000 WTPZ44 KNHC 222032 TCDEP4 HURRICANE HILARY DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092011 200 PM PDT THU SEP 22 2011 HILARY HAS STRENGTHENED RAPIDLY THROUGHOUT THE DAY. THE EYE FIRST APPEARED IN SATELLITE IMAGES AROUND 1500 UTC...AND IT HAS MORE DISTINCT SINCE THAT TIME. CLOUD TOPS ARE AS COLD AS -80C TO THE NORTH OF THE EYE...AND THE OVERALL CONVECTIVE PATTERN HAS BECOME MORE SYMMETRIC DURING THE PAST FEW HOURS. DVORAK CLASSIFICATIONS HAVE INCREASED AND NOW SUPPORT AN INITIAL WIND SPEED OF 90 KT...AND THAT COULD BE CONSERVATIVE. HILARY WILL LIKELY STRENGTHEN FURTHER DURING THE NEXT 24 HOURS OR SO AS IT REMAINS IN A CONDUCIVE ENVIRONMENT. BY THE END OF THE FORECAST PERIOD...VERTICAL WIND SHEAR COULD INCREASE OVER THE HURRICANE AS IT MOVES INTO A LESS FAVORABLE THERMODYNAMIC ENVIRONMENT. THE OFFICIAL FORECAST CLOSELY FOLLOWS THE SHIPS...LGEM...AND FLORIDA STATE SUPERENSEMBLE MODELS AND IS HIGHER THAN THE PREVIOUS FORECAST. HILARY HAS WOBBLED A LITTLE TO THE NORTH OF THE PREVIOUS TRACK...AND THE LATEST INITIAL MOTION ESTIMATE IS 300/9. MID-LEVEL RIDGING IS EXPECTED TO STRENGTHEN TO THE NORTH OF THE HURRICANE DURING THE NEXT FEW DAYS. THIS PATTERN SHOULD STEER HILARY WEST-NORTHWESTWARD DURING THAT TIME. BY THE END OF THE PERIOD...THERE IS A SIGNIFICANT SPREAD IN THE MODELS WITH THE REGIONAL HURRICANE MODELS SHOWING A SHARP NORTHWARD TURN WHILE MOST OF THE GLOBAL MODELS KEEP HILARY ON A MORE STRAIGHT WESTWARD PATH. OVERALL...THE OFFICIAL FORECAST HAS BEEN NUDGED TO THE SOUTH LATE IN THE FORECAST PERIOD...LEANING TOWARD THE GLOBAL MODELS. AN ASCAT OVERPASS AT 1644 UTC INDICATE THAT THE WIND RADII REMAIN QUITE SMALL. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 15.6N 99.8W 90 KT 105 MPH 12H 23/0600Z 16.1N 101.1W 110 KT 125 MPH 24H 23/1800Z 16.5N 102.8W 115 KT 135 MPH 36H 24/0600Z 16.8N 104.5W 115 KT 135 MPH 48H 24/1800Z 17.1N 106.2W 110 KT 125 MPH 72H 25/1800Z 18.0N 109.4W 105 KT 120 MPH 96H 26/1800Z 19.0N 112.0W 95 KT 110 MPH 120H 27/1800Z 19.5N 113.5W 85 KT 100 MPH $$ FORECASTER CANGIALOSI/PASCH