15UTC: Cyclone HALEH(17S) weakening and forecast to be a cold-core mid latitude low in 48hours


Warning 22/JTWC


1445UTC
1445UTC
TC HALEH 17S
https://www.facebook.com/groups/1817419381676514/
As of 12:00 UTC Mar 07, 2019:
Location: 27.1°S 67.3°E
Maximum Winds: 60 kt (110km/h)
Gusts: 75 kt (140km/h)
Minimum Central Pressure: 975 mb
REMARKS:
071500Z POSITION NEAR 27.7S 67.0E.
TROPICAL CYCLONE (TC) 17S (HALEH), LOCATED APPROXIMATELY 691 NM
SOUTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED SOUTH-SOUTHWESTWARD
AT 09 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS AN 130 NM CIRRUS SHIELD WITH ISOLATED DEEP
CONVECTION THAT IS OBSCURING THE LOW LEVEL CIRCULATION CENTER
(LLCC). LOW LEVEL RAIN BANDS ARE VISIBLE BEYOND THE CIRRUS SHIELD IN
ALL QUADRANTS. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE
BY EXTRAPOLATING FROM A FAIRLY WELL-DEFINED LLCC IN A 071106Z SSMI
85 GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 60 KTS IS AVERAGED
BETWEEN PGTW AND KNES DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55
KTS) AND T4.0 (65 KTS), RESPECTIVELY. THE ENVIRONMENT IS UNFAVORABLE
FOR INTENSIFICATION WITH MARGINAL (26-27 CELSIUS) SEA SURFACE
TEMPERATURE (SST) AND HIGH (25-30 KT) VERTICAL WIND SHEAR (VWS)
OFFSETTING A STRONG POLEWARD OUTFLOW CHANNEL. TC 17S IS TRACKING
ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR). BY TAU 36,
TC 17S WILL ROUND THE STR AXIS AND BEGIN RECURVING SOUTHEASTWARD.
THE INCREASINGLY UNFAVORABLE ENVIRONMENT WILL CAUSE STEADY WEAKENING
AND THE INTENSITY IS EXPECTED TO FALL TO 40 KTS BY TAU 48.
EXTRATROPICAL TRANSITION (ETT) WILL BEGIN AROUND TAU 24 AS
TEMPERATURE ADVECTION BECOMES MORE SIGNIFICANT AND THE CYCLONE
BEGINS TO INTERACT WITH THE MID-LATITUDE WESTERLIES. BY TAU 48, ETT
IS EXPECTED TO BE COMPLETED AND TC 17S WILL BECOME A COLD-CORE, MID-
LATITUDE CYCLONE. NUMERICAL MODEL GUIDANCE IS IN STRONG AGREEMENT,
LENDING TO HIGH CONFIDENCE IN THE JTWC TRACK FORECAST, WHICH IS
PLACED CLOSE TO THE MULTI-MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 071200Z IS 25 FEET. NEXT WARNINGS AT 072100Z, 080300Z,
080900Z AND 081500Z.//
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1217UTC
1217UTC

 

1054UTC
1054UTC

0945UTC
0945UTC



Rédigé par PATRICK HOAREAU le Jeudi 7 Mars 2019 à 19:25