MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 08W (KHANUN) WARNING NR 013
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
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WARNING POSITION:
181200Z --- NEAR 33.9N 126.2E
MOVEMENT PAST SIX HOURS - 005 DEGREES AT 15 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
REPEAT POSIT: 33.9N 126.2E
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FORECASTS:
12 HRS, VALID AT:
190000Z --- 36.7N 126.8E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 24 HR POSIT: 025 DEG/ 11 KTS
---
24 HRS, VALID AT:
191200Z --- 38.7N 127.9E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 36 HR POSIT: 050 DEG/ 09 KTS
---
36 HRS, VALID AT:
200000Z --- 39.9N 129.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
181500Z POSITION NEAR 34.6N 126.4E.
TROPICAL STORM 08W (KHANUN), LOCATED APPROXIMATELY 30 NM NORTHWEST
OF CHEJU-DO, HAS TRACKED NORTHWARD AT 15 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 181200Z IS 15 FEET.
NEXT WARNINGS AT 182100Z, 190300Z, 190900Z AND 191500Z.//
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WDPN31 PGTW 181500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (KHANUN) WARNING
NR 13//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 08W (KHANUN), LOCATED APPROXIMATELY 30 NM
NORTHWEST OF CHEJU-DO, HAS TRACKED NORTHWARD AT 15 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR)
SHOWS CONVECTION HAS STEADILY DECREASED OVER THE LOW LEVEL
CIRCULATION CENTER (LLCC), PARTIALLY EXPOSING THE LOW LEVEL. THE
DEEPEST CONVECTION REMAINS WITHIN THE SOUTHEASTERN QUADRANT. THE
CURRENT INTENSITY IS BASED ON OBSERVATIONS FROM CHEJU-DO INDICATING
THE STRONGEST WINDS ARE AROUND 40 TO 45 KNOTS AND IS CONSISTENT WITH
THE 2.5/3.0 DVORAK ESTIMATE FROM PGTW. THE CURRENT POSITION IS BASED
ON THE PARTIALLY EXPOSED LLCC IN EIR. THE TRACK HAS SHIFTED EASTWARD
FROM THE PREVIOUS FORECAST AS TRACK SPEEDS HAVE BEEN HIGHER THAN
PREVIOUSLY FORECAST AND THE PRIMARY STEERING INFLUENCE, THE SUB-
TROPICAL RIDGE (STR) LOCATED OVER SOUTHERN JAPAN, HAS NOT BUILT
TOWARDS THE KOREAN PENINSULA AS EXPECTED. MODEL GUIDANCE HAS BEEN
SHIFTING TO A MORE EASTWARD TRACK OVER THE PAST 12 HOURS AND IS IN
KEEPING WITH THE CURRENT FORECAST. DECREASING SEA SURFACE
TEMPERATURES (SSTS) AND INCREASING VERTICAL WIND SHEAR (VWS) HAVE
BEEN SLOWLY WEAKENING TS 08W OVER THE PAST SIX HOURS. THERE IS HIGH
CONFIDENCE IN THE POSITION.
3. FORECAST REASONING.
A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 08W IS EXPECTED TO TRACK POLEWARD ALONG THE STR INTO THE
KOREAN PENINSULA WITHIN THE NEXT 6 TO 12 HOURS. THE OVERALL
ENVIRONMENT WILL REMAIN UNFAVORABLE THROUGH DISSIPATION BY TAU 36.
WITH THE FORECAST TRACK SHIFTING SLIGHTLY TO THE EAST, LAND
INTERACTION IS EXPECTED TO PLAY A GREATER ROLE IN THE DISSIPATION
SCENARIO. SSTS WILL REMAIN IN THE 22 TO 24 CELSIUS RANGE ALONG THE
WESTERN COAST OF KOREA, WITH TEMPERATURES DECREASING TO 19 TO 20
CELSIUS IN THE SEA OF JAPAN. AN UPPER LEVEL LOW LOCATED OVER
NORTHEASTERN CHINA WILL CAUSE VWS TO INCREASE AS TS 08W MOVES
FURTHER NORTH. MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE CURRENT
FORECAST THROUGH TAU 24. THERE REMAINS A DISPARITY IN MODEL GUIDANCE
BEYOND TAU 36. GFS AND ECMWF INDICATE THE REMNANTS OF THE LLCC WILL
TRACK BACK OVER THE SEA OF JAPAN, WHILE GFDN, WBAR, AND NGPS
INDICATE A CONTINUED TRACK INTO NORTHEASTERN CHINA. THE CURRENT
FORECAST FAVORS THE DYNAMIC MODELS INDICATING A TURN INTO THE
SEA OF JAPAN. THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.//
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