SIO: Ex-CINDA - Tropical Depression: Discussion

[HURAKAN]

WTXS31 PGTW 170300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 001//
RMKS/
1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
170000Z --- NEAR 10.3S 67.0E
MOVEMENT PAST SIX HOURS - 250 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: 10.3S 67.0E
---
FORECASTS:
12 HRS, VALID AT:
171200Z --- 10.9S 65.8E
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
035 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 240 DEG/ 08 KTS
---
24 HRS, VALID AT:
180000Z --- 11.7S 64.4E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 245 DEG/ 09 KTS
---
36 HRS, VALID AT:
181200Z --- 12.5S 62.8E
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
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 255 DEG/ 09 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
190000Z --- 12.9S 61.1E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
---
REMARKS:
170300Z POSITION NEAR 10.4S 66.7E.
TROPICAL CYCLONE (TC) 04S (FOUR), LOCATED APPROXIMATELY 370 NM
WEST-SOUTHWEST OF DIEGO GARCIA HAS TRACKED WEST-SOUTHWESTWARD
OVER THE PAST 06 HOURS. ANIMATED INFRARED IMAGERY SHOWS DEEP
CONVECTION HAS DEVELOPED OVER A TIGHTLY WRAPPED LOW LEVEL
CIRCULATION CENTER (LLCC). TC 04S HAS UNDERGONE SIGNIFICANT
DEVELOPMENT OVER THE PAST 12 HOURS, WITH SATELLITE DVORAK
INTENSITY ESTIMATES REACHING 2.5/2.5 (PGTW AND FMEE) AND
2.0/2.0 (KNES). TC 04S IS FORECAST TO TRACK WEST-SOUTHWEST
THROUGH TAU 24 ALONG THE NORTHERN PERIPHERY OF THE SUBTROPICAL
RIDGE. AFTER TAU 24, THE TRACK WILL BECOME MORE WESTERLY AS
THE RIDGE ORIENTS ITSELF MORE EAST-WEST. INTENSIFICATION IS
EXPECTED TO BE SLOW DUE TO ONLY WEAK POLEWARD OUTFLOW, BUT
FAVORABLE VERTICAL WIND SHEAR. THIS WARNING SUPERSEDES AND
CANCELS REF A, NAVMARFCSTCEN 162121Z DEC 08 TROPICAL CYCLONE
FORMATION ALERT (WTXS21 PGTW 162130) MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 170000Z IS 9 FEET. NEXT WARNINGS AT 171500Z AND
180300Z.//

[Chacor]

WTIO30 FMEE 170648

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 6/4/20082009
1.A TROPICAL DEPRESSION 4

2.A POSITION 2008/12/17 AT 0600 UTC :
WITHIN 20 NM RADIUS OF POINT 10.3S / 66.5E
(TEN DECIMAL THREE DEGREES SOUTH AND SIXTY SIX DECIMAL FIVE DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 4 KT

3.A DVORAK ANALYSIS : 2.5/2.5 /D 0.5/24 H
4.A CENTRAL PRESSURE : 998 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 30 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 040 SE: 080 SO: 080 NO: 040

