SIO: GAEL - Severe Tropical Storm - Discussion

[HURAKAN]

350
WTIO30 FMEE 100620

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

0.A WARNING NUMBER : 34/8/20082009
1.A EXTRATROPICAL DEPRESSION 8 (EX-GAEL)

2.A POSITION 2009/02/10 AT 0600 UTC :
WITHIN 20 NM RADIUS OF POINT 32.2S / 61.9E
(THIRTY TWO DECIMAL TWO DEGREES SOUTH AND SIXTY ONE DECIMAL NINE DEGREES
EAST)
MOVEMENT : EAST-SOUTH-EAST 13 KT

3.A DVORAK ANALYSIS : /W
4.A CENTRAL PRESSURE : 980 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 55 KT
RADIUS OF MAXIMUM WINDS (RMW) : 150 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 500 SE: 550 SO: 550 NO: 500
50 KT NE: 210 SE: 210 SO: 200 NO: 150

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1013 HPA / 1500 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS:
12H: 2009/02/10 18 UTC: 32.7S/63.5E, MAX WIND=050KT, EXTRATROPICAL.
24H: 2009/02/11 06 UTC: 33.4S/64.8E, MAX WIND=050KT, EXTRATROPICAL.
36H: 2009/02/11 18 UTC: 34.7S/66.2E, MAX WIND=040KT, EXTRATROPICAL.
48H: 2009/02/12 06 UTC: 37.1S/68.2E, MAX WIND=030KT, EXTRATROPICAL.
60H: 2009/02/12 18 UTC: 41.0S/72.2E, MAX WIND=020KT, DISSIPATING.


2.B OTHER INFORMATIONS:
FIX EXTRAPOLATED FROM THE QUICKSCAT PASS AT 02:08Z AND FROM EARLIER
VISIBLE IMAGERY.

CE,TRAL PRESSURE IS ESTIMATED FROM SURFACE DATA OF BUOY 17661 LOCATED
VERY CLOSE TO THE CENTER AROUND 23:00Z.

COMPARISON OF THE TWO LATEST QUICKSCAT PASS SHOW THAT GAEL HAS MADE ITS
EXTRATROPICAL TRANSITION (LARGE AREA OF LIGHT WINDS NEAR THE CENTER AND
WIDER RADIUS OF MAX WINDS)

IT IS EXPECTED TO TRACK SLOWLIER SOUTHEASTWARDS DURING THE NEXT 36 HEURES
, IN RELATION WITH THE SUBTROPICAL HIGH PRESSURES IN THE SOUTH OF THE
SYSTEM.

THURSDAY EVENING, THE RESIDUAL CIRCULATION OF GAEL SHOULD MERGE WITHIN A
POLAR TROUGH THAT SHOULD COME FROM THE SOUTHWEST.

LAST WARNINGS ON THIS SYSTEM. PLEASE REFER TO THE GMDSS BULLETINS FQIO20
FOR FURTHER DETAILS.