SIO: IMELDA - Severe Tropical Storm

[supercane4867]

8.0S 73.5E

[cycloneye]

WTXS21 PGTW 051300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
155 NM EITHER SIDE OF A LINE FROM 11.2S 75.4E TO 12.3S 67.3E
WITHIN THE NEXT 06 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 051230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.3S 74.7E. THE SYSTEM IS MOVING WESTWARD AT 12 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 10.7S 78.1E,
IS NOW LOCATED NEAR 11.3S 74.7E, APPROXIMATELY 270 NM SOUTH-SOUTHEAST
OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
FORMATIVE CONVECTIVE BANDS HAVE FURTHER DEEPENED AND WRAPPED TIGHTER
INTO A WELL-DEFINED, ALBEIT PARTIALLY EXPOSED, LOW LEVEL CIRCULATION
CENTER (LLCC). A 050638Z SCATTEROMETRY PASS CLEARLY SHOWS A TIGHTER
AND MORE SYMMETRIC LLCC WITH 30-KNOT WIND BARBS FEEDING INTO IT FROM
THE WESTERN AND SOUTHERN QUADRANTS. UPPER LEVEL ANALYSIS INDICATES
THE VERTICAL WIND SHEAR HAS RELAXED AS THE CYCLONE IS NOW MOVING
WESTWARD AND IN-PHASE WITH THE UPPER LEVEL WIND FLOW. ADDITIONALLY,
WESTWARD AND EQUATORWARD OUTFLOW REMAIN ROBUST. THESE ARE EVIDENT ON
RECENT ANIMATED WATER VAPOR IMAGERY. ALONG-TRACK SEA SURFACE
TEMPERATURES REMAIN FAVORABLE (28 TO 29 DEGREES CELSIUS) FOR FURTHER
DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO
33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
061300Z. //
NNNN

[cycloneye]

WTXS31 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 001//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/051251Z APR 13//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
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:
060600Z --- NEAR 10.9S 72.6E
MOVEMENT PAST SIX HOURS - 285 DEGREES AT 04 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: 10.9S 72.6E
---
FORECASTS:
12 HRS, VALID AT:
061800Z --- 10.9S 71.3E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 08 KTS
---
24 HRS, VALID AT:
070600Z --- 11.1S 69.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 255 DEG/ 09 KTS
---
36 HRS, VALID AT:
071800Z --- 11.6S 68.0E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 260 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
080600Z --- 12.0S 65.9E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 260 DEG/ 10 KTS
---
72 HRS, VALID AT:
090600Z --- 12.5S 62.0E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 260 DEG/ 07 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
100600Z --- 13.0S 59.3E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 235 DEG/ 04 KTS
---
120 HRS, VALID AT:
110600Z --- 14.0S 57.9E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
060900Z POSITION NEAR 10.9S 72.3E.
TROPICAL DEPRESSION (TD) 21S, LOCATED APPROXIMATELY 220 NM SOUTH OF
DIEGO GARCIA, HAS TRACKED WEST-NORTHWESTWARD AT 04 KNOTS DURING THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN
ELONGATED AREA OF DEEP CONVECTION WITH FORMATIVE BANDING WRAPPING
INTO AN ILL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). A 060502Z
TRMM 37 GHZ IMAGE REVEALS THE ELONGATED NATURE OF THE LLCC AND
SUGGESTS THE POSSIBILITY OF MULTIPLE VORTICES. THE INITIAL POSITION
IS BASED ON THE AFOREMENTIONED TRMM IMAGE AND POSITION FIXES FROM
PGTW AND KNES WITH LOW CONFIDENCE DUE TO THE BROADNESS OF THE
CIRCULATION. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS BASED ON
DVORAK CURRENT INTENSITY ESTIMATES FROM PGTW AND KNES. UPPER LEVEL
ANALYSIS INDICATES TD 21S IS JUST EQUATORWARD OF THE SUBTROPICAL
RIDGE (STR) AXIS WITH GOOD RADIAL OUTFLOW BEGINNING TO DEVELOP, AS
INDICATED BY ANIMATED WATER VAPOR IMAGERY. CONVECTIVE ORGANIZATION
IS BEING HAMPERED BY MODERATE (20 KNOTS) VERTICAL WIND SHEAR (VWS).
SEA SURFACE TEMPERATURES ARE FAVORABLE AT 29 DEG CELSIUS. TD 21S
WILL CONTINUE TO TRACK WEST-SOUTHWESTARD UNDER THE INFLUENCE OF THE
DEEP LAYER STR TO THE SOUTH. AS VWS BECOMES MORE FAVORABLE, THE
SYSTEM IS FORECAST TO GRADUALLY INTENSIFY TO A PEAK OF 100 KNOTS BY
TAU 96. AFTER TAU 96, TD 21S IS EXPECTED TO SLOW AND DEFLECT
POLEWARD AS AN APPROACHING MID-LATITUDE TROUGH BEGINS TO BREAKDOWN
THE STR. THE AVAILABLE DYNAMICAL MODEL AND ENSEMBLE GUIDANCE IS IN
GOOD AGREEMENT WITH THIS FORECAST SCENARIO, HOWEVER, THE OVERALL
FORECAST CONFIDENCE IS LOW DUE TO THE DIFFICULTY IN ASSESSING THE
INITIAL POSITION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 060600Z IS 10
FEET. AT 040606 TROPICAL CYCLONE CENTER LOCATED 228 NM S OF
DIEGO_GARCIA.NEXT WARNINGS AT 062100Z AND 070900Z. THIS WARNING
SUPERSEDES AND CANCELS REF A, JOINT TYPHOON WRNCEN PEARL HARBOR HI
051251Z APR 13 TROPICAL CYCLONE FORMATION ALERT(WTXS21 PGTW 051300)//
NNNN

