Tropical Cyclones
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Tropical Cyclone ERROL : JTWC Advisories
Season 2010-2011 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH]
---> Tropical Cyclone ERROL Track Map and Data

WTXS21 PGTW 20110414 21:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 13.1S 126.9E TO 12.5S 123.1E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 28 TO 33 KNOTS. METSAT IMAGERY
AT 141800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 13.0S
126.4E. THE SYSTEM IS MOVING SOUTH-SOUTHEASTWARD AT 04 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.5S
126.6E IS NOW LOCATED NEAR 13.0S 126.4E, APPROXIMATELY 260 NM W OF
DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE IMAGERY AND A RADAR
LOOP FROM WYNDHAM, AUSTRALIA DEPICT CURVED LOW LEVEL INFLOW WITH A
MAJORITY OF THE DEEPEST CONVECTION ALONG THE SOUTHERN PERIPHERY. A
14/1733Z TRMM 37H MICROWAVE SATELLITE IMAGE INDICATES CURVED BANDING
WRAPPING INTO A WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC).
OBSERVATIONS FROM TROUGHTON ISLAND, JUST SOUTH OF THE LLCC, INDICATE
1006.9 MB MSLP WITH MAX WINDS AT 23 KNOTS, GUSTING TO 29 KNOTS
(15/0500 WST). MSLP HAS SHOWN A 2 MB PRESSURE DROP OVER THE PAST 24
HOURS. THE LLCC REMAINS LOCATED BENEATH THE RIDGE AXIS IN A REGION
OF LOW VERTICAL WIND SHEAR AND STRONG DIFFLUENCE ALOFT. ANIMATED
WATER VAPOR IMAGERY CONTINUES TO SHOW INCREASED POLEWARD OUTFLOW
AHEAD OF A PASSING MID-LATITUDE TROUGH. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED TO BE NEAR 28-32 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. DUE TO INCREASED DEEP
CONVECTION WRAPPING AROUND THE LLCC AND AN INCREASE IN OBSERVED
WINDS, 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
152130Z.//
=========================================================================
WTXS31 PGTW 20110415 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (TWENTY-ONE) WARNING NR 001//
RMKS/
1. TROPICAL CYCLONE 21S (TWENTY-ONE) 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:
   150000Z --- NEAR 13.1S 126.3E
     MOVEMENT PAST SIX HOURS - 205 DEGREES AT 02 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 - 040 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   REPEAT POSIT: 13.1S 126.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   151200Z --- 12.8S 125.8E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 295 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   160000Z --- 12.3S 124.6E
   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 - 055 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 290 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   161200Z --- 11.9S 123.4E
   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 - 055 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 280 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   170000Z --- 11.6S 121.9E
   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 - 055 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 275 DEG/ 07 KTS
    ---
   72 HRS, VALID AT:
   180000Z --- 11.3S 119.2E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 270 DEG/ 07 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:
   190000Z --- 11.4S 116.2E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 265 DEG/ 07 KTS
    ---
   120 HRS, VALID AT:
   200000Z --- 11.7S 113.3E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
150300Z POSITION NEAR 13.0S 126.2E.
TROPICAL CYCLONE (TC) 21S (TWENTY-ONE) LOCATED APPROXIMATELY 270 NM
WEST OF DARWIN, AUSTRALIA, HAS DRIFTED SOUTH-SOUTHWESTWARD AT 02
KNOTS DURING THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC)
WITH DEEP CONVECTIVE BANDING ALONG THE SOUTHERN AND WESTERN
PERIPHERIES. A 14/2208Z SSMIS 91H MICROWAVE SATELLITE IMAGE SHOWS
SPIRAL BANDING AND DEEP CONVECTION WRAPPING AROUND THE LLCC. THERE
IS HIGH CONFIDENCE IN THE CURRENT POSITION BASED ON THE
AFOREMENTIONED MICROWAVE IMAGE. THE CURRENT INTENSITY IS BASED ON
PGTW, KNES, AND ADRM DVORAK INTENSITY ESTIMATES RANGING FROM 30 TO
45 KNOTS. OBSERVATIONS FROM TROUGHTON ISLAND, JUST SOUTH OF THE
LLCC, INDICATE 1008.8 MB MSLP WITH MAX WINDS AT 28 KNOTS, GUSTING TO
