Updated: 17 June 2020
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| Tropical Cyclones
[Index] | Tropical Cyclone IMANI : JTWC Advisories |
| Season 2009-2010 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
| ---> Tropical Cyclone IMANI Track Map and Data |
WTXS21 PGTW 20100322 02:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
145 NM EITHER SIDE OF A LINE FROM 8.6S 89.8E TO 15.1S 87.2E WITH-
IN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY IS-
SUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS
IN THE AREA ARE ESTIMATED TO BE 30 TO 35 KNOTS. METSAT IMAGERY AT
212330Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 9.9S
89.4E. THE SYSTEM IS MOVING SOUTH-SOUTHWESTWARD AT 12 KNOTS.
2. THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.5S 89.0E, IS NOW
LOCATED NEAR 9.9S 89.4E, APPROXIMATELY 460 NM WEST-NORTHWEST OF
COCOS ISLAND. RECENT ANIMATED INFRARED SATELLITE IMAGERY AND A
212326Z SSMI PASS SHOW A WELL ORGANIZED LOW LEVEL CIRCULATION CENTER
(LLCC) WITH A DEEP BAND OF CONVECTION WRAPPING FROM THE SOUTHERN
PERIPHERY INTO THE NORTHEASTERN QUADRANT OF THE LLCC. SURFACE
CONDITIONS REMAIN FAVORABLE WITH SEA SURFACE TEMPERATURES NEAR 29
CELSIUS. UPPER LEVEL ANALYSIS INDICATES THAT AN ANTICYCLONE TO THE
EAST OF THE LLCC IS PROVIDING GOOD POLEWARD OUTFLOW WITH VERTICAL
WIND SHEAR (VWS) DECREASING OVER THE PAST 12 HOURS TO A MODERATE
LEVEL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB.
BASED ON THE CONSOLIDATION OF THE LLCC, FAVORABLE SURFACE
CONDITIONS, AND VWS SUPPORTING UPPER LEVEL OUTFLOW, THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
230230Z.//
=========================================================================
WTXS31 PGTW 20100322 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 001//
RMKS/
1. TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
221800Z --- NEAR 11.5S 89.2E
MOVEMENT PAST SIX HOURS - 190 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 11.5S 89.2E
---
FORECASTS:
12 HRS, VALID AT:
230600Z --- 12.7S 89.2E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 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: 200 DEG/ 06 KTS
---
24 HRS, VALID AT:
231800Z --- 13.9S 88.8E
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: 205 DEG/ 07 KTS
---
36 HRS, VALID AT:
240600Z --- 15.2S 88.1E
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: 200 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
241800Z --- 16.7S 87.6E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 185 DEG/ 06 KTS
---
72 HRS, VALID AT:
251800Z --- 19.0S 87.3E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 155 DEG/ 08 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:
261800Z --- 22.0S 88.8E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 120 HR POSIT: 195 DEG/ 07 KTS
---
120 HRS, VALID AT:
271800Z --- 24.9S 88.0E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
222100Z POSITION NEAR 11.8S 89.2E.
TROPICAL CYCLONE (TC) 21S, LOCATED APPROXIMATELY 450 NM WEST OF
COCOS ISLAND, HAS TRACKED SOUTHWARD AT 05 KNOTS OVER THE PAST 06
HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS CONVECTIVE BANDING
WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC) AND A 221514Z
ASCAT PASS DEPICTS A TIGHT LLCC WITH 35 TO 40 KNOT WINDS. INITIAL
POSITION IS BASED ON ANIMATED INFRARED IMAGERY AND INITIAL INTENSITY
IS BASED ON PGTW/FMEE DVORAK INTENSITY ESTIMATES OF 35 KNOTS. UPPER
LEVEL ANALYSIS INDICATES TC 21S IS LOCATED EQUATORWARD OF THE
SUBTROPICAL RIDGE AXIS PROVIDING GOOD RADIAL OUTFLOW IN THE NORTHERN
SEMI-CIRCLE. AN UPPER LEVEL LOW LOCATED TO THE SOUTHEAST IS
SUPPORTING A POLEWARD OUTFLOW CHANNEL. TC 21S IS TRACKING SOUTHWARD
ALONG THE WESTERN PERIPHERY OF A LOW TO MID LEVEL STEERING RIDGE
(SR) AND WILL CONTINUE THROUGH TAU 72, WHEN AN UPPER LEVEL TROUGH
WILL CAUSE A WEAKENING IN THE SR AND ALLOW TC 21S TO TURN
SOUTHEASTWARD. AT THAT TIME, THE SYSTEM WILL ALSO BEGIN TO WEAKEN
DUE TO AN INCREASE IN VERTICAL WIND SHEAR, CAUSED BY THE UPPER LEVEL
TROUGH. ONCE TC 21S WEAKENS, IT WILL BEGIN TO TRACK WITH THE LOW
LEVEL FLOW TO THE SOUTHWEST AND DISSIPATE BELOW TC STRENGTH BY TAU
120. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE
SOUTHWARD TRACK. THIS WARNING SUPERSEDES AND CANCELS REF A,
NAVMARFCSTCEN 220221ZMAR 10 TROPICAL CYCLONE FORMATION ALERT (WTXS21
PGTW 220230). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221800Z IS 12 FEET.
