WTPS31 PGTW 060900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 25P (HAROLD) WARNING NR 015// RMKS/ 1. TROPICAL CYCLONE 25P (HAROLD) WARNING NR 015 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 15.8S 167.8E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 11 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 135 KT, GUSTS 165 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT REPEAT POSIT: 15.8S 167.8E --- FORECASTS: 12 HRS, VALID AT: 061800Z --- 16.4S 169.8E MAX SUSTAINED WINDS - 130 KT, GUSTS 160 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 110 DEG/ 13 KTS --- 24 HRS, VALID AT: 070600Z --- 17.3S 172.4E MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 115 DEG/ 16 KTS --- 36 HRS, VALID AT: 071800Z --- 18.6S 175.5E MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 115 DEG/ 18 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 080600Z --- 20.0S 179.0E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 115 DEG/ 11 KTS --- 72 HRS, VALID AT: 090600Z --- 21.7S 176.8W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING SUBTROPICAL RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 120 DEG/ 42 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 100600Z --- 29.2S 159.9W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT --- REMARKS: 060900Z POSITION NEAR 15.9S 168.3E. 06APR20. TROPICAL CYCLONE 25P (HAROLD), LOCATED APPROXIMATELY 118 NM NORTH-NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED EAST- SOUTHEASTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS TC 25P HAS MAINTAINED A WELL DEFINED 15NM EYE WITH SYMMETRIC DEEP CONVECTION THROUGHOUT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE AND A MICROWAVE EYE SEEN IN THE 060554Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY IS BASED ON THE DVORAK ESTIMATE OF T7.0 (140 KNOTS) FROM PGTW AND A 060610Z ADVANCED DVORAK TECHNIQUE ESTIMATE OF 127 KNOTS. ENVIRONMENTAL ANALYSIS INDICATES A VERY FAVORABLE ENVIRONMENT WITH LOW (10-15 KNOT) VERTICAL WIND SHEAR (VWS), STRONG POLEWARD OUTFLOW, AND HOT (29-30 DEGREES CELSIUS) SEA SURFACE TEMPERATURES (SST). TC 25P HAS BEGUN TO TRACK MORE POLEWARD AS THE SUBTROPICAL RIDGE TO THE NORTHEAST HAS ASSUMED STEERING. THE STRONG POLEWARD OUTFLOW AND WARM SST, WILL GRADUALLY BE TEMPERED BY INCREASING VWS AFTER TAU 48 WHICH WILL WEAKEN THE CYCLONE DOWN TO 60KTS BY TAU 96. BY TAU 72, TC HAROLD WILL BEGIN SUBTROPICAL TRANSITION AS TRACK SPEED RAPIDLY INCERASES, BECOMING SUBTROPICAL BY TAU 96. INTENSITY GUIDANCE IS IN FAIR AGREEMENT OVER THE NEXT 48 HOURS, BECOMING MORE CONCLUSIVE AS VWS BECOMES MORE PREDOMINATE. NUMERICAL TRACK GUIDANCE MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 060600Z IS 45 FEET. NEXT WARNINGS AT 061500Z, 062100Z, 070300Z AND 070900Z.// NNNN