[cycloneye]

JTWC is up to 40kts.

WTXS31 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 21S (TWENTYONE) 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:
071800Z --- NEAR 11.2S 68.2E
MOVEMENT PAST SIX HOURS - 255 DEGREES AT 11 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 - 035 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 11.2S 68.2E
---
FORECASTS:
12 HRS, VALID AT:
080600Z --- 11.6S 66.0E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 11 KTS
---
24 HRS, VALID AT:
081800Z --- 11.8S 63.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 265 DEG/ 10 KTS
---
36 HRS, VALID AT:
090600Z --- 12.0S 61.8E
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 - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 245 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
091800Z --- 12.6S 60.5E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
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 - 065 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 215 DEG/ 03 KTS
---
72 HRS, VALID AT:
101800Z --- 13.5S 59.8E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 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
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 185 DEG/ 04 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
111800Z --- 15.0S 59.7E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 155 DEG/ 05 KTS
---
120 HRS, VALID AT:
121800Z --- 16.7S 60.5E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
072100Z POSITION NEAR 11.3S 67.7E.
TROPICAL CYCLONE (TC) 21S (TWENTYONE), LOCATED APPROXIMATELY 335 NM
SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 11
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC)
LOCATED EAST OF PERSISTENT DEEP CONVECTION. A 071543Z SSMIS 37 GHZ
IMAGE SHOWS GOOD LOWER-LEVEL BANDING STRUCTURE OVER THE WESTERN
SEMICIRCLE BUT VERY FRAGMENTED AND WEAK BANDS TO THE EAST. A 071740Z
ASCAT PASS DEPICTED 35-40 KNOT WINDS OVER THE WESTERN PORTION OF THE
LLCC WHICH ARE WRAPPING INTO THE CENTER. THE CURRENT POSITION IS
BASED ON THE AFOREMENTIONED IMAGERY WITH FAIR CONFIDENCE. THE
CURRENT INTENSITY IS BASED ON THE TIMELY ASCAT PASS. UPPER-LEVEL
ANALYSIS INDICATES TC 21S IS APPROXIMATELY FIVE DEGREES EQUATORWARD
OF THE SUBTROPICAL RIDGE (STR) AXIS. VERTICAL WIND SHEAR (VWS)
REMAINS MODERATE (15-20 KNOTS), CAUSING THE DEEP CONVECTION TO BE
SHEARED TO THE WEST. ANIMATED WATER VAPOR IMAGERY DEPICTS MODERATE
POLEWARD OUTFLOW; HOWEVER, EQUATORWARD OUTFLOW IS LIMITED DUE TO
TROUGHING. TC 21S WILL CONTINUE TO TRACK WEST-SOUTHWESTWARD THROUGH
TAU 48 UNDER THE INFLUENCE OF THE DEEP LAYERED STR TO THE SOUTH. A
GRADUAL DECREASE IN VWS AND FAIR OUTFLOW WILL ALLOW FOR
INTENSIFICATION. ADDITIONALLY, A POOL OF HIGHER OCEAN HEAT CONTENT
LOCATED ALONG THE FORECAST TRACK WILL AID IN THIS INTENSIFICATION.
AFTER TAU 72, A DEEP LAYER MID-LATITUDE TROUGH WILL MOVE IN FROM THE
WEST AND BEGIN TO REORIENT THE STR IN THE NORTH-SOUTH DIRECTION,
ALLOWING FOR TC 21S TO TURN POLEWARD. THE FORECAST CALLS FOR A PEAK
INTENSITY OF 95 KNOTS BY TAU 96. THOUGH DYNAMICAL MODEL GUIDANCE IS
IN GENERALLY GOOD AGREEMENT WITH THE POLEWARD DEFLECTION IN THE
EXTENDED FORECAST, THE TIMING AND SHARPNESS IN THE DEFLECTION ARE
STILL UNCLEAR. THIS IS FURTHER EVIDENCED BY INCREASING SPREAD NOTED
IN ENSEMBLE MODEL PRODUCTS. THERE IS HIGH CONFIDENCE IN THE THREE
DAY FORECAST, BUT LOW CONFIDENCE IN THE EXTENDED PORTION. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 071800Z IS 15 FEET. NEXT WARNINGS AT
080900Z AND 082100Z.//