NEXT WARNINGS AT 230900Z AND 232100Z.//
=========================================================================
WTXS31 PGTW 20100323 09:00z
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
---
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.//
=========================================================================
WTXS31 PGTW 20100323 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
231800Z --- NEAR 13.8S 87.5E
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 - 050 KT, GUSTS 065 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
REPEAT POSIT: 13.8S 87.5E
---
FORECASTS:
12 HRS, VALID AT:
240600Z --- 14.8S 86.5E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 210 DEG/ 06 KTS
---
24 HRS, VALID AT:
241800Z --- 15.9S 85.8E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 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 36 HR POSIT: 200 DEG/ 06 KTS
---
36 HRS, VALID AT:
250600Z --- 17.0S 85.4E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 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: 190 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
251800Z --- 18.2S 85.2E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 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: 185 DEG/ 06 KTS
---
72 HRS, VALID AT:
261800Z --- 20.4S 85.0E
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/ 06 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:
271800Z --- 22.7S 84.5E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
232100Z POSITION NEAR 14.1S 87.2E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 555 NM WEST-
SOUTHWEST OF COCOS ISLAND, HAS TRACKED SOUTHWESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
IMPROVED CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL CIRCULATION
CENTER WITHIN THE PAST 12 HOURS AND A 231513Z TRMM MICROWAVE IMAGE
DEPICTS THE DEEPEST CONVECTION IS WRAPPING AROUND THE WESTERN
PERIPHERY. INITIAL INTENSITY IS BASED ON PGTW AND KNES DVORAK
ESTIMATES RANGING FROM 45 TO 55 KNOTS. THE SYSTEM HAS INTENSIFIED
UNDER AN AREA OF DIVERGENCE ALOFT AND DECREASED VERTICAL WIND SHEAR.
IMANI IS CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF A
SUBTROPICAL RIDGE (STR) AND WILL CONTINUE TO DO SO UNTIL A MID-
LATITUDE, UPPER LEVEL TROUGH REORIENTS THE STEERING RIDGE AND
ENABLES TC 21S TO TURN SOUTHWARD. AS IMANI TRACKS SOUTHWARD, THIS
TROUGH SHOULD ALSO CAUSE AN INCREASE IN VERTICAL WIND SHEAR AFTER
TAU 48 AND BEGIN TO WEAKEN THE SYSTEM. TC 21S WILL DISSIPATE AS A
SIGNIFICANT TROPICAL CYCLONE OVER WATER BY TAU 72. NUMERICAL MODEL
GUIDANCE IS IN FAIR AGREEMENT WITH THE OVERALL TRACK SCENARIO THOUGH
SOME OF THE TRACKERS DIFFER IN HOW FAR TC 21S WILL TRACK WESTWARD
BEFORE IT TURNS SOUTHWARD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
231800Z IS 15 FEET. NEXT WARNINGS AT 240900Z AND 242100Z.//
=========================================================================
WTXS31 PGTW 20100324 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
240600Z --- NEAR 15.7S 86.3E
MOVEMENT PAST SIX HOURS - 215 DEGREES AT 11 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
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 - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 15.7S 86.3E
---
FORECASTS:
12 HRS, VALID AT:
241800Z --- 17.2S 85.5E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 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 24 HR POSIT: 200 DEG/ 07 KTS
---
24 HRS, VALID AT:
