WTIO30 FMEE 181238
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 30/2/20232024
1.A SEVERE TROPICAL STORM 2 (BELAL)
2.A POSITION 2024/01/18 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 23.9 S / 66.1 E
(TWENTY THREE DECIMAL NINE DEGREES SOUTH AND
SIXTY SIX DECIMAL ONE DEGREES EAST)
MOVEMENT: EAST-SOUTH-EAST 5 KT
3.A DVORAK ANALYSIS: 4.0/4.0/D 1.0/12 H
4.A CENTRAL PRESSURE: 974 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT
RADIUS OF MAXIMUM WINDS (RMW): 41 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 295 SE: 740 SW: 480 NW: 240
34 KT NE: 185 SE: 220 SW: 185 NW: 150
48 KT NE: 0 SE: 110 SW: 90 NW: 0
64 KT NE: 0 SE: 0 SW: 0 NW: 0
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 1200 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP
1.B FORECASTS (WINDS RADII IN KM):
12H: 2024/01/19 00 UTC: 24.5 S / 66.6 E, VENT MAX= 050 KT, SEVERE TROPICAL STORM
28 KT NE: 240 SE: 555 SW: 370 NW: 185
34 KT NE: 150 SE: 185 SW: 150 NW: 0
48 KT NE: 75 SE: 100 SW: 95 NW: 0
24H: 2024/01/19 12 UTC: 24.9 S / 65.9 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 165 SE: 370 SW: 280 NW: 130
34 KT NE: 0 SE: 150 SW: 130 NW: 0
36H: 2024/01/20 00 UTC: 25.1 S / 64.6 E, VENT MAX= 025 KT, REMNANT LOW
48H: 2024/01/20 12 UTC: 25.2 S / 63.2 E, VENT MAX= 030 KT, REMNANT LOW
28 KT NE: 0 SE: 370 SW: 280 NW: 0
60H: 2024/01/21 00 UTC: 25.4 S / 61.6 E, VENT MAX= 030 KT, REMNANT LOW
28 KT NE: 0 SE: 425 SW: 335 NW: 0
72H: 2024/01/21 12 UTC: 25.3 S / 59.9 E, VENT MAX= 030 KT, DISSIPATING
28 KT NE: 0 SE: 480 SW: 405 NW: 0
2.B LONGER-RANGE OUTLOOK:
NIL
2.C ADDITIONAL INFORMATION:
T=CI=4.0-
OVER THE PAST 6 HOURS, CONVECTION HAS REMAINED INTENSE NEAR BELAL'S
CENTER, WHERE STRONG THUNDERSTORM ACTIVITY HAS BEEN DETECTED
AROUND 12UTC. A 0951Z AMSR2 MICROWAVE PASS SHOWS AN IRREGULAR
CONVECTIVE RING AT BOTH 37 AND 89GHZ, WITH A MERIDIAN TILT BETWEEN BOTH
IMAGES, TESTIFYING ABOUT ONGOING SOUTHERLY SHEAR NEAR 30 KT BETWEEN
850 AND 400HPA LEVELS. HOWEVER, CONVENTIONAL SATELLITE IMAGERY HAS SO
FAR FAILED TO REVEAL THE EFFECTS OF THIS SHEAR, BUT THIS COULD BE THE
CASE BY TONIGHT, PARTICULARLY IN VIEW OF THE 1220Z GPM MICROWAVE IMAGE
WHICH SHOWS DECOUPLING OF CONVECTION TO THE NORTHEAST OF THE
LOW-LEVEL CENTER. THE ESTIMATED INTENSITY AT 55KT BASED ON MET/PT AND
MICROWAVE AMSR2 DATA IS RATHER UNCERTAIN IN THE ABSENCE OF
COMPLEMENTARY OBJECTIVE DATA. AFTER EXAMINATION OF THE SHEARED
STRUCTURE ON THE LAST GPM, THE CENTER'S POSITION ESTIMATED AT 12UTC
SEEMS A LITTLE TOO FAR EAST COMPARED WITH REALITY AND WILL BE REVISED
AFTERHAND (THE SURFACE CENTER SEEMS NOT TO HAVE CROSSED THE 66TH EAST
MERIDIAN AFTER ALL).
BELAL'S TRACK SHOULD BEGIN A GRADUAL EASTWARD U-TURN THIS THURSDAY
NIGHT UNDER THE INFLUENCE OF CONTRADICTORY STEERING FLOWS DRIVEN BY
COMPETING RIDGES. THE EASTWARD MOVEMENT DRIVEN UP TO NOW BY THE
NEAR-EQUATORIAL RIDGE SHOULD GIVE WAY TO A WEST-SOUTHWESTWARD
MOVEMENT DRIVEN BY THE LOW TROPOSPHERE SUBTROPICAL RIDGE, ESPECIALLY
AS THE SYSTEM WEAKENS ON FRIDAY. THERE IS STILL SOME UNCERTAINTY AS TO
THE TIMING OF THIS U-TURN.
THE RECENT RENEWED INTENSIFICATION WAS TEMPORARY, AND A WEAKENING
TREND SHOULD RESUME ON THURSDAY NIGHT. INDEED, THE QUITE STRONG WIND
SHEAR SHOULD INJECT DRY AIR INTO THE SYSTEM'S CORE, AS HINTED BY RECENT
MICROWAVE DATA. A STEADY WEAKENING TREND IS THEREFORE FORECAST FROM
THURSDAY NIGHT INTO FRIDAY, WITH CONVECTION BEING EXPELLED
EAST/NORTH-EAST OF THE SYSTEM, LEADING BELAL TO WEAKEN TO REMNANT
LOW STAGE, WHICH SHOULD GRADUALLY FILL IN BY THIS WEEK-END.
BELAL DOES NOT POSE ANY THREAT TO INHABITED LANDS.

最后于 2024-01-18 22:15:00
被ygsj24编辑
,原因: