Mozambique Channel: ex-IZILDA - Tropical Disturbance

[HURAKAN]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 25 MAR 2009 Time : 140000 UTC
Lat : 23:43:26 S Lon : 42:21:47 E

CI# /Pressure/ Vmax
2.8 / 993.4mb/ 41.0kt

Final T# Adj T# Raw T#
(3hr avg)
2.8 3.2 5.2

Latitude bias adjustment to MSLP : +0.0mb

Estimated radius of max. wind based on IR : 15 km

Center Temp : -28.6C Cloud Region Temp : -62.5C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[KWT]

Well the raw number is very impressive indeed, and I suspect if it holds then we will see the T number rise pretty briskly in response, next 6hrs will see what happens.

Eye is becoming less defined as convection pops as Hurakan stated on the last page, to be expected really.

[HURAKAN]

[HURAKAN]

[KWT]

That looks like a tropical cyclone to me right now to be honest, probably as soon as it starts to move away from land it'll grow stronger in terms of convection. Seems to have a very nice inflow as well I note.

I'd put this at 65-70kts right now to be honest.

[HURAKAN]

25/1430 UTC 23.7S 42.3E T4.0/4.0 IZILDA -- Southwest Indian

Dvorak agrees.

[KWT]

Yep not all that surprising, I fully expect the strength to be bumped up in response to those rapidly rising Dvorak numbers

[HURAKAN]

NRL: 60 knots!

[HURAKAN]

043
WTIO30 FMEE 251810 RRA

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

0.A WARNING NUMBER : 7/11/20082009
1.A SEVERE TROPICAL STORM 11 (IZILDA)

2.A POSITION 2009/03/25 AT 1800 UTC :
23.7S / 42.5E
(TWENTY THREE DECIMAL SEVEN DEGREES SOUTH AND FORTY TWO DECIMAL FIVE
DEGREES EAST)
MOVEMENT : QUASI-STATIONARY

3.A DVORAK ANALYSIS : 4.0/4.0 /D
4.A CENTRAL PRESSURE : 978 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 55 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 200 SE: 130 SO: 340 NO: 200
50 KT NE: 030 SE: 030 SO: 030 NO: 030

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1006 HPA / 350 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2009/03/26 06 UTC: 23.8S/42.4E, MAX WIND=065KT, TROPICAL
CYCLONE.
24H: 2009/03/26 18 UTC: 23.7S/42.4E, MAX WIND=060KT, SEVERE TROP.
STORM.
36H: 2009/03/27 06 UTC: 23.3S/41.8E, MAX WIND=055KT, SEVERE TROP.
STORM.
48H: 2009/03/27 18 UTC: 22.9S/40.6E, MAX WIND=050KT, SEVERE TROP.
STORM.
60H: 2009/03/28 06 UTC: 22.7S/39.6E, MAX WIND=045KT, MODERATE TROP.
STORM
.
72H: 2009/03/28 18 UTC: 22.4S/38.6E, MAX WIND=040KT, MODERATE TROP.
STORM
..

2.B OTHER INFORMATIONS:
T=CI=4.0

[HURAKAN]

[HURAKAN]

WTXS31 PGTW 252100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 24S (IZILDA) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 24S (IZILDA) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
251800Z --- NEAR 23.8S 42.5E
MOVEMENT PAST SIX HOURS - 140 DEGREES AT 03 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
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 23.8S 42.5E
---
FORECASTS:
12 HRS, VALID AT:
260600Z --- 23.6S 42.6E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 305 DEG/ 03 KTS
---
24 HRS, VALID AT:
261800Z --- 23.2S 42.0E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 300 DEG/ 05 KTS
---
36 HRS, VALID AT:
270600Z --- 22.7S 41.1E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 295 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
271800Z --- 22.2S 39.9E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
---
REMARKS:
252100Z POSITION NEAR 23.8S 42.5E.
TROPICAL CYCLONE (TC) 24S (IZILDA), LOCATED APPROXIMATELY 385 NM
SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED SOUTHEASTWARD AT
03 KNOTS OVER THE PAST SIX HOURS. TC 24S HAS INTENSIFIED RAPIDLY
OVER THE LAST 12 HOURS WITH THE CURRENT INTENSITY ESTIMATE BASED ON
FIXES FROM PGTW AND FMEE. ANIMATED INFRARED IMAGERY SHOWS WELL
FORMED CONVECTIVE BANDS WRAPPING INTO A TIGHTLY FORMED BANDING EYE
FEATURE WITH A STRONG POLEWARD OUTFLOW CHANNEL. A 251727Z SSMI-S
IMAGE SHOWS A TIGHT SPIRAL OF BROKEN DEEP CONVECTION AROUND THE LOW
LEVEL CIRCULATION CENTER WITH A LARGE REGION OF DRY AIR TO THE
SOUTHWEST OF THE SYSTEM. TC 24S IS IN A WEAK STEERING ENVIRONMENT
AND OVER THE NEXT 12 HOURS, THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE
TO THE SOUTHWEST WILL BUILD AND PROVIDE THE STEERING INFLUENCE,
TURNING THE CYCLONE SLOWLY WESTWARD AND BACK INTO THE MOZAMBIQUE
CHANNEL. DRY AIR ENTRAINMENT AND INCREASED VERTICAL WIND SHEAR WILL
OFFSET THE STRONG POLEWARD OUTFLOW INITIATING A WEAKENING TREND
BEYOND TAU 12. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 251800Z IS 13
FEET. NEXT WARNINGS AT 260900Z AND 262100Z.

