Subject: Pacific-NW: 1. Typhoon 15w (megi) Warning Nr 030

From: SIU Weather Processor <[email-masked]>
Date: Wed, 20 Oct 2010 03:07:08 -0500

WTPN31 PGTW 200900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TYPHOON 15W (MEGI) WARNING NR 030
   01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   200600Z --- NEAR 17.7N 117.2E
     MOVEMENT PAST SIX HOURS - 340 DEGREES AT 05 KTS
     POSITION ACCURATE TO WITHIN 040 NM
     POSITION BASED ON EYE FIXED BY A COMBINATION OF
     SATELLITE, SYNOPTIC DATA AND EXTRAPOLATION
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 055 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT
                            185 NM SOUTHEAST QUADRANT
                            190 NM SOUTHWEST QUADRANT
                            190 NM NORTHWEST QUADRANT
   REPEAT POSIT: 17.7N 117.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   201800Z --- 18.6N 117.1E
   MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 185 NM NORTHEAST QUADRANT
                            180 NM SOUTHEAST QUADRANT
                            190 NM SOUTHWEST QUADRANT
                            190 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 360 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   210600Z --- 19.6N 117.1E
   MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 065 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT
                            180 NM SOUTHEAST QUADRANT
                            190 NM SOUTHWEST QUADRANT
                            190 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 010 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   211800Z --- 21.0N 117.3E
   MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            090 NM SOUTHWEST QUADRANT
                            090 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
                            180 NM SOUTHEAST QUADRANT
                            170 NM SOUTHWEST QUADRANT
                            170 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 350 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   220600Z --- 22.2N 117.1E
   MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            080 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT
                            170 NM SOUTHEAST QUADRANT
                            160 NM SOUTHWEST QUADRANT
                            160 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 335 DEG/ 04 KTS
    ---
   72 HRS, VALID AT:
   230600Z --- 23.7N 116.4E
   MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
                            035 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
                            135 NM SOUTHEAST QUADRANT
                            135 NM SOUTHWEST QUADRANT
                            140 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 315 DEG/ 04 KTS
    ---
   LONG RANGE OUTLOOK:
   NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
   ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY
   NEAR 20 KT EACH DAY.
    ---
   96 HRS, VALID AT:
   240600Z --- 24.7N 115.3E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
200900Z POSITION NEAR 17.9N 117.2E.
TYPHOON (TY) 15W (MEGI), LOCATED APPROXIMATELY 320 NM SOUTH-SOUTHEAST
OF HONG KONG, HAS TRACKED NORTH-NORTHWESTWARD AT 05 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL IMAGERY SHOWS THE SYSTEM HAS
MAINTAINED A RAGGED EYE AND OVERALL DEEP CONVECTION. ADDITIONALLY,
GOOD RADIAL OUTFLOW, ESPECIALLY ON THE POLEWARD CHANNEL, HAS
PERSISTED OVER THE SYSTEM. THE CURRENT INTENSITY AND POSITION ARE
BASED ON DVORAK EYE FIXES FROM PGTW AND RJTD WITH GOOD CONFIDENCE.
UPPER LEVEL ANALYSIS INDICATES TY 15W IS TO THE SOUTH OF A RIDGE AXIS
IN AN AREA OF LOW VERTICAL WIND SHEAR (VWS). IT IS CURRENTLY TRACKING
ALONG THE SOUTHWEST EXTENSION OF A DEEP-LAYERED SUBTROPICAL RIDGE TO
THE NORTHEAST AND MOVING POLEWARD TOWARDS A BREAK IN THE RIDGE CAUSED
BY AN APPROACHING MID-LATITUDE TROUGH THAT IS DIGGING SOUTHEAST INTO
SOUTHEAST CHINA. THE SYSTEM IS EXPECTED TO CONTINUE MOVING POLEWARD
UP TO TAU 72. AFTER TAU 72, A BRANCH OF THE STR OVER SOUTH CENTRAL
CHINA WILL REBUILD AND CAUSE THE SYSTEM TO MOVE ON A MORE
NORTHWESTWARD TRAJECTORY AND MAKE LANDFALL BEFORE TAU 96 NORTHEAST OF
HONG KONG. THE AVAILABLE NUMERIC GUIDANCE ARE IN LOOSE AGREEMENT WITH
GFS ON THE EXTREME RIGHT OF THE ENVELOPE AND ECMWF ON THE LEFT. THIS
FORECAST IS IN THE MIDDLE AND JUST TO THE LEFT OF JTWC CONSENSUS TO
OFFSET GFS'S UNLIKELY EASTWARD DEFLECTION.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 200600Z IS 36 FEET. NEXT WARNINGS
AT 201500Z, 202100Z, 210300Z AND 210900Z.//

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