36 KNOTS (15/00Z). MSLP AT TROUGHTON HAS SHOWN A 1.3 MB PRESSURE
DROP OVER THE PAST 24 HOURS. THE LLCC REMAINS LOCATED BENEATH THE
RIDGE AXIS IN A REGION OF LOW VERTICAL WIND SHEAR AND STRONG
DIFFLUENCE ALOFT. ANIMATED WATER VAPOR IMAGERY CONTINUES TO SHOW
INCREASED POLEWARD AND EASTWARD OUTFLOW AS A MID-LATITUDE TROUGH
PASSES TO THE SOUTH. THE SYSTEM IS CURRENTLY IN A WEAK STEERING
ENVIRONMENT, BUT IS EXPECTED TO BEGIN TRACKING WEST-NORTHWESTWARD
DURING THE NEXT 12-24 HOURS UNDER THE INFLUENCE OF A MID-LEVEL
STEERING RIDGE BUILDING OVER WESTERN AUSTRALIA. THIS SYSTEM IS
EXPECTED TO REACH A PEAK INTENSITY OF 55 KNOTS WITHIN 24 HOURS AND
MAINTAIN INTENSITY THROUGH TAU 72 UNDER FAVORABLE ENVIRONMENTAL
CONDITIONS (LOW VERTICAL WIND SHEAR AND HIGH SST) BEFORE
ENCOUNTERING A DRY, HIGH-SHEAR ENVIRONMENT WEST OF 120E. MODEL
GUIDANCE IS IN FAIR AGREEMENT WITH THE EXCEPTION OF WBAR WHICH
TRACKS THE SYSTEM INLAND INTO THE SUBTROPICAL RIDGE. THIS FORECAST
IS WITHIN THE AIDS ENVELOPE AND IS SLIGHTLY FASTER THEN CONSENSUS TO
ACCOUNT FOR THIS MODEL ERROR. THIS WARNING SUPERSEDES AND CANCELS
REF A, NAVMARFCSTCEN 142121Z APR 11 TROPICAL CYCLONE FORMATION ALERT
=========================================================================
WTXS31 PGTW 20110415 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   151200Z --- NEAR 12.3S 125.8E
     MOVEMENT PAST SIX HOURS - 340 DEGREES AT 05 KTS
     POSITION ACCURATE TO WITHIN 060 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 - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.3S 125.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   160000Z --- 11.8S 124.9E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 285 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   161200Z --- 11.6S 124.0E
   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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 280 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   170000Z --- 11.3S 122.6E
   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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 275 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   171200Z --- 11.2S 121.2E
   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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 265 DEG/ 07 KTS
    ---
   72 HRS, VALID AT:
   181200Z --- 11.4S 118.3E
   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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 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:
   191200Z --- 11.8S 115.9E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 265 DEG/ 09 KTS
    ---
   120 HRS, VALID AT:
   201200Z --- 12.2S 112.3E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
151500Z POSITION NEAR 12.2S 125.6E.
TROPICAL CYCLONE (TC) 21S (ERROL) LOCATED APPROXIMATELY 310 NM
WEST OF DARWIN, AUSTRALIA, HAS TRACKED NORTH-NORTHWESTWARD AT 05
KNOTS DURING THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS DEEP CONVECTIVE BANDING WRAPPING INTO A SMALL (< 200NM)
LOW LEVEL CIRCULATION CENTER (LLCC). A 151136Z SSMIS MICROWAVE IMAGE
DEPICTS A SYMMETRIC LLCC WITH IMPROVEMENT IN THE DEEP CONVECTIVE
BANDING ALTHOUGH IR DOES NOT INDICATE THIS. THEREFORE, THE INITIAL
INTENSITY IS HIGHER THAN THE PGTW AND KNES DVORAK ESTIMATES OF 35
KNOTS. THE INITIAL POSITION IS BASED ON THE SSMIS IMAGE WITH FAIR
CONFIDENCE. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM MAINTAINS GOOD
RADIAL OUTFLOW AND IS LOCATED BENEATH THE SUBTROPICAL RIDGE AXIS IN
AN AREA OF LOW VERTICAL WIND SHEAR. TC 21S IS CURRENTLY TRACKING
ALONG THE NORTHEASTERN PERIPHERY OF A MID-LEVEL STEERING RIDGE. AS
THE STEERING RIDGE BUILDS OVER WESTERN AUSTRALIA AND REORIENTS, TC
21S IS FORECAST TO BEGIN TO TURN NORTHWESTWARD OVER THE NEXT 12
HOURS AND THEN TRACK GENERALLY WESTWARD THROUGHOUT THE FORECAST
PERIOD. THE SYSTEM SHOULD CONTINUE TO INTENSIFY UNDER THE FAVORABLE
UPPER LEVEL ENVIRONMENTAL CONDITIONS AND WARM SEA SURFACE
TEMPERATURES. HOWEVER, AFTER TAU 48, THE SYSTEM SHOULD ENCOUNTER DRY
AIR AND BEGIN TO WEAKEN. NUMERICAL MODEL GUIDANCE IS IN FAIR
AGREEMENT WITH GFDN AND WBAR AS THE SOUTHERNMOST OUTLIERS. ALSO, GFS
BEGINS ERRONEOUSLY TRACKING THE SYSTEM SOUTHWARD AROUND TAU 48.