[Extratropical94]

JTWC stays at 40kts, but the system is named Imelda by the local RSMC.

WTXS31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 21S (IMELDA) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 21S (IMELDA) 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:
080600Z --- NEAR 10.9S 65.2E
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 12 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 - 035 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 10.9S 65.2E
---
FORECASTS:
12 HRS, VALID AT:
081800Z --- 11.1S 63.0E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 10 KTS
---
24 HRS, VALID AT:
090600Z --- 11.2S 61.0E
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 - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 260 DEG/ 07 KTS
---
36 HRS, VALID AT:
091800Z --- 11.5S 59.6E
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 - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 250 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
100600Z --- 11.8S 58.8E
MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 195 DEG/ 03 KTS
---
72 HRS, VALID AT:
110600Z --- 13.1S 58.5E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 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 - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 170 DEG/ 04 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
120600Z --- 14.7S 58.8E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 165 DEG/ 04 KTS
---
120 HRS, VALID AT:
130600Z --- 16.4S 59.2E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
080900Z POSITION NEAR 11.0S 64.7E.
TROPICAL CYCLONE (TC) 21S (IMELDA), LOCATED APPROXIMATELY 490 NM
WEST-SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 12 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS SPIRAL BANDING WRAPPING INTO A CLOUD COVERED LOW-LEVEL
CIRCULATION CENTER (LLCC) THAT HAS BEEN SLOWLY CONSOLIDATING OVER
THE PAST TWELVE HOURS. A 080408Z TRMM 37 GHZ IMAGE REVEALS GOOD
LOWER-LEVEL BANDING STRUCTURE OVER THE WESTERN SEMICIRCLE, BUT
FRAGMENTED AND WEAK BANDS TO THE NORTHEAST. A 080532Z ASCAT PASS
INDICATES 35-40 KNOT WINDS OVER THE WESTERN PORTION OF THE LLCC. THE
CURRENT POSITION IS BASED ON THE AFOREMENTIONED IMAGERY WITH FAIR
CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT 40 KNOTS BASED ON
DVORAK ESTIMATES RANGING FROM 35 TO 45 KNOTS FROM PGTW, KNES AND
FMEE, AS WELL AS THE ASCAT PASS. UPPER-LEVEL ANALYSIS INDICATES TC
21S IS APPROXIMATELY FOUR DEGREES EQUATORWARD OF THE SUBTROPICAL
RIDGE (STR) AXIS. THE EASTERLY VERTICAL WIND SHEAR (VWS) HAS RELAXED
