000 WTPZ44 KNHC 230850 TCDEP4 HURRICANE CELIA DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010 200 AM PDT WED JUN 23 2010 THE CLOUD PATTERN ASSOCIATED WITH CELIA HAS CHANGED LITTLE SINCE THE PREVIOUS ADVISORY. MICROWAVE IMAGERY OVER THE PAST 6-9 HOURS CONTINUES TO DEPICT A TILTED SYSTEM WITH THE LOW-LEVEL CENTER DISPLACED TO THE EAST OF THE MID-LEVEL CENTER. THE MICROWAVE IMAGES ALSO INDICATE THAT THE EYE HAS BECOME OPEN OVER THE NORTHEAST QUADRANT. BASED ON THESE TRENDS AND SLIGHTLY LOWER DVORAK CURRENT INTENSITY NUMBERS...THE INITIAL INTENSITY IS LOWERED TO 75 KT. AS HAS BEEN THE CASE OVER THE PAST COUPLE OF DAYS...THE GLOBAL MODELS SUGGEST THAT THE UPPER-LEVEL EASTERLIES SHOULD RELAX DURING THE NEXT 24 HOURS. IN TURN...THE SHIPS GUIDANCE INDICATES THAT THE SHEAR SHOULD DECREASE TO LESS THAN 10 KT LATER TODAY...AND REMAIN VERY LOW THROUGHOUT THE ENTIRE FORECAST PERIOD. THEREFORE...AS CELIA REMAINS OVER WARM SSTS DURING THE NEXT COUPLE OF DAYS...I WILL ONCE AGAIN FORECAST STRENGTHENING. THE NEW INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND THE GFDL MODEL...BUT IS A LITTLE ABOVE THE SHIPS/LGEM GUIDANCE. IN ABOUT 3 DAYS...THE HURRICANE IS FORECAST TO BEGIN WEAKENING AS IT MOVES OVER COOLER WATERS. CELIA CONTINUES MOVING WESTWARD TO THE SOUTH A STRONG MID-LEVEL RIDGE. THE RIDGE IS FORECAST TO WEAKEN IN A DAY OR SO...AND CELIA SHOULD TURN WEST-NORTHWESTWARD AS THAT OCCURS. THE TRACK GUIDANCE IS IN REMARKABLY GOOD AGREEMENT...EXCEPT FOR THE ECMWF WHICH WEAKENS THE RIDGE MORE THAN THE OTHER GLOBAL MODELS. THAT RESULTS IN MORE DECELERATION OF THE FORWARD SPEED OF THE HURRICANE THAN PREDICTED BY THE REMAINDER OF THE GUIDANCE. THE NHC FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY THROUGH 72 HOURS...BUT HAS BEEN ADJUSTED A LITTLE WESTWARD THEREAFTER. THE NEW TRACK IS A LITTLE SLOWER THAN THE CONSENSUS AT DAYS 4 AND 5 GIVING SOME CREDENCE TO THE SLOWER ECMWF SOLUTION. FORECAST POSITIONS AND MAX WINDS INITIAL 23/0900Z 11.9N 108.0W 75 KT 12HR VT 23/1800Z 12.0N 109.8W 80 KT 24HR VT 24/0600Z 12.3N 112.2W 85 KT 36HR VT 24/1800Z 12.9N 114.5W 90 KT 48HR VT 25/0600Z 13.6N 116.8W 90 KT 72HR VT 26/0600Z 14.9N 120.8W 70 KT 96HR VT 27/0600Z 15.8N 124.0W 55 KT 120HR VT 28/0600Z 16.0N 126.0W 40 KT $$ FORECASTER BROWN