WTIO30 FMEE 120045



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 11/4/20152016

1.A MODERATE TROPICAL STORM  4  (DAYA)



2.A POSITION 2016/02/12 AT 0000 UTC:

WITHIN 30 NM RADIUS OF POINT 29.3 S / 56.3 E

(TWENTY NINE    DECIMAL THREE   DEGREES SOUTH AND FIFTY SIX

DECIMAL THREE   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-EAST 17 KT



3.A DVORAK ANALYSIS: 2.0/2.5/W 0.5/24 H



4.A CENTRAL PRESSURE: 993 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT

RADIUS OF MAXIMUM WINDS (RMW) :NIL



6.A EXTENSION OF WIND BY QUADRANTS (KM):

28 KT NE: 430 SE: 480 SW: 0 NW: 110

34 KT NE: 110 SE: 220 SW: 0 NW: 0







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1000 HPA / 400 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM



1.B FORECASTS:

12H: 2016/02/12 12 UTC: 33.1 S / 57.7 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

24H: 2016/02/13 00 UTC: 37.5 S / 60.3 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

36H: 2016/02/13 12 UTC: 41.4 S / 65.7 E, MAX WIND=040 KT,

EXTRATROPICAL SYSTEM









2.B LONGER-RANGE OUTLOOK :







2.C ADDITIONAL INFORMATION:

T=2.0+ CI=2.5+



THE CLOUD PATTERN IS A SHEAR PATTERN WITH THE CENTER LOCATED ON THE

WESTERN EDGE OF THE DEEP CONVECTION ON IR IMAGERY. MW (AMSU-B OF

1805Z, 2220Z AND SSMI AT 2208Z) REVEAL AN EXPOSED CENTER. PREVIOUS

VERY PARTIAL ASCAT DATA SUGGEST THAT SOME MINIMAL GALE FORCE WINDS IS

STILL EXISTING WITHIN THE EASTERN SEMI-CIRCLE.



THE ENVIRONMENTAL CONDITIONS BECOME REALLY UNFAVOURABLE WITH COOL SST

AND STRONG VWS ASSOCIATED WITH INCREASING WESTERLIES. THE

POST-TROPICAL STATUS IS EXPECTED LATER TODAY AND LIKELY WITHIN THE

NEXT 6 HOURS.



THE EVACUATION OF THE SYSTEM TOWARDS THE MID-LATITUDE IS STEERED BY

BOTH A CUT-OFF LOW IN THE SOUTH-WEST AND A HIGH GEOPOTENTIAL AREA IN

THE EAST. UNDER THE JOINED INFLUENCE OF THESE TWO SYNOPTIC

STRUCTURES, THE AVAILABLE NWP MODELS STILL FORECAST SIMILAR

SOUTH-EAST TRACKS WITH MORE SPREAD THIS WEEK-END DUE TO DIFFERENT

FOREWARD MOTION .



LAST WARNING ON THIS SYSTEM. PLEASE REFER TO FQIO20 BULLETIN ISSUED

TWICE DAILY (06 UTC AND 18 UTC) FOR FURTHER INFORMATION.=