WTIO30 FMEE 311226
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 9/14/20242025
1.A SEVERE TROPICAL STORM 14 (COURTNEY)

2.A POSITION 2025/03/31 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 24.6 S / 88.8 E
(TWENTY FOUR    DECIMAL SIX   DEGREES SOUTH AND
EIGHTY EIGHT    DECIMAL EIGHT   DEGREES EAST)
MOVEMENT: SOUTH-SOUTH-EAST 8 KT

3.A DVORAK ANALYSIS: 2.5/3.5/W 0.5/6 H

4.A CENTRAL PRESSURE: 984 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT
RADIUS OF MAXIMUM WINDS (RMW): 54 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 280 SE: 325 SW: 230 NW: 215
34 KT NE: 150 SE: 220 SW: 185 NW: 95
48 KT NE: 95 SE: 110 SW: 80 NW: 55
64 KT NE: 0 SE: 0 SW: 0 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/04/01 00 UTC: 25.4 S / 88.7 E, VENT MAX= 045 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 325 SE: 345 SW: 250 NW: 0
34 KT NE: 0 SE: 195 SW: 150 NW: 0

24H: 2025/04/01 12 UTC: 26.0 S / 88.5 E, VENT MAX= 045 KT, REMNANT
LOW
28 KT NE: 0 SE: 295 SW: 260 NW: 0
34 KT NE: 0 SE: 155 SW: 140 NW: 0

36H: 2025/04/02 00 UTC: 26.3 S / 87.7 E, VENT MAX= 035 KT, REMNANT
LOW
28 KT NE: 0 SE: 230 SW: 260 NW: 0
34 KT NE: 0 SE: 120 SW: 120 NW: 0

48H: 2025/04/02 12 UTC: 26.1 S / 86.1 E, VENT MAX= 035 KT, REMNANT
LOW
28 KT NE: 0 SE: 230 SW: 230 NW: 0
34 KT NE: 0 SE: 0 SW: 95 NW: 0

60H: 2025/04/03 00 UTC: 25.5 S / 83.4 E, VENT MAX= 030 KT, FILLING UP
28 KT NE: 0 SE: 230 SW: 130 NW: 0

72H: 2025/04/03 12 UTC: 25.1 S / 80.2 E, VENT MAX= 025 KT, FILLING UP

2.B LONGER-RANGE OUTLOOK:
NIL


2.C ADDITIONAL INFORMATION:
T=2.5 CI=3.5

LITTLE CHANGE OVER THE LAST 6 HOURS: COURTNEY'S CLOUD PATTERN REMAINS
WELL SHEARED, WITH DEEP CONVECTION RELEGATED TO THE SOUTHEAST
QUADRANT OF THE SYSTEM, DETACHED QUITE FAR FROM THE LOW-LEVEL CENTER
(LLC). THE DEEP SHEAR ESTIMATED BY CIMSS IS NORTH-WESTERLY FOR 36KT,
WHICH IS CONSISTENT WITH THE LARGE-SCALE SITUATION THAT CURRENTLY
PLACES THE SYSTEM ON THE EASTERN FLANK OF AN UPPER TROUGH CIRCULATING
FURTHER WEST. THE PRESENCE OF CONVECTION STILL ALLOWS A SUBJECTIVE
DVORAK ANALYSIS, GIVING A CI OF 3.5 PER INERTIA.

COURTNEY'S TRACK CURVES SOUTH-SOUTHWEST UNDER THE INFLUENCE OF A
RIDGE TO THE NORTHEAST AND AN UPPER TROUGH TO THE SOUTHWEST AND
SOUTH. WITH THE PROGRESSIVE WEAKENING OF THE SYSTEM, THE STEERING
FLOW DROPS BACK INTO THE MID-TROPOSPHERE AND THEN INTO THE LOWER
LAYERS. BETWEEN MONDAY EVENING AND TUESDAY, COURTNEY SHOULD MOVE
SLOWLY WITHIN A BAROMETRIC COL AT 700HPA, THEN THE MOVEMENT SHOULD
ACCELERATE WESTWARDS FROM TUESDAY EVENING, AS THE REMNANT LOW IS
TAKEN UP IN THE TRADE WINDS ON THE NORTH FACE OF THE SUBTROPICAL LOW
LAYER. THE RSMC FORECAST IS BASED ON A COMPROMISE BETWEEN THE BEST
AVAILABLE GUIDANCE, WHOSE DISPERSION IS INCREASING FROM MONDAY
ONWARDS, INDUCING LOW CONFIDENCE IN THE SYSTEM'S TRACK BEYOND.

COURTNEY'S INTENSITY WILL CONTINUE TO GRADUALLY DECREASE AS A RESULT
OF INCREASINGLY STRONG NORTHWESTERLY WINDSHEAR ALONG THE UPPER
TROUGH, INJECTING DRY AIR OVER THE LOW LEVEL CENTER. IN ADDITION,
COURTNEY'S SOUTHWARD MOVEMENT MEANS THAT IT IS CIRCULATING OVER MUCH
COOLER SURFACE WATERS, WITH VIRTUALLY NO OCEAN HEAT POTENTIAL. FROM
MONDAY EVENING, IN AN INCREASINGLY BAROCLINIC ENVIRONMENT, COURTNEY
SHOULD LOSE ITS TROPICAL CHARACTERISTICS, EVOLVING INTO A
POST-TROPICAL SYSTEM AND THEN INTO A REMNANT LOW IN THE FORM OF A
VORTEX DEVOID OF DEEP CONVECTION. DRY AIR WILL SETTLE PERMANENTLY
OVER THE LLC, WITH NO POSSIBILITY OF REINTENSIFYING. GALE-FORCE
WINDS, THEN NEAR GALE FORCE WINDS, MAY PERSIST IN THE SOUTHERN
SEMICIRCLE DUE TO THE PRESSURE GRADIENT EFFECT UNTIL WEDNESDAY,
BEFORE THE SYSTEM DISSIPATES OVER THE FOLLOWING DAYS.

COURTNEY DOES NOT THREATEN ANY INHABITED LAND.=