t02436

JTWC提升評級到Medium

t02436

MFR昨天18Z編號熱帶擾動一號
今天06Z升格熱帶低壓，預測24小時內命名，巔峰上望中等熱帶風暴。

ZCZC 412
WTIO30 FMEE 200631
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 3/1/20152016
1.A TROPICAL DEPRESSION  1
2.A POSITION 2015/11/20 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 10.3 S / 72.8 E
(TEN    DECIMAL THREE   DEGREES SOUTH AND SEVENTY TWO    DECIMAL
EIGHT   DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 16 KT
3.A DVORAK ANALYSIS: 2.5/2.5/S 0.0/12 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:  SE:  SW: 110 NW:
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 500 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2015/11/20 18 UTC: 10.6 S / 72.1 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
24H: 2015/11/21 06 UTC: 11.1 S / 71.8 E, MAX WIND=035 KT, MODERATE
TROPICAL STORM
36H: 2015/11/21 18 UTC: 11.7 S / 71.8 E, MAX WIND=045 KT, MODERATE
TROPICAL STORM
48H: 2015/11/22 06 UTC: 12.3 S / 72.1 E, MAX WIND=040 KT, MODERATE
TROPICAL STORM
60H: 2015/11/22 18 UTC: 13.4 S / 73.0 E, MAX WIND=035 KT, MODERATE
TROPICAL STORM
72H: 2015/11/23 06 UTC: 14.5 S / 74.3 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
2.B LONGER-RANGE OUTLOOK :
96H: 2015/11/24 06 UTC: 17.6 S / 76.8 E, MAX WIND=025 KT, LOW
2.C ADDITIONAL INFORMATION:
FT=2.5- CI=2.5-
DURING THE LAST 6 HOURS, THE SYSTEM DISPLAYS SOME SIGNS OF
ORGANISATION WITH THE EMERGENCE OF A CURVED BAND NEAR THE CENTER,
WHICH SEEMS TO STRENGTHEN SINCE 0300Z. CENTRAL MSLP HAS BEEN
ESTIMATED THANKS TO BUOY NB 1400569 WHICH INDICATED A CORRECTED
PRESSURE OF 1001.6 AT 0400Z. PARTIAL ASCAT SWATH AT 0412Z INDICATES
MAXIMAL WINDS OF 25KT AND LOCALLY 30KT IN THE WESTERN SEMI-CIRCLE.
CONSIDERING THESE ELEMENTS AND THE IMPROVING SYSTEM PATTERN,
INTENSITY HAS BEEN INCREASED TO THE MINIMAL STAGE OF TROPICAL
DEPRESSION.
THE SYSTEM KEEPS ON HEADING WESTSOUTHWESTWARD QUITE QUICKLY ON THE
NORTHERN SIDE OF A WEAK SUBTROPICAL RIDGE. THE LAST TRACK FORECAST
REMAINS CLOSE TO THE PREVIOUS ONE. THE SYSTEM SHOULD START TO SLOW
DOWN. FRIDAY NIGHT, THIS RIDGE IS EXPECTED TO WEAKEN, LEAVING A
SIGNIFICANT WEAKNESS IN THE PRESSURE FIELD TO THE SOUTH OF THE
SYSTEM. AN EQUATORIAL MID LEVEL RIDGE LOCATED TO THE EAST-NORTH-EAST
OF THE SYSTEM SHOULD GRADUALLY STEERED THE SYSTEM SOUTHWARDS AND THEN
SOUTHEASTWARDS FROM SATURDAY AND BEYOND WITH A GRADUAL INCREASE IN
FORWARD MOTION. THE CURRENT FORECAST IS BETWEEN THE AVERAGE OF ALL
THE AVAILABLE GUIDANCE AND THE AVERAGE TRACK OF UK-GFS-EURO OF 12Z.
TODAY, THE ORGANIZATION SHOULD CONTINUE TO IMPROVE. WITH A GOOD UPPER
LEVEL ENVIRONMENT AND HIGH SST, SOME STEADY STRENGTHENING IS LIKELY
LATER TODAY OR TONIGHT. SUNDAY, THE NORTHERLY SHEAR IS FORECAST TO
INCREASE AND THIS SHOULD CALL THE END OF THE FAVORABLE WINDOW FOR
INTENSIFICATION. MOST OF THE GUIDANCE SUGGEST A MODEST TROPICAL
CYCLONE AT ITS BEST ... AND THIS IS REFLECTED IN THE CURRENT
INTENSITY FORECAST.=
NNNN