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1009 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS:
12H: 2008/12/17 18 UTC: 11.0S/65.6E, MAX WIND=030KT, TROP. DEPRESSION.
24H: 2008/12/18 06 UTC: 12.0S/64.5E, MAX WIND=035KT, MODERATE TROP. STORM
..
36H: 2008/12/18 18 UTC: 12.8S/63.5E, MAX WIND=035KT, MODERATE TROP. STORM
..
48H: 2008/12/19 06 UTC: 13.4S/62.2E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/19 18 UTC: 13.8S/61.0E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/20 06 UTC: 14.2S/60.0E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=CI=2.5.
THE DEEP CONVECTION HAS NOW PERSISTED FOR MORE THAN 12H ABOVE THE LOW
LEVEL CIRCULATION CENTRE ENABLING THE SYSTEM TO INTENSIFY TO TROPICAL
DEPRESSION STAGE.
THIS SYSTEM EVOLVES WITHIN A NEUTRAL TO SLIGHTLY FAVOURABLE ENVIRONMENT.
LOCATED BENEATH THE WESTERN PERIPHERY OF THE UPPER RIDGE IT BENEFITS FROM
WEAK VERTICAL WINDSHEAR, BUT UPPER OUTFLOW IS RESTRICTED TO A RATHER
WEAK POLEWARD CHANNEL.
THE SYSTEM IS EXPECTED TO KEEPS ON TRACKING WESTSOUTHWESTWARDS TO
SOUTHWESTWARDS. THERE IS HOWEVER SOME DESAGREEMENT BETWEEN THE DIFFERENT
NUMERICAL MODELS ABOUT THE SPEED OF MOVEMENT.
THE POTENTIAL FOR FURTHER INTENSIFICATION APPEARS LIMITED ALTHOUGH THERE
IS A WINDOW FOR SOME IMPROVEMENT WITHIN THE NEXT 24 HOURS BEFORE MODERATE
NORTHERLY SHEAR SETTLES AHEAD OF AN UPPER LEVEL TROUGH WEST OF THE
SYSTEM AND STARTS TO IMPINGE ON THE SYSTEM.
SYSTEM COULD HOWEVER REACH TEMPORARILY THE MINIMAL TROPICAL STORM STAGE.

[Chacor]

WTIO30 FMEE 171236

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 7/4/20082009
1.A TROPICAL DEPRESSION 4

2.A POSITION 2008/12/17 AT 1200 UTC :
WITHIN 20 NM RADIUS OF POINT 10.5S / 66.7E
(TEN DECIMAL FIVE DEGREES SOUTH AND SIXTY SIX DECIMAL SEVEN DEGREES EAST)
MOVEMENT : QUASI-STATIONARY

3.A DVORAK ANALYSIS : 2.5/2.5 /D 0.5/24 H
4.A CENTRAL PRESSURE : 998 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 30 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 040 SE: 080 SO: 080 NO: 040

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 1000 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS:
12H: 2008/12/18 00 UTC: 11.2S/66.0E, MAX WIND=035KT, MODERATE TROP. STORM
..
24H: 2008/12/18 12 UTC: 12.4S/64.8E, MAX WIND=035KT, MODERATE TROP. STORM
..
36H: 2008/12/19 00 UTC: 13.2S/63.8E, MAX WIND=030KT, TROP. DEPRESSION.
48H: 2008/12/19 12 UTC: 13.9S/62.5E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/20 00 UTC: 14.3S/61.3E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/20 12 UTC: 14.8S/60.0E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=CI=2.5. VERY LITTLE CHANGE DURING PAST HOURS WITH NO SIGNIFICANT
EVOLUTION IN TERMS OF INTENSITY AND A SYSTEM WHICH HAS STALLED ALMOST ON
SPOT.
THIS SYSTEM EVOLVES WITHIN AN ENVIRONMENT WHICH IS NEUTRAL TO SLIGHTLY
FAVOURABLE FOR THE MOMENT. LOCATED BENEATH THE WESTERN PERIPHERY OF THE
UPPER RIDGE IT BENEFITS FROM WEAK VERTICAL WINDSHEAR, WHILE THE UPPER
OUTFLOW IS RESTRICTED TO A MODERATELY POTENT POLEWARD CHANNEL (AHEAD OF
AN UPPER TROUGH
TO THE WEST).
WHILE THERE IS A CONSENSUS AMONG THE DIFFERENT NUMERICAL MODELS FOR A
GENERAL SOUTHWESTWARD MOTION OF THE SYSTEM THEY DISAGREE NOTICEABLY ABOUT
THE FUTURE SPEED OF MOVEMENT.
THE POTENTIAL FOR FURTHER INTENSIFICATION APPEARS LIMITED ALTHOUGH THERE
IS A WINDOW FOR SOME MARGINAL IMPROVEMENT WITHIN THE NEXT 12 TO 24 HOURS
BEFORE NORTHERLY TO NORTHWESTERLY WINDS START TO STRENGTHEN AND TO
IMPINGE ON THE CLOUD SYSTEM AFFECTING IT THROUGH INCREASING VERTICAL WIND
SHEAR.

