STRONG SHEAR COULD EVEN WEAKEN THE SYSTEM TO A REMNANT LOW BY DAY 5. THE HURRICANE REMAINS ON TRACK AND CONTINUES TO MOVE AT ABOUT 305/9. THERE HAS BEEN NO CHANGE IN SYNOPTIC REASONING WITH THE GLOBAL MODELS SUGGESTING THAT FELICIA WILL TURN MORE TO WEST-NORTHWEST THEN WEST WITH TIME AS RIDGING BUILDS NORTHEAST OF HAWAII. GLOBAL MODELS ARE TIGHTLY CLUSTERED THROUGHOUT 72 HOURS...AND LITTLE CHANGE WAS MADE TO THE NHC FORECAST. THEREAFTER...SINCE FELICIA IS FORECAST TO BE MUCH WEAKER AT LONG-RANGE...THE OFFICIAL FORECAST WILL ASSUME THAT THE THE SYSTEM WILL BE STEERED A LITTLE SOUTH OF DUE WEST IN THE LOW-LEVEL TRADES. HOWEVER...IT IS IMPORTANT NOT TO FOCUS ON THE EXACT FORECAST POINTS AT DAYS 4 AND 5 BECAUSE THERE IS CONSIDERABLE UNCERTAINTY AT THAT TIME FRAME. AS A NOTE...FELICIA IS THE STRONGEST HURRICANE IN THE EASTERN PACIFIC SINCE HURRICANE DANIEL OF 2006. FORECAST POSITIONS AND MAX WINDS INITIAL 06/2100Z 16.4N 132.7W 115 KT 12HR VT 07/0600Z 17.2N 133.9W 105 KT 24HR VT 07/1800Z 18.3N 135.5W 95 KT 36HR VT 08/0600Z 19.2N 137.7W 80 KT 48HR VT 08/1800Z 19.7N 140.2W 70 KT 72HR VT 09/1800Z 20.0N 146.0W 50 KT 96HR VT 10/1800Z 19.7N 151.5W 35 KT 120HR VT 11/1800Z 19.5N 156.5W 30 KT $$ FORECASTER BLAKE