WTPN31 PGTW 242100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SUBTROPICAL STORM 02W (SURIGAE) WARNING NR 046// RMKS/ 1. SUBTROPICAL STORM 02W (SURIGAE) WARNING NR 046 01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 241800Z --- NEAR 21.7N 134.1E MOVEMENT PAST SIX HOURS - 115 DEGREES AT 12 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 BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 260 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 170 NM NORTHWEST QUADRANT REPEAT POSIT: 21.7N 134.1E --- FORECASTS: 12 HRS, VALID AT: 250600Z --- 22.0N 137.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 230 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 065 DEG/ 23 KTS --- 24 HRS, VALID AT: 251800Z --- 23.7N 142.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 230 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT --- REMARKS: 242100Z POSITION NEAR 21.8N 135.0E. 24APR21. SUBTROPICAL STORM (SS) 02W (SURIGAE), LOCATED APPROXIMATELY 438 NM WEST-SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED EAST- SOUTHEASTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. THE SYSTEM REMAINS ASSESSED AS A SUBTROPICAL STORM BUT IS EXPECTED TO RAPIDLY TRANSITION TO AN EXTRA-TROPICAL LOW WITHIN THE NEXT 12 TO 18 HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY CONTINUES TO DEPICT A HIGHLY ASYMMETRIC, FRONTAL STRUCTURE WITH EXTENSIVE DRY AIR PUNCHING INTO THE WESTERN AND SOUTHERN PERIPHERIES. THE SYSTEM IS LOCATED UNDER A MAJOR UPPER-LEVEL TROUGH WITH STRONG VERTICAL WIND SHEAR AND IS EMBEDDED WITHIN A STRONG BAROCLINIC ZONE AS EVIDENCED BY EXPANSIVE COLD-AIR STRATOCUMULUS IN SATELLITE IMAGERY. THE INITIAL INTENSITY REMAINS ASSESSED AT 40 KNOTS BASED ON RECENT ASCAT DATA AS WELL AS A 240911Z SENTINEL-1B SAR PASS, WHICH INDICATES MAXIMUM WINDS OF 40-48 KNOTS. SS 02W IS FORECAST TO TRACK EASTWARD TO EAST- NORTHEASTWARD WHILE UNDERGOING EXTRA-TROPICAL TRANSITION (ETT). SURIGAE WILL COMPLETE ETT AS A MINOR SHORT-WAVE TROUGH, CURRENTLY LOCATED SOUTH OF KYUSHU, DIGS SOUTHEASTWARD OVER THE NEXT 12 TO 18 HOURS PROVIDING UPPER-LEVEL SUPPORT. THE SYSTEM MAY INTENSIFY SLIGHTLY AS AN EXTRA-TROPICAL LOW TOWARD THE END OF THE FORECAST PERIOD AND WILL REMAIN A LARGE, GALE-FORCE LOW AS IT TRANSITS SOUTH OF JAPAN. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241800Z IS 22 FEET.// NNNN