WTIO30 FMEE 020650
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 12/5/20232024
1.A TROPICAL DEPRESSION 5

2.A POSITION 2024/02/02 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 20.0 S / 68.5 E
(TWENTY    DECIMAL ZERO   DEGREES SOUTH AND
SIXTY EIGHT    DECIMAL FIVE   DEGREES EAST)
MOVEMENT: SOUTH-EAST 7 KT

3.A DVORAK ANALYSIS: 2.5/2.5/D 1.0/18 H

4.A CENTRAL PRESSURE: 1000 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW): NIL

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 185 SE: 185 SW: 370 NW: 0

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

1.B FORECASTS (WINDS RADII IN KM):
12H: 2024/02/02 18 UTC: 21.3 S / 69.8 E, VENT MAX= 030 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 220 SE: 220 SW: 335 NW: 0

24H: 2024/02/03 06 UTC: 23.5 S / 72.2 E, VENT MAX= 030 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 220 SE: 220 SW: 0 NW: 130

36H: 2024/02/03 18 UTC: 27.8 S / 75.2 E, VENT MAX= 035 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 465 SE: 595 SW: 280 NW: 260
34 KT NE: 185 SE: 185 SW: 0 NW: 0

48H: 2024/02/04 06 UTC: 34.0 S / 76.9 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 595 SE: 630 SW: 445 NW: 280
34 KT NE: 335 SE: 405 SW: 295 NW: 185

60H: 2024/02/04 18 UTC: 37.1 S / 78.4 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 665 SE: 650 SW: 465 NW: 370
34 KT NE: 260 SE: 335 SW: 335 NW: 220

72H: 2024/02/05 06 UTC: 39.5 S / 81.6 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 480 SE: 480 SW: 425 NW: 405
34 KT NE: 280 SE: 260 SW: 315 NW: 280

2.B LONGER-RANGE OUTLOOK:
NIL


2.C ADDITIONAL INFORMATION:
T=CI=2.5

SINCE THURSDAY NIGHT, INTENSE CONVECTIVE ACTIVITY HAS RESUMED NEAR
THE SYSTEM'S CENTER, PROBABLY LINKED TO ITS ACCELERATION IN THE SAME
DIRECTION AS THE WIND SHEAR AND ITS MOVEMENT OVER AN AREA OF HIGH
OCEANIC HEAT CONTENT. THE LATEST MICROWAVE PASSES SHOW A CLEAR
IMPROVEMENT IN THE SYSTEM'S INTERNAL STRUCTURE, PARTICULARLY THE
AMSR2 AT 2041Z. ONLY PARTIAL ASCAT PASSES SINCE YESTERDAY EVENING
SHOW THE PRESENCE OF WINDS REACHING AT LEAST 30KT, BUT IN THE ABSENCE
OF MORE COMPLETE OBJECTIVE DATA AND GIVEN THE IMPROVED CONFIGURATION,
WE CAN'T RULE OUT THE POSSIBILITY THAT GALE FORCE WINDS MAY HAVE BEEN
PRESENT AROUND 00UTC. SUBJECTIVE DVORAK ANALYSIS IN SHEARED PATTERN
OR BASED ON MET/PT GIVES A FT OF 2.0 AT 18UTC THEN 2.5 AT 00 AND
06UTC. THE SYSTEM IS ESTIMATED TO BE AT TROPICAL DEPRESSION STAGE,
BUT WITH CONSIDERABLE UNCERTAINTY AS TO ITS ACTUAL INTENSITY.
MOREOVER, THE POSITION OF THE CENTER IS UNCERTAIN AND ESTIMATED AT
06UTC AT THE WESTERN EDGE OF THE CONVECTIVE MASS, IN A CONTEXT OF
APPARENT INCREASE IN SHEAR EFFECTS.

THE SYSTEM IS MOVING SOUTHEASTWARD THEN SOUTH-SOUTHEASTWARD, STEARED
BY A MID-TROPOSPHERE TROUGH TO ITS WEST. IT WILL THEREFORE GRADUALLY
LEAVE THE TROPICAL DOMAIN AND EXIT TOWARDS THE SOUTHERN MID-LATITUDES
BY SUNDAY EVENING, PASSING CLOSE TO THE ISLAND OF AMSTERDAM.

IN TERMS OF INTENSITY, THERE IS CONSIDERABLE UNCERTAINTY IN THE SHORT
TERM AS TO THE EXACT POSITION OF THE CENTER, MORE OR LESS OFFSET TO
THE WEST OF THE CDO. ACCORDING TO MOST NUMERICAL MODELS, WIND SHEAR
IS SET TO INCREASE AND PROGRESSIVELY EXPOSE THE LOW-LEVEL CENTER BY
TONIGHT. THROUGH INTERACTION WITH THE UPPER TROUGH, BAROCLINIC
PROCESSES COULD THEN LEAD TO A REINTENSIFICATION FROM SATURDAY
ONWARDS, BUT WITH THE SYSTEM BECOMING ASYMMETRICAL AND UNDERGOING
EXTRATROPICAL TRANSITION, WITH A WIDENING OF ITS AREA OF STRONG
WINDS.