THEREFORE, THIS FORECAST IS SLIGHTLY FASTER THAN MODEL CONSENSUS TO
ACCOUNT FOR GFS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 151200Z IS 15
FEET. NEXT WARNINGS AT 160300Z AND 161500Z.//
=========================================================================
WTXS31 PGTW 20110416 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   160000Z --- NEAR 11.6S 124.9E
     MOVEMENT PAST SIX HOURS - 320 DEGREES AT 06 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 - 055 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.6S 124.9E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   161200Z --- 11.1S 124.0E
   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
                            055 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 290 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   170000Z --- 10.7S 123.0E
   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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 280 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   171200Z --- 10.5S 121.9E
   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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   180000Z --- 10.7S 120.7E
   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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 255 DEG/ 08 KTS
    ---
   72 HRS, VALID AT:
   190000Z --- 11.5S 117.7E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 255 DEG/ 07 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:
   200000Z --- 12.3S 114.9E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 255 DEG/ 10 KTS
    ---
   120 HRS, VALID AT:
   210000Z --- 13.3S 111.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
160300Z POSITION NEAR 11.5S 124.7E.
TROPICAL CYCLONE (TC) 21S (ERROL), LOCATED APPROXIMATELY 355 NM
WEST OF DARWIN, AUSTRALIA, HAS TRACKED NORTHWESTWARD AT 06 KNOTS OVER
THE PAST SIX HOURS. ANIMATED WATER VAPOR IMAGERY SHOWS CONVECTIVE
BANDING ALONG THE NORTHWEST QUADRANT HAS DEEPENED AND WRAPPED TIGHTER
INTO THE LOW LEVEL CIRCULATION CENTER AS POLEWARD OUTFLOW REMAINED
ROBUST. A 152156Z SSMIS MICROWAVE IMAGE SUPPORTS THE DEEPENED
CONVECTION AND TIGHT WRAPPING. THE INITIAL INTENSITY
IS BASED ON DVORAK INTENSITY OF T3.0 FROM APRF AND KNES. THE INITIAL
POSITION IS BASED ON ANIMATED MULTISPECTRAL IMAGERY WITH FAIR
CONFIDENCE. TC 21S IS CURRENTLY TRACKING ALONG THE NORTHEASTERN
PERIPHERY OF A MID-LEVEL STEERING RIDGE. AS THE RIDGE BUILDS AND
REORIENTS, THE SYSTEM IS EXPECTED TO TURN MORE WESTWARD AFTER TAU 36.
VERTICAL WIND SHEAR IS FAVORABLE FOR CONTINUED DEVELOPMENT UP TO TAU
48 WHEN COLD CONTINENTAL DRY AIR ADVECTING FROM THE SOUTHEAST WILL
BEGIN TO WEAKEN THE CORE OF THE SYSTEM. TC ERROL WILL REDUCE TO A
35-KT SYSTEM BY THE END OF THE FORECAST PERIOD.  NUMERICAL MODEL
GUIDANCE IS IN FAIR AGREEMENT WITH GFDN AND WBAR AS THE SOUTHERNMOST
OUTLIERS AND ECMF AS THE NORTHERNMOST OUTLIER. THIS FORECAST IS
SLIGHTLY TO THE NORTH OF CONSENSUS TO ACCOUNT FOR GFDN AND WBAR'S
INLIKELY TRACK INTO THE STEERING RIDGE. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 160000Z IS 16 FEET. NEXT WARNINGS AT 161500Z AND 170300Z.//
=========================================================================
WTXS31 PGTW 20110416 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   160600Z --- NEAR 11.5S 124.8E
     MOVEMENT PAST SIX HOURS - 315 DEGREES AT 01 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
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.5S 124.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   161800Z --- 10.9S 123.8E
   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
                            055 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 285 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   170600Z --- 10.6S 122.6E
   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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 270 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   171800Z --- 10.6S 121.5E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   180600Z --- 10.9S 120.1E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 255 DEG/ 07 KTS
    ---
   72 HRS, VALID AT:
   190600Z --- 11.6S 117.3E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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
                            075 NM SOUTHEAST QUADRANT
                            075 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 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:
   200600Z --- 12.1S 114.0E
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 265 DEG/ 12 KTS
    ---
   120 HRS, VALID AT:
   210600Z --- 12.6S 109.2E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
160900Z POSITION NEAR 11.3S 124.5E.
