WTPN31 PGTW 201500    
1. TYPHOON 26W (SHANSHAN) WARNING NR 013    
   01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   201200Z5 --- NEAR 20.9N1 167.2E6
     MOVEMENT PAST SIX HOURS - 305 DEGREES AT 10 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON EYE FIXED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
   RADIUS OF 100 KT WINDS - 015 NM 
   RADIUS OF 050 KT WINDS - 030 NM 
   RADIUS OF 035 KT WINDS - 150 NM NORTHEAST SEMICIRCLE  
                            130 NM ELSEWHERE
   REPEAT POSIT: 20.9N1 167.2E6
    ---
   FORECASTS:
   12 HRS, VALID AT:
   210000Z3 --- 21.9N2 166.1E4
   MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
   RADIUS OF 100 KT WINDS - 015 NM 
   RADIUS OF 050 KT WINDS - 045 NM NORTHEAST SEMICIRCLE  
                            045 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 160 NM NORTHEAST SEMICIRCLE  
                            140 NM ELSEWHERE
   VECTOR TO 24 HR POSIT: 330 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   211200Z6 --- 23.2N7 165.3E5
   MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT
   RADIUS OF 100 KT WINDS - 025 NM 
   RADIUS OF 050 KT WINDS - 050 NM NORTHEAST SEMICIRCLE  
                            045 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 170 NM NORTHEAST SEMICIRCLE  
                            150 NM ELSEWHERE
   VECTOR TO 36 HR POSIT: 335 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   220000Z4 --- 24.5N1 164.6E7
   MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT
   RADIUS OF 100 KT WINDS - 025 NM 
   RADIUS OF 050 KT WINDS - 050 NM NORTHEAST SEMICIRCLE  
                            045 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 170 NM NORTHEAST SEMICIRCLE  
                            150 NM ELSEWHERE
   VECTOR TO 48 HR POSIT: 350 DEG/ 08 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   221200Z7 --- 26.0N8 164.3E4
   MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
   RADIUS OF 100 KT WINDS - 025 NM 
   RADIUS OF 050 KT WINDS - 045 NM NORTHEAST SEMICIRCLE  
                            045 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 165 NM EAST SEMICIRCLE       
                            145 NM ELSEWHERE
   VECTOR TO 72 HR POSIT: 360 DEG/ 07 KTS
    ---
   72 HRS, VALID AT:
   231200Z8 --- 28.8N8 164.4E5
   MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
   RADIUS OF 100 KT WINDS - 020 NM 
   RADIUS OF 050 KT WINDS - 040 NM NORTHEAST SEMICIRCLE  
                            040 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 160 NM EAST SEMICIRCLE       
                            140 NM ELSEWHERE
    ---
REMARKS:
201500Z8 POSITION NEAR 21.2N5 166.9E2.
TYPHOON (TY) 26W (SHANSHAN), LOCATED APPROXIMATELY 95 NM
NORTH-NORTHEAST OF WAKE ISLAND, HAS TRACKED NORTHWESTWARD AT 10 
KNOTS DURING THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 
201130Z7 INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED 
ON SATELLITE CURRENT INTENSITY ESTIMATES OF 115 KNOTS. ANIMATED 
SATELLITE IMAGERY SHOWS THE SYSTEM HAS INTENSIFIED SLIGHTLY AND HAS 
A 10 NM EYE. ANIMATED WATER VAPOR IMAGERY DEPICTS GOOD OUTFLOW ALOFT 
WITH A MID-LEVEL RIDGE BUILDING IN NORTHEAST OF THE SYSTEM. UW-CIMSS
ANALYSIS INDICATES WEAK VERTICAL WIND SHEAR OVER THE SYSTEM. TY 26W 
IS FORECAST TO TRACK NORTHWESTWARD OVER THE NEXT 12 HOURS UNDER THE
STEERING INFLUENCE OF THE MID-LEVEL RIDGE TO THE NORTHEAST.
AFTERWARDS, THE SYSTEM WILL TRACK INCREASINGLY NORTH-NORTHWESTWARD 
AND THEN NORTHWARD AS AN APPROACHING MID-LATITUDE TROUGH CREATES A
WEAKNESS IN THE SUBTROPICAL RIDGE. TY 26W IS FORECAST TO INTENSIFY
THROUGH THE 36 HOUR PERIOD WITHIN A FAVORABLE UPPER LEVEL 
ENVIRONMENT. AFTER THAT, INCREASED WIND SHEAR ASSOCIATED WITH THE 
APPROACHING MID-LATITUDE TROUGH WILL BEGIN TO WEAKEN THE SYSTEM.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 201200Z5 IS 22 FEET. REFER TO
WWPW31 RJTX FOR ADDITIONAL SEA HEIGHT INFORMATION. NEXT WARNINGS AT
202100Z5 (DTG 201951Z8), 210300Z6 (DTG 210151Z0), 210900Z2 (DTG
210751Z6) AND 211500Z9 (DTG 211351Z3).//