SIO: GIOVANNA - Post-Tropical

[HURAKAN]

weakening now

[Crostorm]

ZCZC 559
WTIO30 FMEE 200049
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 45/9/20112012
1.A SEVERE TROPICAL STORM 9 (GIOVANNA)
2.A POSITION 2012/02/20 AT 0000 UTC:
WITHIN 40 NM RADIUS OF POINT 26.0 S / 53.1 E
(TWENTY SIX DECIMAL ZERO DEGREES SOUTH AND FIFTY THREE DECIMAL ONE DEGREES EAST)
MOVEMENT : EAST 6 KT
3.A DVORAK ANALYSIS: 3.5/4.0/W 1.5/18 H
4.A CENTRAL PRESSURE: 988 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT
RADIUS OF MAXIMUM WINDS (RMW) :46 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 110 SE: 150 SW: 220 NW: 110
34 KT NE: 90 SE: 120 SW: 120 NW: 90
48 KT NE: 60 SE: 70 SW: 70 NW: 60
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 400 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/20 12 UTC: 25.2 S / 53.8 E, MAX WIND=045 KT, MODERATE TROPICAL STORM
24H: 2012/02/21 00 UTC: 24.5 S / 53.2 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
36H: 2012/02/21 12 UTC: 23.8 S / 52.3 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
48H: 2012/02/22 00 UTC: 22.8 S / 51.9 E, MAX WIND=020 KT, LOW
60H: 2012/02/22 12 UTC: 21.6 S / 51.6 E, MAX WIND=020 KT, LOW
72H: 2012/02/23 00 UTC: 20.5 S / 51.3 E, MAX WIND=020 KT, DISSIPATING
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T= 3.5 AND CI=4.0
IR IMAGERY SHOWS THAT GIOVANNA BECOMES TO UNDERGO A STRONG WESTERLY TO NORTH-WESTERLY WINDSHEAR. D
ESTRUCTURATION OF PATTERN IS FAST. LLCC IS DIFFICULT TO LOCALIZE (NO RECENT MW PICTURE) BUT SYSTEM
HAS LIKELY HIGHLY DECELERATE.
SYSTEM MIGHT KEEP ON TRACKING EAST-NORTHEASTWARD WITHIN THE NEXT HOURS BY CONTINUING TO WEAKEN RAP
IDLY. SO, ITS STEERING FLOW IS EXPECTED TO MOVE IN LOWER TROPOSPHERE. BEYOND, NWP MODELS ARE NOT I
N GOOD AGREEMENT LIKE ECMWF ENSEMBLE RUN. TWO OPTIONS ARE POSSIBLE. A SOUTH-SOUTHEASTWARD RECURVE
OR A NORTH-NORTHWESTWARD RECURVE. RSMC KEEPS NORTHWARD OPTION (RIDGE SITUATED IN THE WEST THEN SOU
TH-WEST OF THE SYSTEME).
ON THIS FORECAST TRACK, ENVIRONMENTAL CONDITIONS ARE VERY DEFAVOURABLE WITH A STRONG WESTERLY THEN
SOUTH-WESTERLY VERTICAL WIND SHEAR DUE TO AN UPPER TROPOSPHERIC TROUGH TRANSITING SOUTH-EAST OF M
ADAGASCAR.
THE RESIDUAL LOW IS FORECAST TO FILL UP ON WEDNESDAY, WITHIN A BROAD AREA OF LOW PRESSURE OVER THE
MASCARENE ISLANDS.
NNNN

[senorpepr]

WTIO22 FMEE 200707 CCA
OTHER INFORMATIONS:
GIOVANNA IS UNDERGOING A VIOLENT VERTICAL WIND SHEAR SO THE SYSTEM IS
WEAKENING VERY RAPIDLY.=

[HURAKAN]

WTIO30 FMEE 201247 CCA
***************CORRECTIVE**************
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 53/9/20112012
1.A FILLING UP 9 (EX-GIOVANNA)
2.A POSITION 2012/02/20 AT 1200 UTC:
WITHIN 10 NM RADIUS OF POINT 24.9 S / 53.0 E
(TWENTY FOUR DECIMAL NINE DEGREES SOUTH AND FIFTY THREE DECIMAL ZERO
DEGREES EAST)
MOVEMENT : NORTH 5 KT
3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: 1001 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: SE: 90 SW: 90 NW:
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 400 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/21 00 UTC: 23.2 S / 52.7 E, MAX WIND=020 KT, LOW
24H: 2012/02/21 12 UTC: 22.0 S / 52.5 E, MAX WIND=000 , DISSIPATING
36H: 2012/02/22 00 UTC: 20.8 S / 52.5 E, MAX WIND=000 , DISSIPATING
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
ON THE LAST CC SATELLITE IMAGERY THE LOW LEVEL CIRCULATION IS
COMPLETELY EXPOSED VERY FAR NORTHWEST OF THE CONVECTION.THE SYSTEM
HAS WEAKENED VERY RAPIDLY.
ITS STEERING FLOW IS NOW LOCATED IN LOWER TROPOSPHERE. THE TRACK OF
THE RESIDUAL LOW IS A NORTH-NORTHWESTWARD RECURVE DUE TO THE HIGH
SUBTROPICALES REBUILDING IN THE SOUTH OF THE SYSTEM.
ON THIS FORECAST TRACK, ENVIRONMENTAL CONDITIONS ARE VERY
DEFAVOURABLE WITH A STRONG WESTERLY THEN SOUTH-WESTERLY VERTICAL
WIND SHEAR DUE TO AN UPPER TROPOSPHERIC TROUGH TRANSITING SOUTH-EASTOF MADAGASCAR.
THE RESIDUAL LOW IS FORECAST TO FILL UP, WITHIN A BROAD AREA OF LOW
PRESSURE OVER THE MASCARENE ISLANDS.
THIS IS THE LAST WARNING ABOUT THIS SYSTEM UNLESS REINTENSIFICATION.

[HURAKAN]

GIOVANNA is no more

[Chacor]

Absolutely remarkable long-lived system. 53 warnings?!

What a beast at peak intensity too, and it weakened as fast as it strengthened...

[HurricaneBill]

Madagascar: Cyclone Giovanna struck with little warning

[Crostorm]

The first part of this video shows Tropical Cyclone Giovanna having a well developed eye near the coast of Madagascar. Cyclones of this intensity (Category 3 to 4) often cause severe damage. In this clip the colored areas represent higher, colder clouds, with the strongest winds in the pink/lilac areas.

The second part of the clip is a Meteosat-9 HRV loop that shows two eyewall replacement cycles in Tropical Cyclone Giovanna. These occur in intense tropical cyclones with winds greater than 185 km/h. When cyclones reach this intensity, and the eyewall contracts, outer rainbands may strengthen and organise into a ring of thunderstorms, an outer eyewall, that slowly moves inward and chokes the inner wall, weakening the cyclone. The outer wall then replaces the inner wall, increasing intensity again.

credit: EUMETSAT

source: http://www.eumetsat.int/Home/index.htm

[youtube]http://www.youtube.com/watch?v=GJx3SHspPuM[/youtube]

[HurricaneBill]

Death toll in Madagascar cyclone rises to 31