Typhoon Koguma

WTPN33 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL STORM 27W (KOGUMA) WARNING NR 036//
RMKS/
1. TROPICAL STORM 27W (KOGUMA) WARNING NR 036    
   02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   131800Z --- NEAR 38.3N 157.2E
     MOVEMENT PAST SIX HOURS - 045 DEGREES AT 20 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
                            160 NM SOUTHEAST QUADRANT
                            100 NM SOUTHWEST QUADRANT
                            095 NM NORTHWEST QUADRANT
   REPEAT POSIT: 38.3N 157.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   140600Z --- 40.6N 160.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT
                            190 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            100 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 065 DEG/ 18 KTS
    ---
   24 HRS, VALID AT:
   141800Z --- 42.0N 165.3E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 220 NM NORTHEAST QUADRANT
                            195 NM SOUTHEAST QUADRANT
                            180 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
    ---
REMARKS:
132100Z POSITION NEAR 38.9N 158.1E.
13OCT26. TROPICAL STORM 27W (KOGUMA), LOCATED APPROXIMATELY 752
NM EAST OF MISAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 20 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED IMAGERY (EIR)
SHOWS 27W WITH AN INCREASINGLY ASYMMETRICAL STRUCTURE AND LOSS OF
CENTRAL CONVECTION. FURTHER ANALYSIS REVEALS 27W HAS LOST TROPICAL
CHARACTERISTICS WITH AN ASYMMETRICAL WIND FIELD AND CONVECTIVE
STRUCTURE AS WELL AS EXPANDING RADIUS OF MAXIMUM WINDS (RMW).
ADDITIONALLY, THE SYSTEM IS CURRENTLY WITHIN LESS THAN 24 C SEA
SURFACE TEMPERATURES AND 30-40 KTS OF VERTICAL WIND SHEAR WHICH
CONTINUES TO ENTRAIN DRY AIR INTO THE CORE. THE SYSTEM IS ASSESSED
TO HAVE BEGUN SUBTROPICAL TRANSITION (STT) AND IS EXPECTED TO
COMPLETE WITHIN 12 HOURS, WITH LIKELY SUBSEQUENT EXTRATROPICAL
TRANSITION (ETT) AS THE SYSTEM NEARS THE UPPER LEVEL JET AND
STRONGER BAROCLINIC ZONE. THE SYSTEM IS EXPECTED TO STEADILY WEAKEN
AS IT TRANSITIONS DUE TO THE HOSTILE ENVIRONMENTAL CONDITIONS. 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 131800Z IS 988MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 131800Z IS 24 FEET. REFER TO TROPICAL
DEPRESSION 28W (TWENTYEIGHT) WARNINGS (WTPN31 PGTW) FOR SIX-HOURLY
UPDATES.
//
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