EXPECTED IMPACTS ON AMSTERDAM ISLAND :
- GALE FORCE WINDS (35-40KT LIKELY, TEMPORARILY 45KT POSSIBLE) FROM
SUNDAY 06UTC UNTIL MONDAY 06UTC.
- WAVE HEIGHTS OF 4 TO 6 METERS ON SUNDAY AND UNTIL MONDAY MORNING
(PEAK ON SUNDAY EVENING).=

WTIO30 FMEE 021230
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 13/5/20232024
1.A ZONE OF DISTURBED WEATHER 5

2.A POSITION 2024/02/02 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 20.4 S / 69.3 E
(TWENTY    DECIMAL FOUR   DEGREES SOUTH AND
SIXTY NINE    DECIMAL THREE   DEGREES EAST)
MOVEMENT: SOUTH-EAST 8 KT

3.A DVORAK ANALYSIS: 1.5/2.5/W 1.0/12 H

4.A CENTRAL PRESSURE: 1000 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW): NIL

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 280 SE: 335 SW: 480 NW: 0

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

1.B FORECASTS (WINDS RADII IN KM):
12H: 2024/02/03 00 UTC: 22.8 S / 71.4 E, VENT MAX= 030 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 280 SE: 335 SW: 390 NW: 0

24H: 2024/02/03 12 UTC: 26.9 S / 74.0 E, VENT MAX= 035 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 350 SE: 405 SW: 280 NW: 185
34 KT NE: 165 SE: 165 SW: 0 NW: 0

36H: 2024/02/04 00 UTC: 32.1 S / 76.5 E, VENT MAX= 040 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 520 SE: 630 SW: 370 NW: 260
34 KT NE: 280 SE: 295 SW: 260 NW: 165

48H: 2024/02/04 12 UTC: 36.1 S / 77.8 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 575 SE: 610 SW: 480 NW: 345
34 KT NE: 305 SE: 315 SW: 280 NW: 205

60H: 2024/02/05 00 UTC: 39.4 S / 80.3 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 665 SE: 650 SW: 445 NW: 370
34 KT NE: 295 SE: 390 SW: 315 NW: 205

72H: 2024/02/05 12 UTC: 41.5 S / 84.6 E, VENT MAX= 045 KT,
EXTRATROPICAL DEPRESSION
28 KT NE: 555 SE: 595 SW: 445 NW: 405
34 KT NE: 295 SE: 370 SW: 315 NW: 280

2.B LONGER-RANGE OUTLOOK:
NIL


2.C ADDITIONAL INFORMATION:
T=1.5 CI=2.5

AFTER ITS TEMPORARY INTENSIFICATION ON THURSDAY NIGHT, THE SYSTEM HAS
NOW CLEARLY BROKEN UP THIS FRIDAY BETWEEN 06 AND 12UTC. DUE TO
INCREASING WEST-NORTH-WESTERLY SHEAR AND MASSIVE DRY AIR ADVECTION
FROM THE WEST, DEEP CONVECTION IS NOW LOCATED MORE 100 NM EAST OF AN
EXPOSED AND ELONGATED LOW-LEVEL CENTER, BROKEN UP INTO SEVERAL SMALL
SECONDARY VORTICES. DUE TO INERTIA, THE INTENSITY IS LEFT AT 30KT AND
THE SYSTEM IS CLASSIFIED AS A ZONE OF DISTURBED WEATHER. ITS
DESTRUCTURATION AND ASYMMETRIZATION SEEM TO SHOW THAT IT IS BEGINNING
TO LOSE ITS FULLY TROPICAL CHARACTERISTICS.

THE SYSTEM IS MOVING SOUTHEASTWARD THEN SOUTH-SOUTHEASTWARD, STEARED
BY A MID-TROPOSPHERE TROUGH TO ITS SOUTH-WEST THEN WEST. IT WILL
THEREFORE GRADUALLY LEAVE THE TROPICAL DOMAIN AND EXIT TOWARDS THE
SOUTHERN MID-LATITUDES BY SUNDAY EVENING, PASSING CLOSE TO THE ISLAND
OF AMSTERDAM.

IN TERMS OF INTENSITY, INCREASING WIND SHEAR AND INTERACTION WITH AN
UPPER TROUGH SHOULD MAKE THE SYSTEM BECOME POST-TROPICAL OVERNIGHT,
THEN IT SHOULD INTENSIFY THROUGH BAROCLINIC PROCESSES FROM SATURDAY
ONWARDS WHILE BECOMING EXTRATROPICAL BY SUNDAY AND MONDAY, WITH WINDS
ABOVE GALE INTENSITY AND A WIDENING OF THE AREA OF STRONG WINDS.

EXPECTED IMPACTS ON AMSTERDAM ISLAND :
- GALE FORCE WINDS (35-40KT LIKELY, TEMPORARILY 45KT POSSIBLE) FROM
SUNDAY 06UTC UNTIL MONDAY 06UTC.
- WAVE HEIGHTS OF 4 TO 6 METERS ON SUNDAY AND UNTIL MONDAY MORNING
(PEAK ON SUNDAY EVENING).


LAST BULLETIN ISSUED BY RSMC LA REUNION ON THIS SYSTEM, UNLESS
RE-INTENSIFICATION. FURTHER INFORMATION ON THIS SYSTEM WILL BE
AVAILABLE IN THE DAILY BULLETIN ON TROPICAL WEATHER CONDITIONS OVER
THE SOUTHWEST INDIAN OCEAN ISSUED AT 12Z (AWIO20 FMEE).=