[HURAKAN]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 25 MAR 2009 Time : 183000 UTC
Lat : 23:48:08 S Lon : 42:29:55 E

CI# /Pressure/ Vmax
3.2 / 988.2mb/ 49.0kt

Final T# Adj T# Raw T#
(3hr avg)
3.2 3.6 5.4

Latitude bias adjustment to MSLP : +0.0mb

Estimated radius of max. wind based on IR : 13 km

Center Temp : -30.0C Cloud Region Temp : -65.3C

Scene Type : EYE

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[KWT]

Looks like it should become a TC before any weakening trend starts to set in, indeed it probably already is a tropical cyclone given the textbook look it has achieved, looks better then Jasper did at any time in its life and the raw 5.4 only helps to confirm this.

[Chacor]

WTIO30 FMEE 260025

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

0.A WARNING NUMBER : 8/11/20082009
1.A SEVERE TROPICAL STORM 11 (IZILDA)

2.A POSITION 2009/03/26 AT 0000 UTC :
23.6S / 43.0E
(TWENTY THREE DECIMAL SIX DEGREES SOUTH AND FORTY THREE DECIMAL ZERO
DEGREES EAST)
MOVEMENT : EAST 3 KT

3.A DVORAK ANALYSIS : 4.0/4.0 /D
4.A CENTRAL PRESSURE : 974 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 60 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 150 SE: 150 SO: 250 NO: 150
50 KT NE: 030 SE: 030 SO: 030 NO: 030

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1006 HPA / 350 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2009/03/26 12 UTC: 23.5S/42.5E, MAX WIND=055KT, SEVERE TROP. STORM.
24H: 2009/03/27 00 UTC: 23.2S/41.9E, MAX WIND=050KT, SEVERE TROP. STORM.
36H: 2009/03/27 12 UTC: 22.7S/40.8E, MAX WIND=045KT, MODERATE TROP. STORM.
48H: 2009/03/28 00 UTC: 22.4S/40.1E, MAX WIND=040KT, MODERATE TROP. STORM.
60H: 2009/03/28 12 UTC: 22.2S/39.5E, MAX WIND=035KT, MODERATE TROP. STORM.
72H: 2009/03/29 00 UTC: 22.2S/38.7E, MAX WIND=030KT, TROP. DEPRESSION.

2.B OTHER INFORMATIONS:
T=CI=4.0+.
NORTHWESTERLY VERTICAL WIND SHEAR HAS STOPPED DEVELOPPMENT OF THE
SYSTEM, THE EYE HAS DISAPEARED ON THE SATELLITE IMAGERY. A WEAK TILT IS
VISIBLE ON MICROWAVES DATA (CF TRMM 1818Z).
IZILDA HAS CLEARLY SLOWN DOWN ESATWARDSAND IS EXPECTED TO RECURVE
SOON WEST-NORTHWESTWARDS UNDER THE STEERING INFLUENCE OF THE
SUBTROPICAL HIGH PRESSURES REBUILDING IN ITS SOUTHWEST AND BECOMING THE MAIN
STEERING FLOW.

UPPER-LEVEL JET (WELL SHOWED ON INFRARED METEOSAT7 IMAGERY) EXISTING
IN THE WEST AND IN THE SOUTH OF THE SYSTEM IS EXPECTED TO BE A
LIMITATING FACTOR AS THE SYSTEM RECURVE WEST-NORTHWESTWARDS, THEN THE
STRENGTHENING NORTHERLY WINDSHEAR (BEYOND TAU24 TO 36) SHOULD WEAKEN THIS SYSTEM
IOF SMALL SIZE.=

[HURAKAN]

Not as impressive as before but NRL is going with 65 knots.

[Chacor]

Weakened a bit at 06z from MF.

[HURAKAN]

What a difference 22 hours make!