[HURAKAN]

NRL: 40 knots

[Alacane2]

Moderate Tropical Storm Cinda

WTIO30 FMEE 180046

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 9/4/20082009
1.A MODERATE TROPICAL STORM 4

2.A POSITION 2008/12/18 AT 0000 UTC :
WITHIN 30 NM RADIUS OF POINT 11.3S / 66.9E
(ELEVEN DECIMAL THREE DEGREES SOUTH AND SIXTY SIX DECIMAL NINE DEGREES
EAST)
MOVEMENT : SOUTH 4 KT

3.A DVORAK ANALYSIS : 3.0/3.0 /D 0.5/12 H
4.A CENTRAL PRESSURE : 994 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 35 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 060 SE: 120 SO: 120 NO: 060

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2008/12/18 12 UTC: 12.8S/66.6E, MAX WIND=040KT, MODERATE TROP. STORM
..
24H: 2008/12/19 00 UTC: 13.4S/65.7E, MAX WIND=035KT, MODERATE TROP. STORM
..
36H: 2008/12/19 12 UTC: 13.9S/64.8E, MAX WIND=035KT, MODERATE TROP. STORM
..
48H: 2008/12/20 00 UTC: 14.1S/63.6E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/20 12 UTC: 14.6S/62.2E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/21 00 UTC: 15.2S/61.1E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=CI=3.0-

DEEP CONVECTION AND COLD CLOUD TOP HAS MAINTAINED DURING THE WHOLE NIGHT
NEAR THE LLCC.

SO INTENSITY HAS BEEN UPGRADED TO 35 KT AND THE SYSTEM HAS BEEN NAMED
'CINDA' BY THE NATIONAL WEATHER SERVICES OF MAURITIUS AT 00H00 UTC.

THE ENVIRONMENT HAS STILL NOT CHANGED: IT IS SLIGHTLY FAVOURABLE .
LOCATED BENEATH THE WESTERN PERIPHERY OF THE UPPER RIDGE IT BENEFITS FROM
WEAK VERTICAL WINDSHEAR, WHILE THE UPPER OUTFLOW IS RESTRICTED TO A
MODERATELY POTENT POLEWARD CHANNEL (AHEAD OF AN UPPER TROUGH TO THE WEST)
..
IT IS STILL FORECAST TO BECOME LESS AND LESS FAVORABLE WITH THE
STRENGHENING OF NORTHERN TO NORTHWESTERN WINDS AND THE LOSS OF THE UPPER
LEVEL RIDGE.

ABOUT THE FORCAST TRACK, IT SEEMS THAT CURRENT STEERING FLOW ARE FROM THE
MID-LEVEL (700/500 HPA) WHERE THEY ARE SOMEWHAT WEAK AS THE SYSTEM IS
LOCATED ON THE WESTERN EDGE OF A MID LEVEL RIDGE (IT IS EXPLAINING THE
CURRENT SOUTHWARDS MOTION). AS THE SYSTEM SHOULD PROGRESSIVELY WEAKEN, IT
SHOULD BE S
TEERED BY A MORE LOW LEVEL STEERING FLOW WITH A WESTSOUTHWESTWARDS MOTION
TOMORROW.

[Chacor]

Now Moderate Tropical Storm Cinda.

WTIO30 FMEE 180046

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 9/4/20082009
1.A MODERATE TROPICAL STORM 4

2.A POSITION 2008/12/18 AT 0000 UTC :
WITHIN 30 NM RADIUS OF POINT 11.3S / 66.9E
(ELEVEN DECIMAL THREE DEGREES SOUTH AND SIXTY SIX DECIMAL NINE DEGREES
EAST)
MOVEMENT : SOUTH 4 KT

3.A DVORAK ANALYSIS : 3.0/3.0 /D 0.5/12 H
4.A CENTRAL PRESSURE : 994 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 35 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 060 SE: 120 SO: 120 NO: 060

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2008/12/18 12 UTC: 12.8S/66.6E, MAX WIND=040KT, MODERATE TROP. STORM
..
24H: 2008/12/19 00 UTC: 13.4S/65.7E, MAX WIND=035KT, MODERATE TROP. STORM
..
36H: 2008/12/19 12 UTC: 13.9S/64.8E, MAX WIND=035KT, MODERATE TROP. STORM
..
48H: 2008/12/20 00 UTC: 14.1S/63.6E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/20 12 UTC: 14.6S/62.2E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/21 00 UTC: 15.2S/61.1E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=CI=3.0-

DEEP CONVECTION AND COLD CLOUD TOP HAS MAINTAINED DURING THE WHOLE NIGHT
NEAR THE LLCC.