SLIGHTLY TO 10 TO 15 KNOTS, AS THE STORM MOTION IS IN PHASE WITH THE
SHEAR VECTOR. ANIMATED WATER VAPOR IMAGERY INDICATES OUTFLOW HAS
BECOME MORE RADIAL AND ROBUST, HOWEVER, THE EXTENT OF THE OUTFLOW IS
LIMITED. THE FORECAST PHILOSOPHY REMAINS UNCHANGED; TC 21S WILL
CONTINUE TO TRACK WEST-SOUTHWESTWARD THROUGH TAU 48 UNDER THE
INFLUENCE OF THE DEEP LAYERED STR TO THE SOUTH. A CONTINUED DECREASE
IN VWS AND FAIR OUTFLOW WILL ALLOW FOR INTENSIFICATION.
ADDITIONALLY, A POOL OF HIGHER OCEAN HEAT CONTENT LOCATED ALONG THE
FORECAST TRACK WILL AID IN THIS INTENSIFICATION. AFTER TAU 48, TC
21S IS EXPECTED TO SLOW AND TURN POLEWARD AS AN APPROACHING DEEP
LAYER MID-LATITUDE TROUGH WILL REORIENT THE STR IN THE NORTH-SOUTH
DIRECTION. THIS TROUGH WILL TEMPORARILY ENHANCE OUTFLOW, PROVIDING
FOR FURTHER INTENSIFICATION. THE FORECAST CALLS FOR A PEAK INTENSITY
OF 95 KNOTS BY TAU 72. ALTHOUGH DYNAMICAL MODEL GUIDANCE IS IN
GENERALLY GOOD AGREEMENT WITH THIS FORECAST SCENARIO, THERE IS
INCREASING SPREAD IN THE TIMING AND SHARPNESS OF THE POLEWARD
DEFLECTION. THIS TREND IS ALSO NOTED IN ENSEMBLE MODEL PRODUCTS.
BASED ON THIS INCREASED SPREAD, THERE IS LOW CONFIDENCE IN THE JTWC
FORECAST AFTER TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 080600Z IS
17 FEET. NEXT WARNINGS AT 082100Z AND 090900Z.//
NNNN

[HurricaneBill]

Ship near the center reported lots of wind, rain, and shoes.

[Meow]

It is now a severe tropical storm, so the title is incorrect.


A possible very intense tropical cyclone estimated by ECMWF.

[Extratropical94]

RSMC Reunion:

0.A WARNING NUMBER: 16/10/20122013
1.A SEVERE TROPICAL STORM 10 (IMELDA)
2.A POSITION 2013/04/09 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 11.6 S / 59.7 E
(ELEVEN DECIMAL SIX DEGREES SOUTH AND FIFTY NINE DECIMAL SEVEN
DEGREES EAST)
MOVEMENT : WEST 6 KT
3.A DVORAK ANALYSIS: 4.0/4.0/D 0.5/12 H
4.A CENTRAL PRESSURE: 973 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 60 KT
RADIUS OF MAXIMUM WINDS (RMW) :46 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 280 SE: 300 SW: 300 NW: 240
34 KT NE: 170 SE: 190 SW: 190 NW: 150
48 KT NE: 90 SE: 90 SW: 90 NW: 90
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP


JTWC:

WARNING POSITION:
091800Z --- NEAR 11.6S 59.5E
MOVEMENT PAST SIX HOURS - 260 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 030 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT

Both agencies are estimating it to be just below hurricane/cyclone strength and both are expecting it to reach that intensity very soon.