TROPICAL CYCLONE 21S, (ERROL), HAS TRACKED NORTHWEST AT 01 KNOTS
DURING THE PAST SIX HOURS. THE SLOW NORTHWESTWARD MOVEMENT OF THE
SYSTEM HAS KEPT IT UNDER THE SUB-TROPICAL RIDGE AXIS IN A REGION OF
FAVORABLE UPPER LEVEL CONDITIONS, WITH STRONG DIVERGENCE ALOFT AND
WEAK VERTICAL WIND SHEAR. THE TRACK IS ALSO KEEPING THE LOW LEVEL
CIRCULATION CENTER (LLCC) OVER FAVORABLY WARM WATERS (28-29 DEGREES
CELSIUS). THE CURRENT INTENSITY ESTIMATE IS BASED ON A 160127 ASCAT
PASS COMBINED WITH AN AVERAGE OF DVORAK ESTIMATES OF 35 KNOTS FROM
PGTW, 65 KNOTS FROM ADRM, AND 45 KNOTS FROM KNES. ANIMATED WATER
VAPOR IMAGERY SHOWS A WELL-DEVELOPED POLEWARD OUTFLOW CHANNEL,
ALTHOUGH SOME DRY AIR TO THE DISTANT SOUTHWEST IS BEGINNING TO
SUPPRESS OUTFLOW OVER THE SOUTHWESTERN QUADRANT. EARLIER VISUAL
IMAGERY ALSO SHOWS A MARKED ABSENCE OF CONVECTION OVER THE SOUTHERN
SEMI-CIRCLE OF THE SYSTEM, AS DO TOTAL PRECIPITABLE WATER LOOPS,
WHICH SHOW A WIDE EXPANSE OF DRY AIR OFF THE NORTHWEST COAST OF
AUSTRALIA. A CONTINUED WEST-NORTHWESTWARD MOVEMENT OF THE LOW LEVEL
CIRCULATION CENTER (LLCC) WILL ALLOW THE SYSTEM TO DEVELOP STEADILY
IN A MOIST ENVIRONMENT, WHEREAS ANY MOVEMENT TO THE SOUTH OF WEST
SHOULD RESULT IN RAPID WEAKENING. DYNAMIC AIDS SHOW A WIDE DISPARITY
IN TRACK. THE TRACK FORECAST FAVORS ECMWF AND STAYS NORTH OF
CONSENSUS, BETWEEN ECMWF AND CONSENSUS. THE INTENSITY FORECAST IS
BASED ON THE FAVORABLE CONDITIONS PROVIDED BY A TRACK UNDER THE SUB-
TROPICAL RIDGE AXIS, SLOWED SOMEWHAT BY LAND INTERACTION WITH THE
MARITIME CONTINENT AND THE EFFECTS OF DRY AIR AND INCREASING SHEAR
OVER THE SOUTHWESTERN QUADRANT. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
160600Z IS 17 FEET. NEXT WARNINGS AT 162100Z AND 170900Z.//
=========================================================================
WTXS31 PGTW 20110416 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   161200Z --- NEAR 11.5S 124.5E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 03 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 - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.5S 124.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   170000Z --- 11.1S 123.8E
   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 - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 275 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   171200Z --- 11.0S 122.9E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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 - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   180000Z --- 11.1S 121.8E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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 - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 250 DEG/ 08 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   181200Z --- 11.7S 120.3E
   MAX SUSTAINED WINDS - 070 KT, GUSTS 085 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 - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            070 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 250 DEG/ 08 KTS
    ---
   72 HRS, VALID AT:
   191200Z --- 12.7S 117.4E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 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 - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            070 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 265 DEG/ 09 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:
   201200Z --- 13.1S 113.8E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 270 DEG/ 10 KTS
    ---
   120 HRS, VALID AT:
   211200Z --- 13.2S 109.7E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
161500Z POSITION NEAR 11.4S 124.3E.
