05S.Bohale 短暫升格成為有名字的熱帶低壓

t02436 · 2015-12-12 00:44

MFR00Z命名之後，在06Z立刻降格為熱帶低壓
12Z報預測後期將受風切影響，不再看好重回中度熱帶風暴強度

** WTIO30 FMEE 111232 ***

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

0.A WARNING NUMBER: 11/2/20152016
1.A TROPICAL DEPRESSION 2 (EX-BOHALE)

2.A POSITION 2015/12/11 AT 1200 UTC:
WITHIN 30 NM RADIUS OF POINT 16.9 S / 68.6 E
(SIXTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY EIGHT DECIMAL
SIX DEGREES EAST)
MOVEMENT : SOUTH-WEST 8 KT

3.A DVORAK ANALYSIS: 2.0/2.5/S 0.0/12 H

4.A CENTRAL PRESSURE: 999 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW) :83 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 190 SW: 190 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM

1.B FORECASTS:
12H: 2015/12/12 00 UTC: 18.1 S / 67.6 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
24H: 2015/12/12 12 UTC: 19.4 S / 66.7 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
36H: 2015/12/13 00 UTC: 21.3 S / 65.8 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
48H: 2015/12/13 12 UTC: 23.3 S / 64.6 E, MAX WIND=025 KT,
POST-TROPICAL DEPRESSION
60H: 2015/12/14 00 UTC: 25.0 S / 63.6 E, MAX WIND=025 KT,
POST-TROPICAL DEPRESSION
72H: 2015/12/14 12 UTC: 26.5 S / 63.5 E, MAX WIND=025 KT,
POST-TROPICAL DEPRESSION

2.B LONGER-RANGE OUTLOOK :
96H: 2015/12/15 12 UTC: 28.2 S / 64.5 E, MAX WIND=020 KT, LOW
120H: 2015/12/16 12 UTC: 29.4 S / 67.8 E, MAX WIND=015 KT, REMNANT
LOW

2.C ADDITIONAL INFORMATION:
FT=2.0+ AND CI=2.5-

DURING THE LAST 6 HOURS, DEEP CONVECTION REMAINED CLOSE TO ITS
PREVIOUS LEVEL OF 06Z. MICROWAVE 39GHZ AMSR2 DATA AT 0821Z DO NOT
SHOW A SIGNIFICANT CHANGE IN THE LOW LEVEL PATTERN. VISIBLE IMAGERY
SHOW THAT CONVECTION IS CONFINED TO THE SOUTHERN SEMI-CIRCLE, CLOSE
TO THE LLCC. PRECIPITABLE WATER IMAGERY REVEALS THE ADVECTION OF DRY
AIR BY THE NORTH-WEST TO NORTH SECTORS OF THE CIRCULATION. THE
GENERAL FEELING IS THAT THIS SYSTEM IS ONLY MAKING A LIVING OF SORTS
DESPITE THE WEAKENED VERTICAL WINDSHEAR.

EX-BOHALE IS CURRENTLY TRACKING SOUTHWESTWARD, STEERED BY A MID
LEVELS RIDGE IN THE EAST AND A GEOPOTENTIAL WEAKNESS IN THE SOUTH.
AVAILABLE NWP GUIDANCE STILL OVERESTIMATE THE SYSTEM INTENSITY.THE
ECMWF MODEL REMAINS THE MOST MODERATE IN TERMS OF INTENSITY. THE
CHOSEN SCENARIO IS THUS CLOSE TO THE ECMWF FORECAST, WITH THE
INTENSITY FLUCTUATING AROUND THE CURRENT LEVEL DURING THE NEXT 24
HOURS.

THE SYSTEM IS CURRENTLY AT THE FAR WESTERN SIDE OF THE UPPER LEVEL
RIDGE. FROM SATURDAY, THE NORTHWESTWARD VERTICAL WINDSHEAR AHEAD A
NEW UPPER LEVEL TROUGH SHOULD GRADUALLY STRENGTHEN TO BECOME MODERATE
THEN STRONG THE NEXT FEW DAYS. THUS, THE SYSTEM SHOULD WEAKEN UNDER
THIS UNFAVORABLE UPPER CONSTRAINT AND THE LACK OF OCEANIC CONTENT,
ESPECIALLY SOUTH OF 20S. FROM MONDAY, THE SYSTEM SHOULD CURVE
SOUTHEASTWARD AND FILL UP GRADUALLY.=