15UTC: TC HALEH(17S) undergoing slow extratropical transition


Warning 26/JTWC


1204UTC
1204UTC
TC HALEH 17S
https://www.facebook.com/groups/1817419381676514/
As of 12:00 UTC Mar 08, 2019:
Location: 32.2°S 65.6°E
Maximum Winds: 40 kt (75km/h)
Gusts: 50 kt (95km/h)
Minimum Central Pressure: 988 mb
REMARKS:
081500Z POSITION NEAR 32.9S 65.5E.
TROPICAL CYCLONE (TC) 17S (HALEH), LOCATED APPROXIMATELY 852 NM
SOUTH-SOUTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED SOUTH-
SOUTHWESTWARD AT 12 KNOTS (KTS) OVER THE PAST SIX HOURS. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A FULLY EXPOSED LOW
LEVEL CIRCULATION CENTER WITH ISOLATED DEEP CONVECTION DISPLACED TO
THE SOUTH IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY. THERE IS FAIR
CONFIDENCE IN THE INITIAL INTENSITY OF 40 KTS, WHICH CONTINUES TO BE
HEDGED ABOVE PGTW/KNES DVORAK INTENSITY ESTIMATES OF T2.0-T2.5 (30-
35 KTS) BASED ON EARLIER COMPARISON BETWEEN DVORAK INTENSITIES AND
ASCAT DATA. THE ENVIRONMENT IS UNFAVORABLE OVERALL WITH COOL (25-26
CELSIUS) SEA SURFACE TEMPERATURE AND HIGH (30-35 KT) VERTICAL WIND
SHEAR (VWS) OVERCOMING A STRONG POLEWARD OUTFLOW CHANNEL TO WEAKEN
THE INTENSITY BELOW WARNING THRESHOLD BY TAU 24. INTENSITY GUIDANCE
SUGGESTS THE CYCLONE WILL LINGER AT, OR JUST BELOW, THE WARNING
THRESHOLD OF 35 KTS AS TC 17S UNDERGOES EXTRATROPICAL TRANSITION
(ETT) AND THE WARNING DURATION MAY NEED TO BE EXTENDED UNTIL TAU 48-
72 WHEN ETT SHOULD BE COMPLETED. TC 17S IS TRACKING ALONG THE
PERIPHERY OF A NORTH-SOUTH ORIENTED SUBTROPICAL RIDGE (STR) TO THE
EAST. AROUND TAU 12, THE SYSTEM WILL TURN SOUTHEASTWARD AS IT ROUNDS
THE STR AXIS AND BEGINS TO RECURVE. NUMERICAL MODEL GUIDANCE IS IN
EXCELLENT AGREEMENT, LENDING TO HIGH CONFIDENCE IN THE JTWC TRACK
FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 081200Z IS 33 FEET.
NEXT WARNINGS AT 082100Z, 090300Z AND 090900Z.//
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1413UTC

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1038UTC



Rédigé par PATRICK HOAREAU le Vendredi 8 Mars 2019 à 21:00