TROPICAL CYCLONE 21S, (ERROL), HAS TRACKED WESTWARD AT 03 KNOTS
DURING THE PAST SIX HOURS. ANIMATED INFRARED IMAGERY SHOWS
CONVECTION DEEPENING AND CONSOLIDATING AROUND THE LOW LEVEL
CIRCULATION CENTER (LLCC). THE LLCC EXISTS UNDER THE SUB-TROPICAL
RIDGE AXIS IN A REGION OF STRONG UPPER LEVEL DIVERGENCE AND WEAK
VERTICAL WIND SHEAR. A 160933Z 37GHZ WINDSAT PASS IN TANDEM WITH
INFRARED ANIMATION VERIFIES THAT CONVECTION IS REGENERATING OVER THE
SOUTHERN SEMI-CIRCLE, ALTHOUGH COVERAGE IS STILL RELATIVELY SPARSE.
TOTAL PRECIPITABLE WATER LOOPS SHOW A PRONOUNCED LACK OF MOISTURE
OVER THE NORTH AUSTRALIAN BASIN, TO THE SOUTH OF TC 21S. WATER VAPOR
ANIMATION INDICATES SYSTEM OUTFLOW IS STILL SUPPRESSED OVER THE
SOUTHWESTERN QUADRANT, BUT A WELL-DEVELOPED POLEWARD OUTFLOW CHANNEL
PERSISTS ON ITS SOUTHEASTERN FLANK. THE CURRENT INTENSITY ESTIMATE
IS BASED ON DVORAK ESTIMATES OF 45 KNOTS FROM PGTW AND KNES, 55
KNOTS FROM ADRM, A CIMSS AMSU ESTIMATE OF 56 KTS, AND A SATCON
ESTIMATE OF 59 KNOTS. DYNAMIC AIDS CONTINUE TO SHOW A WIDE DISPARITY
IN TRACK. THE TRACK FORECAST FAVORS ECMWF AND STAYS BETWEEN ECMWF
AND CONSENSUS, TO THE NORTH OF CONSENSUS. THE INTENSITY FORECAST IS
BASED ON THE FAVORABLE UPPER LEVEL CONDITIONS PROVIDED BY A TRACK
UNDER THE SUB-TROPICAL RIDGE AXIS, DAMPENED SOMEWHAT BY LAND
INTERACTION WITH THE LESSER SUNDA ISLANDS AND THE ANTICIPATED
EFFECTS OF DRY AIR AND SHEAR OVER THE SOUTHWESTERN QUADRANT.
NEXT WARNINGS AT 170300Z AND 171500Z.
=========================================================================
WTXS31 PGTW 20110416 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 006//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   161800Z --- NEAR 11.2S 124.4E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 02 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 - 070 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.2S 124.4E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   170600Z --- 10.9S 123.6E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 265 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   171800Z --- 11.0S 122.6E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 250 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   180600Z --- 11.4S 121.3E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 245 DEG/ 08 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   181800Z --- 12.1S 119.9E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 250 DEG/ 08 KTS
    ---
   72 HRS, VALID AT:
   191800Z --- 13.1S 116.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 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:
   201800Z --- 13.7S 113.6E
   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 120 HR POSIT: 260 DEG/ 10 KTS
    ---
   120 HRS, VALID AT:
   211800Z --- 14.5S 109.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
162100Z POSITION NEAR 11.1S 124.2E.
TROPICAL CYCLONE 21S, (ERROL), LOCATED APPROXIMATELY 390 NM
WEST-NORTHWEST OF DARWIN, AUSTRALIA, HAS REMAINED QUASI-STATIONARY
DURING THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE IMAGERY
SHOWS WEAKENING DEEP CONVECTION ASSOCIATED WITH A SMALL (< 200 NM)
LOW LEVEL CIRCULATION CENTER (LLCC). RECENT MICROWAVE IMAGERY
INDICATES A DECREASE IN CONVECTIVE ORGANIZATION WITHIN THE PAST 6
HOURS. THERE WAS LOW CONFIDENCE IN THE INITIAL POSITION, WHICH IS
BASED ON THE IR AND AN ILL-DEFINED LLCC IN A 161733Z AMSRE MICROWAVE
IMAGE. THE INITIAL INTENSITY IS HELD ON THE HIGHER END OF THE PGTW,
APRF, AND KNES DVORAK ESTIMATES RANGING FROM 35 TO 55 KNOTS DUE TO
THE SMALL SIZE OF THE SYSTEM. UPPER LEVEL ANALYSIS INDICATES TC
ERROL IS LOCATED IN AN AREA OF LOW VERTICAL WIND SHEAR AND GOOD
DIVERGENCE ALOFT. HOWEVER, AN UPPER LEVEL TROUGH DIGGING TO THE WEST
OF THE SYSTEM IS CAUSING SUBSIDENCE ON THIS SIDE. DRY AIR TO THE
WEST OF THE SYSTEM IS ALSO EVIDENT IN THE MICROWAVE IMAGERY. TC 21S
IS CURRENTLY TRACKING ALONG THE NORTHERN PERIPHERY OF A MID-LEVEL
STEERING RIDGE AND SHOULD CONTINUE TRACKING GENERALLY WEST-
NORTHWESTWARD TO WESTWARD THROUGHOUT THE FORECAST PERIOD. TC ERROL
IS EXPECTED TO MAINTAIN INTENSITY OVER THE NEXT 36 HOURS AND THEN
BEGIN TO WEAKEN DUE TO THE DRY AIR TO THE WEST AND INTERACTION WITH
LAND. BASED ON THIS, THE SYSTEM IS NOT EXPECTED TO INTENSIFY AS MUCH
