WTPS32 PGTW 060900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 17P (IRIS) WARNING NR 029 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 060600Z --- NEAR 19.4S 153.8E MOVEMENT PAST SIX HOURS - 045 DEGREES AT 01 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT REPEAT POSIT: 19.4S 153.8E --- FORECASTS: 12 HRS, VALID AT: 061800Z --- 18.7S 153.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 330 DEG/ 05 KTS --- 24 HRS, VALID AT: 070600Z --- 17.9S 152.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 345 DEG/ 05 KTS --- 36 HRS, VALID AT: 071800Z --- 16.9S 152.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 345 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 080600Z --- 15.8S 152.3E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 005 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 345 DEG/ 06 KTS --- 72 HRS, VALID AT: 090600Z --- 13.6S 151.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 060900Z POSITION NEAR 19.2S 153.7E. TROPICAL CYCLONE (TC) 17P (IRIS), LOCATED APPROXIMATELY 480 NM EAST- SOUTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED NORTHEASTWARD AT 01 KNOT OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH THE REMAINING CONVECTION SHEARED 150NM TO THE SOUTHEAST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 060540Z HIMAWARI VISIBLE SATELLITE IMAGE WHICH SHOWS THE LLCC. THE INITIAL INTENSITY OF 40 KNOTS IS BASED ON A 060525Z SATCON ESTIMATE OF 40 KNOTS. THIS IS HEDGED SLIGHTLY ABOVE A PGTW DVORAK CURRENT INTENSITY (CI) ESTIMATE OF T2.5 (35 KNOTS) WHICH IS UNDERESTIMATING WIND SPEEDS DUE TO THE LACK OF CONVECTION. ENVIRONMENTAL ANALYSIS SHOWS MODERATE (20 TO 25 KNOT) VERTICAL WIND SHEAR WHICH IS OFFSET BY EXCELLENT POLEWARD OUTFLOW. SEA SURFACE TEMPERATURES REMAIN FAVORABLE, NEAR 29 DEGREES CELSIUS. DYNAMIC MODEL GUIDANCE CONTINUES TO COME INTO BETTER AGREEMENT INDICATING A NORTHWARD TRACK. AS TC 17P TRACKS NORTHWARD IT WILL MOVE INTO A MORE FAVORABLE WIND SHEAR ENVIRONMENT WHICH WILL HELP TO MAINTAIN AN INTENSITY OF 40 KNOTS THROUGH TAU 24. MOST OF THE MODEL GUIDANCE IS INDICATING THAT TC 17P WILL DISSIPATE BY TAU 72 BUT NAVGEM CONTINUES TO INDICATE INTENSIFICATION BEYOND TAU 72. THEREFORE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK AND INTENSITY. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 060600Z IS 15 FEET. NEXT WARNINGS AT 061500Z, 062100Z, 070300Z AND 070900Z.//