[HURAKAN]

WTXS31 PGTW 260900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 24S (IZILDA) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 24S (IZILDA) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
260600Z --- NEAR 23.7S 43.3E
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 05 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 - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
REPEAT POSIT: 23.7S 43.3E
---
FORECASTS:
12 HRS, VALID AT:
261800Z --- 23.8S 43.4E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 205 DEG/ 01 KTS
---
24 HRS, VALID AT:
270600Z --- 24.0S 43.3E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 280 DEG/ 03 KTS
---
36 HRS, VALID AT:
271800Z --- 23.9S 42.6E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 285 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
280600Z --- 23.7S 41.8E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
---
REMARKS:
260900Z POSITION NEAR 23.7S 43.3E.
TROPICAL CYCLONE TC) 24S (IZILDA) LOCATED APPROXIMATELY 350 NM
SOUTHWEST OF ANTANANARIVO, MADAGASCAR HAS TRACKED EASTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. CURRENT INTENSITY IS BASED ON
SATELLITE INTENSITY ESTIMATES RANGING FROM 45 TO 65 KNOTS FROM PGTW
AND FMEE. TC 24S IS FORECAST TO WEAKEN THROUGHOUT THE FORECAST
PERIOD AS IT INTERACTS WITH LAND ON ITS EASTERN PERIPHERY AND
INCREASING VERTICAL WINDSHEAR FROM AN APPROACHING UPPER LEVEL TROUGH
TO THE SOUTHWEST. THE VERTICAL WINDSHEAR WILL CAUSE DECOUPLING OF
THE DEEP CONVECTION FROM THE LOW LEVEL CIRCULATION CENTER (LLCC). AS
VERTICAL WINDSHEAR INCREASES, THE LLCC WILL BEGIN TO STEER ON AN
EXTENSION OF SUBTROPICAL RIDGING CENTERED TO THE WEST OVER SOUTH
AFRICA AND EXTENDING INTO THE SOUTHERN MOZAMBIQUE CHANNEL. THIS WILL
CAUSE THE WEAKENING LLCC TO TRACK TO THE WEST-NORTHWEST AND BACK
INTO THE MOZAMBIQUE CHANNEL. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
260600Z IS 14 FEET. NEXT WARNINGS AT 262100Z AND 270900Z.

[KWT]

The shear has picked up very strongly just as forecasted by the agencies, seems to have been a very good forecast indeed.

[Chacor]

WTIO30 FMEE 261211

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

0.A WARNING NUMBER : 10/11/20082009
1.A MODERATE TROPICAL STORM 11 (IZILDA)

2.A POSITION 2009/03/26 AT 1200 UTC :
23.8S / 42.3E
(TWENTY THREE DECIMAL EIGHT DEGREES SOUTH AND FORTY TWO DECIMAL THREE
DEGREES EAST)
MOVEMENT : WEST 4 KT

3.A DVORAK ANALYSIS : 2.5/3.0 /W 0.5/6 H
4.A CENTRAL PRESSURE : 993 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 040 SE: 180 SO: 180 NO: 040

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1009 HPA / 500 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: SHALLOW

1.B FORECASTS:
12H: 2009/03/27 00 UTC: 23.6S/41.6E, MAX WIND=030KT, TROP. DEPRESSION.
24H: 2009/03/27 12 UTC: 23.3S/40.9E, MAX WIND=025KT, TROP. DISTURBANCE.
36H: 2009/03/28 00 UTC: 23.0S/39.6E, MAX WIND=020KT, TROP. DISTURBANCE.
48H: 2009/03/28 12 UTC: 23.1S/38.4E, MAX WIND=015KT, FILLING UP.
60H: 2009/03/29 00 UTC: 23.2S/37.3E, MAX WIND=015KT, FILLING UP.
72H: 2009/03/29 12 UTC: 23.7S/36.4E, MAX WIND=015KT, FILLING UP.

2.B OTHER INFORMATIONS:
T=2.5- CI=3.0
INERTIA BETWEEN SYSTEM PATTERN AND TRUE WEAKENING IS LESS FOR SMALL
SIZES SYSTEMS (6H).
THE SYSTEM HAS DRASTICALLY AND QUICKLY WEAKENED WITHIN AN UNFAVORABLE
ENVIRONMENT. NORTHWESTERLY VERTICAL WINDSHEAR IS OBVIOUS ON THE
IMAGERY.
LLCC IS NOW FULLY EXPOSED WEST OF THE RESIDUAL CONVECTION, WHICH IS
EASTWARDS AWAY OVER THE SOUTHWESTERN PART OF MADAGASCAR. MICROWAVE
(AMSU 0631Z)
AND WATER VAPOR IMAGERIES SHOW A DRIER AIR INTRUSION IN THE WEST.
IZILDA HAS TRACKED ERRATICALLY BUT IS NOW TRACKING WESTWARDS UNDER
THE STEERING INFLUENCE OF THE SUBTROPICAL HIGH PRESSURES.

UPPER-LEVEL JET PRESENT IN THE SOUTHWEST OF THE SYSTEM SHOULD
CONTINUE TO BE A LIMITATING FACTOR. THEN THE STRENGTHENING NORTHERLY WINDSHEAR
(BEYOND TAU 24 TO 36) SHOULD WEAKEN THIS SMALL SIZE SYSTEM.=