AS PREVIOUSLY FORECAST. THE NUMERICAL MODELS ARE SOMEWHAT SPREAD BUT
IN FAIR AGREEMENT WITH THE WESTWARD TRACK EXCEPT FOR GFS, WHICH
CURVES THE SYSTEM BACK TO THE NORTHEAST. ADDITIONALLY, GFDN AND WBAR
PULL THE SYSTEM TOO FAR SOUTHWESTWARD. THE FORECAST TRACK IS FASTER
AND TO THE NORTH OF MODEL CONSENSUS TO ACCOUNT FOR THESE ERRORS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 161800Z IS 18 FEET. NEXT WARNINGS
AT 170900Z AND 172100Z.//
=========================================================================
WTXS31 PGTW 20110417 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   170000Z --- NEAR 11.1S 124.0E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 03 KTS
     POSITION ACCURATE TO WITHIN 060 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
                            060 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.1S 124.0E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   171200Z --- 11.0S 123.7E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 270 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   180000Z --- 11.0S 122.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 255 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   181200Z --- 11.2S 122.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 250 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   190000Z --- 11.6S 120.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            035 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 250 DEG/ 05 KTS
    ---
   72 HRS, VALID AT:
   200000Z --- 12.3S 118.8E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
170300Z POSITION NEAR 11.1S 123.9E.
TROPICAL CYCLONE 21S, (ERROL), LOCATED APPROXIMATELY 415 NM WEST OF
DARWIN, AUSTRALIA, HAS TRACKED WESTWARD AT 03 KNOTS OVER THE PAST SIX
HOURS. ANIMATED INFRARED IMAGERY SHOWS CONVECTIVE WRAP AROUND THE LOW
LEVEL CIRCULATION CENTER HAS LOOSENED AND HAS BECOME MORE FRAGMENTED.
THE SAME ANIMATION SHOWS OUTFLOW HAS REDUCED AS COOL DRY CONTINENTAL
AIR ADVECTS FROM THE SOUTHEAST. THIS IS ALSO EVIDENT IN
CIMSS TOTAL PRECIPITABLE WATER LOOP. THE INITIAL POSITION IS BASED ON
A 162143Z MICROWAVE IMAGE AND THE INITIAL INTENSITY IS SUPPORTED BY
DVORAK ESTIMATES FROM PGTW, KNES, AND APRF. THE SYSTEM IS JUST TO THE
NORTH OF A RIDGE AXIS IN A REGION OF WEAK VERTICAL WIND SHEAR (VWS).
TC 21S IS EXPECTED TO TURN ON A MORE WEST-SOUTHWESTWARD TRACK OVER
THE NEXT 12 HOURS AS THE STEERING SUBTROPICAL RIDGE CURRENTLY TO THE
SOUTHWEST REORIENTS AND BUILDS. INSPITE THE FAVORABLE VWS, THE DRY
AIR INTRUSION IS EXPECTED TO PERSIST ALONG ITS TRACK AND EVENTUALLY
ERODE THE SYSTEM TO 30 KNOTS BY TAU 72. THE AVAILABLE NUMERICAL
GUIDANCE IS IN LOOSE AGREEMENT WITH THIS FORECAST WHICH
IS INITIALLY TO THE SOUTH AND AHEAD OF CONSENSUS TO ACCOUNT FOR A
DRASTIC NORTHWARD AND SLOW GFS TRACK. AFTER TAU 24, THIS TRACK IS
MORE TO THE NORTH OF CONSENSUS TO OFFSET WBAR AND GFDN THAT ARE
UNREALISTICALLY TRACKING THE TC SOUTH INTO THE STEERING RIDGE.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170000Z IS 16 FEET. NEXT WARNINGS
AT 171500Z AND 180300Z.//
=========================================================================
WTXS31 PGTW 20110417 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 008//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   171200Z --- NEAR 10.1S 125.1E
     MOVEMENT PAST SIX HOURS - 315 DEGREES AT 01 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   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
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 10.1S 125.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   180000Z --- 10.1S 124.2E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 24 HR POSIT: 265 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   181200Z --- 10.2S 123.3E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 265 DEG/ 04 KTS
    ---
   36 HRS, VALID AT:
   190000Z --- 10.3S 122.4E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 255 DEG/ 04 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   191200Z --- 10.5S 121.6E
   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 72 HR POSIT: 265 DEG/ 04 KTS
    ---
   72 HRS, VALID AT:
   201200Z --- 10.7S 119.8E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
171500Z POSITION NEAR 10.1S 124.9E.