250600Z --- 18.5S 85.0E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 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 36 HR POSIT: 195 DEG/ 06 KTS
---
36 HRS, VALID AT:
251800Z --- 19.6S 84.7E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 180 DEG/ 09 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
260600Z --- 21.5S 84.7E
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 - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 185 DEG/ 04 KTS
---
72 HRS, VALID AT:
270600Z --- 23.0S 84.5E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
240900Z POSITION NEAR 16.1S 86.1E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 745 NM
WEST-SOUTHWEST OF COCOS ISLAND, HAS TRACKED SOUTH-SOUTHWESTWARD AT 07
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS THE SYSTEM HAS MAINTAINED CONVECTIVE BANDING WRAPPING INTO A
LOW LEVEL CIRCULATION CENTER. INITIAL POSITION AND INTENSITY ARE
BASED ON DVORAK FIXES FROM PGTW, KNES, AND FMEE. IMANI IS EXPECTED TO
CONTINUE TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE
(STR) UNTIL TAU 36 BEFORE AN APPROACHING MID-
LATITUDE TROUGH REORIENTS THE STEERING RIDGE AND ENABLES TC 21S TO
TURN SOUTHWARD. THIS WILL ALSO CAUSE AN INCREASE IN VERTICAL WIND
SHEAR AND BEGIN TO WEAKEN THE SYSTEM. TC 21S WILL DISSIPATE AS A
SIGNIFICANT TROPICAL CYCLONE OVER WATER BY TAU 72. NUMERICAL MODEL
GUIDANCE IS IN FAIR AGREEMENT UP TO TAU 36 BEFORE THEY SPREAD OUT
WITH GFS AND ECMWF FAVORING A WEAKER SYSTEM TRACKING MORE WESTWARD
TRACK AND TCLP TO THE THE LEFT OF THE ENVELOPE FAVORING A STRONGER
SYSTEM STEERED BY THE STRONG WESTERLIES. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 240600Z IS 16 FEET. NEXT WARNINGS AT 242100Z AND 250900Z.
=========================================================================
WTXS31 PGTW 20100324 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
241800Z --- NEAR 17.7S 85.5E
MOVEMENT PAST SIX HOURS - 195 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.7S 85.5E
---
FORECASTS:
12 HRS, VALID AT:
250600Z --- 19.3S 85.0E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 190 DEG/ 06 KTS
---
24 HRS, VALID AT:
251800Z --- 20.4S 84.8E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 185 DEG/ 05 KTS
---
36 HRS, VALID AT:
260600Z --- 21.4S 84.7E
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 - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 180 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
261800Z --- 22.2S 84.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
242100Z POSITION NEAR 18.1S 85.4E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 745 NM WEST-
SOUTHWEST OF COCOS ISLAND, HAS TRACKED SOUTH-SOUTHWESTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS A BANDING EYE WITH TIGHTLY-WRAPPED DEEP CONVECTION WHILE
RECENT MICROWAVE IMAGERY REVEALS A LOW-LEVEL EYE FEATURE. OVER THE
LAST 12 HOURS, THE SYSTEM HAS MAINTAINED AT 65-KNOTS DUE TO ENHANCED
POLEWARD OUTFLOW AHEAD OF A DIGGING MID-LATITUDE TROUGH. TC 21S IS
EXPECTED TO DRIFT GENERALLY SOUTHWARD ALONG THE WESTERN PERIPHERY OF
THE SUBTROPICAL STEERING RIDGE THROUGHOUT THE FORECAST PERIOD. AS
THE SYSTEM CONTINUES TO MOVE SOUTH, IT WILL START TO EXPERIENCE
HOSTILE VERTICAL WIND SHEAR CAUSED BY THE DIGGING UPPER-LEVEL TROUGH
TO THE WEST BY TAU 24 AND DISSIPATE AS A SIGNIFICANT TROPICAL
CYCLONE BY TAU 48. THE MODEL GUIDANCE IS IN GENERAL AGREEMENT WITH A
SOUTHWARD TRACK THOUGH SOME OF THE MODELS ERRONEOUSLY INITIALIZE A
WEAKER SYSTEM THAT WILL TRACK WITH THE LOW-LEVEL EASTERLY FLOW
(UKMO, ECMWF). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241800Z IS 17 FEET.