SO INTENSITY HAS BEEN UPGRADED TO 35 KT AND THE SYSTEM HAS BEEN NAMED
'CINDA' BY THE NATIONAL WEATHER SERVICES OF MAURITIUS AT 00H00 UTC.

THE ENVIRONMENT HAS STILL NOT CHANGED: IT IS SLIGHTLY FAVOURABLE .
LOCATED BENEATH THE WESTERN PERIPHERY OF THE UPPER RIDGE IT BENEFITS FROM
WEAK VERTICAL WINDSHEAR, WHILE THE UPPER OUTFLOW IS RESTRICTED TO A
MODERATELY POTENT POLEWARD CHANNEL (AHEAD OF AN UPPER TROUGH TO THE WEST)
..
IT IS STILL FORECAST TO BECOME LESS AND LESS FAVORABLE WITH THE
STRENGHENING OF NORTHERN TO NORTHWESTERN WINDS AND THE LOSS OF THE UPPER
LEVEL RIDGE.

ABOUT THE FORCAST TRACK, IT SEEMS THAT CURRENT STEERING FLOW ARE FROM THE
MID-LEVEL (700/500 HPA) WHERE THEY ARE SOMEWHAT WEAK AS THE SYSTEM IS
LOCATED ON THE WESTERN EDGE OF A MID LEVEL RIDGE (IT IS EXPLAINING THE
CURRENT SOUTHWARDS MOTION). AS THE SYSTEM SHOULD PROGRESSIVELY WEAKEN, IT
SHOULD BE STEERED BY A MORE LOW LEVEL STEERING FLOW WITH A WESTSOUTHWESTWARDS MOTION
TOMORROW.

[HURAKAN]

50 knots.

[HURAKAN]

[Chacor]

Upgraded to Severe TS at 0600:

WTIO30 FMEE 180627

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 10/4/20082009
1.A SEVERE TROPICAL STORM 4 (CINDA)

2.A POSITION 2008/12/18 AT 0600 UTC :
12.2S / 66.8E
(TWELVE DECIMAL TWO DEGREES SOUTH AND SIXTY SIX DECIMAL EIGHT DEGREES
EAST)
MOVEMENT : SOUTH 5 KT

3.A DVORAK ANALYSIS : 3.5/3.5 /D 0.5/6 H
4.A CENTRAL PRESSURE : 985 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT
RADIUS OF MAXIMUM WINDS (RMW) : 20 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 090 SE: 150 SO: 150 NO: 090
50 KT NE: 040 SE: 040 SO: 040 NO: 040

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1007 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2008/12/18 18 UTC: 13.2S/66.3E, MAX WIND=050KT, SEVERE TROP. STORM.
24H: 2008/12/19 06 UTC: 14.0S/65.4E, MAX WIND=040KT, MODERATE TROP. STORM
..
36H: 2008/12/19 18 UTC: 14.3S/64.2E, MAX WIND=035KT, MODERATE TROP. STORM
..
48H: 2008/12/20 06 UTC: 14.6S/63.0E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/20 18 UTC: 15.2S/61.8E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/21 06 UTC: 15.8S/61.0E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
SATELLITE IMAGERY ANALYSIS LEADS TO T=CI=3.5+.
HOWEVER 85 GHZ MICROWAVE AND IR /VIS IMAGERY ARE MUCH MORE IMPRESSIVE
THAN 37 GHZ MICROWAVE IMAGERY. 85 GHZ IMAGERY (F17/0052Z, F15/0156Z,
F16/0325Z) ACTUALLY DISPLAYS A RATHER WELL DEFINED EYE, BUT ON THE 37 GHZ
THIS EYE IS ERODED ON THE NORTHERN EDGE. MOREOVER THESE IMAGERIES SHOW A
TILT BETWEEN THE LOW LEVEL AND THE UPPER LEVEL CENTRE. THIS SHOWS THE SYSTEM IS
UNDERGOING A NORTHERLY CONSTRAINT.