TROPICAL CYCLONE 21S, (ERROL),LOCATED APPROXIMATELY 360 NM WEST-
NORTHWEST OF DARWIN, AUSTRALIA, HAS TRACKED NORTHWESTWARD AT 01
KNOTS DURING THE PAST SIX HOURS. PRIOR TO ITS RECENT MOVEMENT, 21S
HAD REVERSED COURSE AND TRACKED  NORTHEAST FOR APPROXIMATELY 12
HOURS. ANIMATED INFRARED IMAGERY DURING THE COURSE CHANGE SHOWED THE
TWO MAJOR CLUSTERS OF CONVECTION ON EITHER SIDE OF THE LOW LEVEL
CIRCULATION CENTER (LLCC)CONVERGE AND PRODUCE A SUBSTANTIAL BURST OF
CONVECTION. SURFACE OBSERVATIONS FROM AL TARI AIRPORT (WATT) DURING
THE PROCESS REVEAL A SURGE OF SOUTHEASTERLY WINDS AS THE SYSTEM
CONSOLIDATED. A SERIES OF MICROWAVE IMAGES BETWEEN 170633Z AND
170903Z INDICATE POOR ORGANIZATION AND A LACK OF BANDING IN THE LOW
LEVEL CLOUD STRUCTURE BUT AN OVERALL INCREASE IN DEEP CONVECTION.
THE RETROGRADE TO THE NORTHEAST ACTED TO KEEP THE SYSTEM UNDER MORE
FAVORABLE UPPER LEVEL CONDITIONS, DIRECTLY UNDER THE SUB-TROPICAL
RIDGE AXIS IN A REGION OF HIGHLY DIFFLUENT FLOW AND WEAK VERTICAL
WIND SHEAR. RECENT ANIMATED WATER VAPOR IMAGERY SHOWS AN EXPANDING
FIELD OF DEEP MOISTURE AROUND THE SYSTEM, ALTHOUGH OUTFLOW REMAINS
SUPPRESSED OVER THE SOUTHWESTERN QUADRANT. ALSO IMPEDING INTENSITY
ARE SOUTHEASTERLIES FLOWING OFF-SHORE OF AUSTRALIA, WHICH ARE
PUMPING DRY AIR INTO THE BOUNDARY AND MID-LEVELS OF THE SYSTEM. AN
UPSTREAM SOUNDING FROM BROOME, AUSTRALIA SHOWED A PRONOUNCED
INVERSION NEAR 10KFT WITH VERY DRY AIR ABOVE THE INVERSION. UNTIL
THE RECENT SURGE IN CONVECTION, THE DRY AIR WAS CLEARLY WEAKENING
THE SYSTEM. THE CURRENT INTENSITY ESTIMATE IS BASED ON PERSISTENCE
AND A DVORAK ESTIMATE OF 35 KNOTS FROM PGTW AND A CIMSS SATCON
ESTIMATE OF 40 KNOTS. A MID-LEVEL STEERING RIDGE TO THE SOUTH OF 21S
WILL ACT TO KEEP IT OVER WARM WATERS AND UNDER FAVORABLE UPPER LEVEL
CONDITIONS, BUT THE FAVORABLE CONDITIONS WILL BE COUNTERED BY THE
WEAKENING INFLUENCES OF LAND INTERACTION WITH TIMOR AND DRY AIR
ENTRAINMENT INTO THE MID-LEVELS. ALTHOUGH DYNAMIC AIDS ARE COMING
INTO BETTER AGREEMENT REGARDING THE TRACK OF THE SYSTEM, THERE IS
STILL SIGNIFICANT DISPARITY THEM. THE FORECAST TRACK FAVORS THE
WESTWARD SOLUTION OF ECMWF, STAYING BETWEEN ECMWF AND CONSENSUS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171200Z IS 15 FEET. NEXT WARNINGS
AT 180300Z AND 181500Z.//
=========================================================================
WTXS31 PGTW 20110418 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 009//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) 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:
   180000Z --- NEAR 10.6S 123.5E
     MOVEMENT PAST SIX HOURS - 270 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
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 10.6S 123.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   181200Z --- 10.7S 123.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 260 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   190000Z --- 10.8S 122.4E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 36 HR POSIT: 270 DEG/ 03 KTS
    ---
   36 HRS, VALID AT:
   191200Z --- 10.8S 121.7E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
180300Z POSITION NEAR 10.6S 123.4E.