NEXT WARNINGS AT 250900Z AND 252100Z.//
=========================================================================
WTXS31 PGTW 20100325 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 006//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 006
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
250600Z --- NEAR 19.1S 85.5E
MOVEMENT PAST SIX HOURS - 165 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
110 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
REPEAT POSIT: 19.1S 85.5E
---
FORECASTS:
12 HRS, VALID AT:
251800Z --- 20.4S 85.6E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 180 DEG/ 05 KTS
---
24 HRS, VALID AT:
260600Z --- 21.4S 85.6E
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 - 070 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 190 DEG/ 05 KTS
---
36 HRS, VALID AT:
261800Z --- 22.4S 85.4E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
250900Z POSITION NEAR 19.4S 85.5E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 780 NM
SOUTHWEST OF COCOS ISLAND, HAS TRACKED SOUTH-SOUTHEASTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY SHOWS A DEEPENING OF CENTRAL CONVECTION,
PARTICULARLY WITHIN THE NORTHWEST QUADRANT, THAT IS OUTLINING AN
ASYMMETRIC AND CLOUD-FILLED EMBEDDED CENTER. CONVECTION HAS ALSO
BECOME SHEARED TO THE SOUTHEAST AHEAD OF AN UPPER LEVEL TROUGH THAT
IS DIGGING EQUATORWARD A FEW DEGREES UPSTREAM. THE INITIAL INTENSITY
OF 70 KNOTS IS LOWER THAN THE 4.5 DVORAK CURRENT INTENSITY (CI)
ESTIMATES FROM PGTW AND FMEE TO ACCOUNT FOR A LOWER FINAL-T NUMBER
FROM PGTW (REPRESENTING WEAKENING). IMANI IS FORECAST TO TRACK
POLEWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE DEEP LAYER
SUBTROPICAL RIDGE AXIS TOWARDS A TROUGH-INDUCED WEAKNESS NEAR 30S.
VERTICAL WIND SHEAR WILL QUICKLY ELEVATE THROUGHOUT THE FORECAST,
BECOMING EXCESSIVE BY TAU 36. DISSIPATION IS EXPECTED AROUND THE
SAME TIME. AS A WEAKER AND SHALLOWER SYSTEM THE LOW LEVEL
CIRCULATION CENTER SHOULD TREND TOWARDS THE WEST WHILE CONTINUING TO
DRIFT POLEWARD. THE MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A
POLEWARD TRACK WITH THE EXCEPTION OF EGRR, WHICH CONTINUES TO
INITIALIZE A WEAKER AND SHALLOWER SYSTEM. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 250600Z IS 17 FEET. NEXT WARNINGS AT 252100Z AND 260900Z.//
=========================================================================
WTXS31 PGTW 20100325 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
251800Z --- NEAR 20.5S 86.1E
MOVEMENT PAST SIX HOURS - 150 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
135 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
REPEAT POSIT: 20.5S 86.1E
---
FORECASTS:
12 HRS, VALID AT:
260600Z --- 21.7S 86.6E
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 - 090 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 165 DEG/ 06 KTS
---
24 HRS, VALID AT:
261800Z --- 22.8S 86.9E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
252100Z POSITION NEAR 20.8S 86.2E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 230 NM
SOUTHWEST OF THE COCOS ISLANDS, HAS TRACKED SOUTH-SOUTHEASTWARD AT
06 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS DECLINING DEEP CONVECTION CONFINED TO THE SOUTHEASTERN
PORTION OF THE SYSTEM. ADDITIONALLY, THE UPPER-LEVEL TROUGH LOCATED
TO THE NORTHWEST OF TC IMANI IS IMPINGING CONVECTIVE DEVELOPMENT ON
THE WEESTERN SIDE OF THE CYCLONE. THE CURRENT POSITION IS SUPPORTED
BY A 251500Z TRMM MICROWAVE IMAGE AND THE CURRENT INTENSITY IS BASED
ON THE LOWER END OF DVORAK ESTIMATES (PGTW, FMEE, AND KNES) RANGING
FROM 55 TO 77 KNOTS. TC 21S IS EXPECTED TO CONTINUE TRACKING
GENERALLY SOUTHEASTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE AND WEAKEN STEADILY OVER THE NEXT 24 HOURS DUE TO
HOSTILE VERTICAL WIND SHEAR AND THE ENTRAINMENT OF DRYER AIR, WHICH
IS EVIDENT IN RECENT MICROWAVE IMAGERY. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 251800Z IS 15 FEET. NEXT WARNINGS AT 260900Z.//
=========================================================================
WTXS31 PGTW 20100326 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 008//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 008
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
260600Z --- NEAR 21.1S 86.3E
MOVEMENT PAST SIX HOURS - 120 DEGREES AT 02 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
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 21.1S 86.3E
---
FORECASTS:
12 HRS, VALID AT:
261800Z --- 21.7S 86.6E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 180 DEG/ 04 KTS
---
24 HRS, VALID AT:
270600Z --- 22.6S 86.6E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
260900Z POSITION NEAR 21.3S 86.4E.