甜心

:o94s這隻熱低壓的螺旋幅度好有氣勢結構很不錯，它或許將有很大的機率成旋為南印度洋展開今年的風季呢那邊現在已經是夏天嚕。

krichard2011

螺旋性相當漂亮 JTWC 稍早率先升格 TS

Meow

已命名Annabelle。



WTIO30 FMEE 210014

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

0.A WARNING NUMBER: 6/1/20152016
1.A MODERATE TROPICAL STORM  1  (ANNABELLE)

2.A POSITION 2015/11/21 AT 0000 UTC:
WITHIN 20 NM RADIUS OF POINT 10.0 S / 70.9 E
(TEN    DECIMAL ZERO   DEGREES SOUTH AND SEVENTY    DECIMAL NINE
DEGREES EAST)
MOVEMENT :   UNDETERMINED

3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/12 H

4.A CENTRAL PRESSURE: 995 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT
RADIUS OF MAXIMUM WINDS (RMW) :28 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 110 SE: 110 SW: 90 NW: 70
34 KT NE: 40 SE: 40 SW:  NW:



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP

1.B FORECASTS:
12H: 2015/11/21 12 UTC: 10.8 S / 70.4 E, MAX WIND=045 KT, SEVERE
TROPICAL STORM
24H: 2015/11/22 00 UTC: 11.7 S / 70.3 E, MAX WIND=040 KT, MODERATE
TROPICAL STORM
36H: 2015/11/22 12 UTC: 12.9 S / 71.1 E, MAX WIND=035 KT, MODERATE
TROPICAL STORM
48H: 2015/11/23 00 UTC: 14.1 S / 72.3 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
60H: 2015/11/23 12 UTC: 15.4 S / 73.9 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
72H: 2015/11/24 00 UTC: 16.6 S / 74.7 E, MAX WIND=025 KT, REMNANT LOW

2.B LONGER-RANGE OUTLOOK :
96H: 2015/11/25 00 UTC: 18.7 S / 73.3 E, MAX WIND=020 KT, LOW
120H: 2015/11/26 00 UTC: 19.6 S / 71.1 E, MAX WIND=020 KT, LOW

2.C ADDITIONAL INFORMATION:
FT=CI=3.0-

DURING THE LAST 6 HOURS, DEEP CONVECTION HAS DEVELOPED OVER THE
CENTER INTO A IRREGULAR CDO PATTERN, WITH A LARGE BANDE IN THE EAST.

THE CURRENT WESTWARDS TRACK HAS CLEARLY SLOW DOWN DURING THE NEXT
HOURS, ALL AVAILABLE NWP FORECAST TRACK TO BEND SOUTH SOUTHWESTWARDS
THEN SOUTHWESTWARD TOWARDS A WEAKNESS IN THE PRESSURE FIELD TO THE
SOUTH OF THE SYSTEM.
AN EQUATORIAL MID LEVEL RIDGE IS EXPECTED TO BUILD IN THE
EAST-NORTH-EAST OF THE SYSTEM AND SHOULD GRADUALLY STEERED THE SYSTEM
SOUTHWARDS AND THEN SOUTHEASTWARDS FROM SATURDAY AND BEYOND WITH A
GRADUAL INCREASE IN FORWARD MOTION.

ALONG THIS TRACK, ENVIRONMENTAL CONDITIONS REMAIN FAVOURABLE WITH A
GOOD UPPER LEVEL DIVERGENCE, WEAK VERTICAL WINDSHEAR AND TWO OUTFLOW
CHANNELS UNTIL SATURDAY EVENING. THIS WINDOW FOR INTENSIFICATION
SHOULD ALLOW THE SYSTEM TO GRADUALLY STRENGTHEN UP TO THE GREATER
STAGE OF TROPICAL STORM.
BUT ON SUNDAY, NORTHERLY VERTICAL WINDSHEAR SHOULD INCREASE AHEAD A
UPPER LEVEL TROUGH AND THE SYSTEM SHOULD QUICKLY WEAKEN. ON TUESDAY,
THE RESIDUAL LOW SHOULD TRACK EASTWARDS IN THE TRADES FLOW FILLING UP
PROGRESSIVELY.=