TROPICAL CYCLONE (TC) TWENTY-ONE (ERROL), LOCATED APPROXIMATELY
160 NM EAST OF SUMBA, INDONESIA, HAS REMAINED QUASI-STATIONARY OVER
THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
CONVECTION ASSOCIATED WITH THE SYSTEM HAS BECOME MORE FRAGMENTED AND
DISORGANIZED. WATER VAPOR IMAGERY SHOWS THE POLEWARD OUTFLOW THAT WAS
SUSTAINING THE TC IN THE PREVIOUS DAYS HAS DIMINISHED. ALSO, COLD DRY
CONTINENTAL AIR FROM THE SOUTHEAST CONTINUE TO ADVECT INTO THE CORE
OF THE SYSTEM. THE SAME ANIMATION SHOWS WESTERLY VERTICAL WIND SHEAR
(VWS) IS NOW SHIFTING THE CONVECTION TO THE EAST OF THE LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS BASED ON A
18/0002Z SSMIS MICROWAVE IMAGE DEPICTING A BROAD WARM NOTCH OVER THE
LLCC. THE INITIAL INTENSITY IS BASED ON DVORAK ESTIMATES OF 35 KNOTS
FROM PGTW AND KNES. TC ERROL IS EXPECTED TO SLOWLY WEAKEN AND
EVENTUALLY DISSIPATE BY TAU 36 DUE TO DRY AIR INTRUSION AND PROLONGED
VWS. THE AVAILABLE NUMERIC GUIDANCE IS IN FAIR AGREEMENT WITH GFS TO
THE RIGHT OF THE ENVELOPE AND WBAR AND GFDN TO THE LEFT. THIS TRACK
FORECAST IS SLIGHTLY TO THE NORTH OF CONSENSUS. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 180000Z IS 14 FEET. NEXT WARNINGS AT 181500Z AND
190300Z.//
=========================================================================
WTXS31 PGTW 20110418 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 21S (ERROL) WARNING NR 010//
RMKS/
1. TROPICAL CYCLONE 21S (ERROL) WARNING NR 010
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   181200Z --- NEAR 9.9S 123.1E
     MOVEMENT PAST SIX HOURS - 250 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 9.9S 123.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   190000Z --- 10.2S 122.4E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
181500Z POSITION NEAR 10.0S 122.9E.
TROPICAL CYCLONE 21S, (ERROL),LOCATED APPROXIMATELY 35 NM WEST-
NORTHWEST OF KUPANG, WEST TIMOR, HAS TRACKED WEST-SOUTHWESTWARD AT
06 KNOTS DURING THE PAST SIX HOURS. THE OVER-LAND TRACK OF THE
SYSTEM COUPLED WITH 15 KNOTS OF VERTICAL WIND SHEAR HAVE WEAKENED
THE SYSTEM SIGNIFICANTLY. OBSERVATIONS FROM THE NEAREST WEATHER
STATION (KUPANG, INDONESIA) SHOW LIGHT WINDS AND RISING PRESSURE.
ANIMATED INFRARED IMAGERY REVEALS SUBSTANTIAL WARMING OF THE CLOUD
TOPS AND A PRONOUNCED TREND TOWARD DISORGANIZATION. AN 181008Z SSMIS
37GHZ IMAGE INDICATES COMPLETE DISINTEGRATION OF THE LOW LEVEL CLOUD
BANDING AND THE 91GHZ IMAGE SHOWS ALMOST NO DEEP CONVECTION. THE
COMBINED EFFECTS OF 15 KNOTS OF VERTICAL WIND SHEAR, DRIER AIR
UPSTREAM, AND TOPOGRAPHICAL INTERFERENCE FROM THE LESSER SUNDAS WILL
PREVENT 21S FROM RE-INTENSIFYING AS IT TRACKS WESTWARD ALONG 10
DEGREES SOUTH LATITUDE. 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 181200Z IS 10 FEET.

Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.


Document: tropical_cyclone_errol_jtwc_advisories.htm
Updated: 17 June 2020
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