WTPA43 PHFO 031422 TCDCP3 HURRICANE IGNACIO DISCUSSION NUMBER 39 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015 500 AM HST THU SEP 03 2015 THE IGNACIO EYE FEATURE FILLED IN BETWEEN 0600 UTC AND 1200 UTC...MORPHING INTO A LONG CONVECTIVE BANDING FEATURE WITH A SMALL CDO. HOWEVER...SINCE 1200 UTC A RAGGED EYE HAS REAPPEARED. OUTFLOW REMAINS HINDERED TO THE NORTHWEST AND SOUTHEAST. OBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES RANGED FROM 3.5...55 KT...FROM SAB TO 4.0...65 KT...FROM PHFO AND JTWC. UW-CIMSS ADT INTENSITY DECREASED TO 53 KT FROM SIX HOURS AGO. HOWEVER...GIVEN THE REDEVELOPED EYE FEATURE...WE WILL MAINTAIN AN INITIAL INTENSITY OF 65 KT FOR THIS ADVISORY. THE INITIAL MOTION IS 305/11 KT AS IGNACIO CONTINUES TO MOVE NORTHWEST INTO A WEAKNESS IN THE RIDGE TO ITS NORTH. TRACK GUIDANCE REMAINS TIGHTLY CLUSTERED THROUGH 72 HOURS...SPREADING A BIT AFTERWARDS BUT DEPICTING A RECURVING PATH THROUGH THE FIVE DAY FORECAST PERIOD. WE WOULD NORMALLY BUILD THE FORECAST TRACK EXCLUSIVELY IN-HOUSE USING THIS GUIDANCE. HOWEVER...SINCE IGNACIO WILL LIKELY BE EXTRATROPICAL ON DAYS FOUR AND FIVE...AND POSSIBLY AS EARLY AS DAY THREE...THE OCEAN PREDICTION CENTER...OPC...WAS CONSULTED FOR FORECAST POSITIONS ON THOSE DAYS. THE 72...96 AND 120 HOUR POSITIONS FOLLOW THE UKMET SOLUTION AS PER OPC. THE FINAL FORECAST TRACK WAS BUMPED TO THE LEFT OF THE PREVIOUS TRACK...AND SLIGHTLY LEFT OF THE TIGHT GUIDANCE ENVELOPE...FROM 24 THROUGH 48 HOURS TO FIT THE SHORT TERM TRACK SMOOTHLY INTO THE LONG RANGE OPC TRACK. LIKE LAST TIME...LITTLE CHANGE IN STRENGTH IS FORECAST THROUGH 24 HOURS AS IGNACIO MOVES NORTHWESTWARD ACROSS ANOMALOUSLY WARM WATER WITHIN AN ENVIRONMENT CONTAINING LESS THAN 20 KT OF SHEAR. SSTS BEGIN TO DROP RAPIDLY ALONG THE FORECAST TRACK AFTER 36 HOURS...SO WE WILL KEEP GRADUAL WEAKENING IN THE FORECAST FROM THAT POINT ONWARDS. IGNACIO WILL LIKELY BEGIN EXTRATROPICAL TRANSITION AT 72 HOURS...OVER 20 DEGREE CELSIUS WATER...THEN BECOME COMPLETELY EXTRATROPICAL AT 96 AND 120 HOURS. THE 45 KT INTENSITY AT 96 AND 120 HOURS WAS COORDINATED WITH OPC. OPC ALSO PROVIDED 34 KT AND 50 KT WIND RADII AT 72 HOURS. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 28.8N 161.7W 65 KT 75 MPH 12H 04/0000Z 29.9N 163.0W 65 KT 75 MPH 24H 04/1200Z 32.0N 164.3W 65 KT 75 MPH 36H 05/0000Z 34.6N 165.0W 60 KT 70 MPH 48H 05/1200Z 37.2N 165.4W 55 KT 65 MPH 72H 06/1200Z 42.5N 164.5W 50 KT 60 MPH...BECOMING EXTRATROPICAL 96H 07/1200Z 47.3N 158.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 08/1200Z 53.0N 143.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER POWELL