TROPICAL CYCLONE (TC) 21S (IMANI), LOCATED APPROXIMATELY 810 NM
SOUTHWEST OF THE COCOS ISLANDS, HAS TRACKED EAST-SOUTHEASTWARD AT
02 KNOTS OVER THE PAST SIX HOURS. THE LOW LEVEL CIRCULATION CENTER
(LLCC) IS NOW FULLY EXPOSED ON THE NORTH SIDE OF WEAK AND MODERATELY
SHEARED CONVECTION. CONVECTION IS ALSO BEING DAMPENED BY STRONG
CONVERGENCE ALOFT ASSOCIATED WITH AN UPPER LEVEL TROUGH. A 260303Z
ASCAT PASS INDICATES THAT LLCC IS STILL 40 TO 45 KNOTS, WHICH IS
STRONGER THAN THE DEGRADED CONVECTIVE SIGNATURE MAY AT FIRST
SUGGEST. NONETHELESS, VERTICAL WIND SHEAR WILL CONTINUE TO ELEVATE
AND THE SYSTEM WILL WEAKEN BELOW THE WARNING THRESHOLD OF 35 KNOTS
WITHIN THE NEXT DAY. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 260600Z IS
13 FEET. NEXT WARNINGS AT 262100Z.//
=========================================================================
WTXS31 PGTW 20100326 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (IMANI) WARNING NR 009//
RMKS/
1. TROPICAL CYCLONE 21S (IMANI) WARNING NR 009
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
261800Z --- NEAR 21.2S 86.5E
MOVEMENT PAST SIX HOURS - 225 DEGREES AT 01 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 21.2S 86.5E
---
FORECASTS:
12 HRS, VALID AT:
270600Z --- 21.4S 86.0E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 230 DEG/ 05 KTS
---
24 HRS, VALID AT:
271800Z --- 22.0S 85.2E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
262100Z POSITION NEAR 21.2S 86.4E.
TROPICAL CYCLONE (TC) 21S (INMANI), LOCATED APPROXIMATELY 800 NM
SOUTHWEST OF THE COCOS ISLANDS, HAS REMAINED QUASISTATIONARY OVER
THE LAST SIX HOURS. THE LOW LEVEL CIRCULATION CENTER REMAINS FULLY
EXPOSED AND QUASISTATIONARY AS THE MID- TO UPPER-LEVEL CIRCULATION
DECOUPLES TO THE SOUTHEAST IN THE WESTERLY UPPER-LEVEL FLOW. A
261526Z ASCAT PASS SHOWS A WELL DEFINED CIRCULATION WITH 35 TO 40KT
UNFLAGGED WINDS, BUT WITH THE AMOUNT OF VERTICAL WIND SHEAR (VWS) IN
THE AREA, THE SYSTEM IS EXPECTED TO RAPIDLY WEAKEN. ENVIRONMENTAL
ANALYSIS INDICATES CLOSE TO 40KTS OF VWS OVER THE SYSTEM ALONG WITH
SEA SURFACE TEMPERATURES NEAR 26 DEGREES CELCIUS. NUMERICAL MODEL
GUIDANCE IS IN RELATIVELY GOOD AGREEMENT WITH THE LLCC TRACKING TO
THE SOUTHWEST WITH THE EXCEPTIONS OF THE BAROTROPIC MODEL WBAR AND
TCLAPS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT
TYPHOON WARNING CENTER (NAVMARFCSTCEN). THE SYSTEM WILL BE CLOSELY
MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 261800Z IS 15 FEET.
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
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Document: tropical_cyclone_imani_jtwc_advisories.htm
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