WTXS31 PGTW 232100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 17P (GILLIAN) WARNING NR 012// RMKS/ 1. TROPICAL CYCLONE 17P (GILLIAN) WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 231800Z --- NEAR 15.4S 103.5E MOVEMENT PAST SIX HOURS - 180 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 010 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 140 KT, GUSTS 170 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT REPEAT POSIT: 15.4S 103.5E --- FORECASTS: 12 HRS, VALID AT: 240600Z --- 16.8S 103.4E MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 175 DEG/ 07 KTS --- 24 HRS, VALID AT: 241800Z --- 18.1S 103.5E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 175 DEG/ 05 KTS --- 36 HRS, VALID AT: 250600Z --- 19.1S 103.6E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 175 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 251800Z --- 20.2S 103.7E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 175 DEG/ 04 KTS --- 72 HRS, VALID AT: 261800Z --- 21.7S 103.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 190 DEG/ 03 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 271800Z --- 22.9S 103.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 230 DEG/ 02 KTS --- 120 HRS, VALID AT: 281800Z --- 23.4S 102.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 232100Z POSITION NEAR 15.7S 103.5E. TROPICAL CYCLONE (TC) 17P (GILLIAN), LOCATED APPROXIMATELY 730 NM WEST-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THAT THE SYSTEM, TYPICAL OF VERY INTENSE CYCLONES WITH CENTRAL WIND SPEEDS IN EXCESS OF 120 KNOTS, HAS UNDERGONE AN EYEWALL REPLACEMENT AS THE GEOMETRIC EYE CONTRACTED DOWN TO 12 NM IN DIAMETER. THIS IS READILY APPARENT ON A 231756Z 85GHZ TRMM MICROWAVE IMAGE. HOWEVER, THE EIR LOOP ALSO SHOWS THAT CONVECTION ALONG THE SOUTHEASTERN QUADRANT HAS BEGUN TO ELONGATE AND SUBSIDENCE ALONG THE WESTERN FLANK - AS EVIDENCED BY THE SHARP OUTLINE - HAS COMMENCED. THIS IS AN INDICATION THAT THE CYCLONE HAS PEAKED INTENSITY AS THE MID-LATITUDE TROUGH DIGGING IN FROM THE SOUTHWEST HAS BEGUN TO IMPACT THE SYSTEM. THE INITIAL POSITION AND INTENSITY ARE BASED ON CONGRUENT AND COLLOCATED DVORAK FIXES FROM PGTW AND KNES WITH HIGH CONFIDENCE. UPPER LEVEL ANALYSIS INDICATES TC 17P HAS MOVED FURTHER AWAY FROM THE RIDGE AXIS INTO A MODERATE (15-20 KNOT) VERTICAL WIND SHEAR (VWS) AREA. HOWEVER, A STRONG SOUTHEASTWARD OUTFLOW CHANNEL IS SUSTAINING THE SUPER DEEP CONVECTION. THE CYCLONE IS EXPECTED TO CONTINUE TRACKING SOUTHWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE EAST. AS THE AFOREMENTIONED MID-LATITUDE TROUGH WEAKENS THE STR, THE SYSTEM WILL BEGIN TO SLOW DOWN AND POSSIBLY EVEN TRACK ON A SOUTH-SOUTHEASTWARD TRAJECTORY. AFTER TAU 72, A SECONDARY STR TRAILING THE TROUGH WILL ASSUME STEERING AND DRIVE A GREATLY-WEAKENED TC 17P WESTWARD. TC GILLIAN IS EXPECTED TO GRADUALLY WEAKEN AS VWS INCREASES CONCURRENT TO ITS POLEWARD TRACK. NEAR TAU 72. THE SYSTEM WILL RAPIDLY DECAY AS VWS SIGNIFICANTLY AMPLIFIES (OVER 50 KNOTS), IN PART DUE THE STORM MOTION TURNING AGAINST THE UPPER LEVEL WIND FLOW. THE MODEL TRACK CONSENSUS HAS SWUNG TO A MORE EASTWARD TRAJECTORY OVER THE PAST 4 RUNS AS MORE MEMBERS HAVE ADJUSTED TO A STRONGER MID-LATITUDE TROUGH. GFDN AND JGSM RETAIN AN EARLY WESTWARD TRACK AND ARE NOW THE OUTLIERS. THE CURRENT JTWC TRACK FORECAST IS NOTICEABLY MORE EASTWARD OF THE PREVIOUS FORECAST BUT THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY; IT IS LAID JUST TO THE EAST OF THE MODEL CONSENSUS WITH FAIR CONFIDENCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z IS 35 FEET. NEXT WARNINGS AT 240900Z AND 242100Z. // NNNN