THE ENVIRONMENT REMAINS HOWEVER SLIGHTLY FAVOURABLE. LOCATED BENEATH THE
WESTERN PERIPHERY OF THE UPPER LEVEL RIDGE, THE SYSTEM BENEFITS FROM
STILL RATHER WEAK VERTICAL WINDSHEAR, WHILE THE UPPER OUTFLOW IS
RESTRICTED TO A MODERATELY POTENT POLEWARD CHANNEL (AHEAD OF AN UPPER
TROUGH TO THE WEST).
THIS ENVIRONMENT IS STILL FORECAST TO BECOME LESS AND LESS FAVORABLE WITH
THE STRENGTHENING OF NORTHERN TO NORTHWESTERN WINDS AND THE LOSS OF THE
UPPER LEVEL RIDGE.

ABOUT THE FORCAST TRACK, IT SEEMS THAT CURRENT STEERING FLOW ARE FROM THE
MID-LEVEL (700/500 HPA)- WHERE THEY ARE SOMEWHAT WEAK - AS THE SYSTEM IS
LOCATED ON THE WESTERN EDGE OF A MID LEVEL RIDGE (THIS EXPLAINS THE
CURRENT SOUTHWARDS MOTION). AS THE SYSTEM SHOULD GRADUALLY WEAKEN, IT
SHOULD BE STEERED BY A MORE LOW LEVEL STEERING FLOW AND THEN TRACK WESTSOUTHWESTWARDS.

[CrazyC83]

Warm water doesn't extend out very far in the southern Indian Ocean yet...

[Chacor]

Down to MTS.

[Chacor]

WTIO30 FMEE 191206

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 15/4/20082009
1.A MODERATE TROPICAL STORM 4 (CINDA)

2.A POSITION 2008/12/19 AT 1200 UTC :
13.7S / 64.9E
(THIRTEEN DECIMAL SEVEN DEGREES SOUTH AND SIXTY FOUR DECIMAL NINE
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 5 KT

3.A DVORAK ANALYSIS : 3.0/3.0 /S 0.0/24 H
4.A CENTRAL PRESSURE : 990 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT
RADIUS OF MAXIMUM WINDS (RMW) : 25 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 060 SE: 230 SO: 180 NO: 060

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2008/12/20 00 UTC: 14.3S/63.4E, MAX WIND=040KT, MODERATE TROP. STORM.
24H: 2008/12/20 12 UTC: 14.8S/62.3E, MAX WIND=040KT, MODERATE TROP. STORM.
36H: 2008/12/21 00 UTC: 15.4S/61.0E, MAX WIND=035KT, MODERATE TROP. STORM.
48H: 2008/12/21 12 UTC: 15.8S/60.4E, MAX WIND=030KT, TROP. DEPRESSION.
60H: 2008/12/22 00 UTC: 16.2S/60.1E, MAX WIND=030KT, TROP. DEPRESSION.
72H: 2008/12/22 12 UTC: 16.7S/59.9E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=3.0-, CI=3.0
NORTHERLY VERTICAL WINDSHEAR STILL EXISTS BUT HAS WEAKENED AS THE
UPPER LEVEL TROUGH HAS MOVED AWAY NORTHWARDS.
A NEW CLUSTER OF DEEP CONVECTIVE ACTIVITY HAS DEVELOP CLOSER TO THE
CENTER.
CINDA HAS TEMPORARELY STOPPED TO WEAKEN, THE INTENSITY REMAINS
STATIONARY.
LOW LEVEL EQUATORWARD INFLOW IS NOT ESTABLISHED AND MOISTURE SUPPLY
IS NOT SUFFICIENT.
THE SYSTEM IS NOW STEERED BY A THE LOW LEVELS STEERING FLOWS AND
TRACKS SOUTHWESTWARDS.
QUITE GOOD AGREEMENT OF THE AVALAIBLE DYNAMIC FORECAST AIDS UNTIL TAU
36, BUT DIVERGENCE BEYOND.
WINDS EXTENSION HAS BEEN RECALIBRATED THANKS TO 19/0137Z QUIKSCAT
SWATH.=

[Chacor]

Downgraded to TD 4 (ex-Cinda).