WTPS31 PGTW 061500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 18P (DONNA) WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 061200Z --- NEAR 13.5S 164.1E MOVEMENT PAST SIX HOURS - 205 DEGREES AT 02 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 190 NM SOUTHWEST QUADRANT 145 NM NORTHWEST QUADRANT REPEAT POSIT: 13.5S 164.1E --- FORECASTS: 12 HRS, VALID AT: 070000Z --- 14.2S 163.9E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 180 DEG/ 06 KTS --- 24 HRS, VALID AT: 071200Z --- 15.4S 163.9E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 095 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 07 KTS --- 36 HRS, VALID AT: 080000Z --- 16.8S 164.2E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 185 NM NORTHEAST QUADRANT 200 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 160 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 081200Z --- 18.2S 164.7E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 095 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 08 KTS --- 72 HRS, VALID AT: 091200Z --- 20.9S 166.6E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 135 DEG/ 12 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 101200Z --- 24.1S 170.2E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 130 DEG/ 15 KTS --- 120 HRS, VALID AT: 111200Z --- 27.7S 175.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 250 NM NORTHEAST QUADRANT 245 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT --- REMARKS: 061500Z POSITION NEAR 13.7S 164.0E. TROPICAL CYCLONE (TC) 18P (DONNA), LOCATED APPROXIMATELY 350 NM NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED SOUTH-SOUTHWESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A RAGGED 12-NM EYE WITH IMPROVED CONVECTIVE STRUCTURE. HOWEVER, THE MOST RECENT EIR IMAGERY INDICATES THAT THE EYE HAS FILLED. A 061113Z METOP-A 89 GHZ IMAGE SHOWS THE BULK OF DEEP CONVECTION IS CONFINED TO THE NORTHERN SEMI-CIRCLE WITH AN ASYMMETRIC MICROWAVE EYE FEATURE POSITIONED ALONG THE SOUTHERN EDGE OF THIS DEEP CONVECTION. BASED ON THE EYE AND RECENT MICROWAVE IMAGERY, THERE IS GOOD CONFIDENCE IN THE CURRENT POSITION. TRACK MOTION REMAINS SLOW WITH A SLIGHT SOUTHWARD DRIFT. THE CURRENT INTENSITY IS ASSESSED AT 90 KNOTS BASED ON DVORAK ESTIMATES OF T5.0 FROM PGTW, PHFO AND KNES. TC 18P IS CURRENTLY LOCATED WITHIN A COMPETING STEERING ENVIRONMENT BETWEEN A WEAK SUBTROPICAL RIDGE (STR) OVER NORTHEAST AUSTRALIA AND A STRONG STR TO THE EAST. THE WESTERN STR IS FORECAST TO WEAKEN SIGNIFICANTLY AS A DEEP MIDLATITUDE TROUGH DEEPENS ACROSS THE CORAL SEA, WHICH WILL ALLOW THE EASTERN STR TO BECOME THE DOMINANT STEERING INFLUENCE WITHIN THE NEXT 24 TO 36 HOURS. TC DONNA IS FORECAST TO INTENSIFY TO A PEAK OF 110 KNOTS UNDER FAVORABLE CONDITIONS TO INCLUDE WARM SST, LOW VERTICAL WIND SHEAR (VWS) AND ROBUST POLEWARD OUTFLOW. AFTER TAU 36, TC 18P SHOULD BEGIN TO ACCELERATE SOUTHWARD AS IT TRACKS ALONG THE WESTERN PERIPHERY OF THE STR. GRADUAL WEAKENING SHOULD OCCUR AS THE SYSTEM TRACKS OVER COOLER SST. NEAR TAU 72, TC 18P WILL BEGIN EXTRA-TROPICAL TRANSITION AS IT INTERACTS WITH THE MIDLATITUDE WESTERLIES AND A WEAK BAROCLINIC ZONE. THE SYSTEM WILL ACCELERATE SOUTHEASTWARD AFTER TAU 72 AS IT COMPLETES EXTRA-TROPICAL TRANSITION AND BECOMES EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES. DYNAMIC MODEL GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. DURING THE EXTENDED PERIOD, TC 18P WILL WEAKEN RAPIDLY DUE TO INCREASING VWS AND COOL SST LESS THAN 25C. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 061200Z IS 30 FEET. NEXT WARNINGS AT 062100Z, 070300Z, 070900Z AND 071500Z.//