WTXS31 PGTW 230900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
230600Z --- NEAR 12.9S 88.3E
MOVEMENT PAST SIX HOURS - 215 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 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
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.9S 88.3E
---
FORECASTS:
12 HRS, VALID AT:
231800Z --- 14.0S 87.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 210 DEG/ 07 KTS
---
24 HRS, VALID AT:
240600Z --- 15.2S 87.0E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 200 DEG/ 06 KTS
---
36 HRS, VALID AT:
241800Z --- 16.4S 86.5E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 195 DEG/ 06 KTS
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EXTENDED OUTLOOK:
48 HRS, VALID AT:
250600Z --- 17.6S 86.2E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 170 DEG/ 07 KTS
---
72 HRS, VALID AT:
260600Z --- 20.5S 86.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 190 DEG/ 05 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:
270600Z --- 22.6S 86.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
230900Z POSITION NEAR 13.2S 88.1E.
TROPICAL CYCLONE (TC) 21S, LOCATED APPROXIMATELY 505 NM WEST OF
COCOS ISLAND, HAS TRACKED SOUTHWESTWARD AT 07 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS TC 21S HAS
MAINTAINED CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL CIRCULATION
CENTER (LLCC). INITIAL POSITION IS BASED ON ANIMATED MULTISPECTRAL
IMAGERY AND INITIAL INTENSITY IS BASED ON DVORAK INTENSITY ESTIMATES
FROM PGTW AND FMEE. UPPER LEVEL ANALYSIS INDICATES TC 21S IS LOCATED
EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN AN AREA OF LOW VERTICAL
WIND SHEAR. THE SYSTEM IS TRACKING ALONG THE WESTERN PERIPHERY OF A
LOW TO MID LEVEL STEERING RIDGE TO THE EAST. TC 21S IS EXPECTED TO
INTENSIFY UP TO 55 KNOTS WITH FAVORABLE WIND SHEAR CONDITIONS AND
HIGH OCEAN HEAT CONTENT ALONG ITS TRACK. BY TAU 72, THE SYSTEM WILL
BEGIN TO WEAKEN DUE TO AN INCREASE IN VERTICAL WIND SHEAR, CAUSED BY
THE APPROACH OF AN UPPER LEVEL TROUGH FROM THE SOUTHWEST. TC 21S WILL
DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER BY TAU 96. THE
AVAILABLE NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT EXCEPT FOR
UKMET, WHICH IS BRINGING THE SYSTEM ON A SHARP WESTWARD TRACK AFTER
TAU 24. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 230600Z IS 14 FEET. NEXT
WARNINGS AT 232100Z AND 240900Z.//
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