WTPS33 PGTW 280300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 21P (SERU) WARNING NR 008// RMKS/ 1. TROPICAL CYCLONE 21P (SERU) WARNING NR 008 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 280000Z --- NEAR 23.0S 172.5E MOVEMENT PAST SIX HOURS - 090 DEGREES AT 02 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 SUBTROPICAL RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT REPEAT POSIT: 23.0S 172.5E --- FORECASTS: 12 HRS, VALID AT: 281200Z --- 23.1S 173.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 090 DEG/ 03 KTS --- 24 HRS, VALID AT: 010000Z --- 23.1S 173.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL --- REMARKS: 280300Z POSITION NEAR 23.0S 172.7E. 28FEB25. TROPICAL CYCLONE 21P (SERU), LOCATED APPROXIMATELY 359 NM EAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED EASTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. SATELLITE ANALYSIS REVEALED A DECOUPLING HAS OCCURRED DUE TO INCREASINGLY HOSTILE VERTICAL WIND SHEAR (VWS) AND HAS RESULTED IN A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE WIND FIELD REMAINS STRONG DUE TO AN ENHANCED PRESSURE GRADIENT BUT IS EXPECTED TO CONTINUE WEAKENING AS THE VORTEX STRUCTURE TILTS BEYOND REPAIR. THE MAJORITY OF THE MOISTURE FIELD IS DISPLACED ASYMMETRICALLY EAST AND POLEWARD OF CENTER, FURTHER SUPPORTING THE CLASSIFICATION OF THIS HYBRID SYSTEM AS NOW FULLY SUBTROPICAL. ADDITIONALLY, THE VORTICITY SIGNATURE IS ASSESSED AS FRONTAL. THIS SYSTEM IS EXPECTED TO BECOME INCREASINGLY ELONGATED WITH ASSOCIATED WINDS DECREASING. MODEL GUIDANCE INDICATES IT WILL EVENTUALLY FILL AND BECOME ABSORBED INTO THE EXISTING SPCZ BOUNDARY TO WHICH IT REMAINS AFFIXED. 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. MINIMUM CENTRAL PRESSURE AT 280000Z IS 996 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280000Z IS 18 FEET. REFER TO TROPICAL CYCLONE 18P (ALFRED) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES.// NNNN