WTIO30 FMEE 061220



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 13/4/20162017

1.A MODERATE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/06 AT 1200 UTC:

WITHIN 10 NM RADIUS OF POINT 18.1 S / 57.2 E

(EIGHTEEN    DECIMAL ONE   DEGREES SOUTH AND FIFTY SEVEN    DECIMAL

TWO   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-WEST 4 KT



3.A DVORAK ANALYSIS: 2.5/3.0/W 1.0/12 H



4.A CENTRAL PRESSURE: 994 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 45 KT

RADIUS OF MAXIMUM WINDS (RMW) :37 KM



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

28 KT NE: 100 SE: 200 SW: 220 NW: 110

34 KT NE: 60 SE: 120 SW: 120 NW: 80







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM



1.B FORECASTS:

12H: 2017/02/07 00 UTC: 19.1 S / 56.6 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

24H: 2017/02/07 12 UTC: 20.8 S / 55.3 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

36H: 2017/02/08 00 UTC: 21.8 S / 53.8 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

48H: 2017/02/08 12 UTC: 22.7 S / 53.2 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

60H: 2017/02/09 00 UTC: 23.6 S / 53.4 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

72H: 2017/02/09 12 UTC: 24.3 S / 54.4 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/10 12 UTC: 25.8 S / 57.3 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

120H: 2017/02/11 12 UTC: 28.2 S / 60.3 E, MAX WIND=030 KT, TROPICAL

DEPRESSION



2.C ADDITIONAL INFORMATION:

T=2.5 CI=3.0+



THE CENTER IS VISIBLE ON THE NORTHWESTERN EDGE OF THE DEEP CONVECTION

ON CLASSICAL IMAGERY SINCE SEVERAL HOURS, AND VERTICAL WIND SHEAR

INTENSITY HAS INCREASED IN THE LAST HOURS.

THE SYSTEM BEGIN A GENERALLY SOUTHWARDS TRACK, AND IS EXPECTED TO

ACCELERATE PROGRESSIVELY.



WITHIN A QUITE FLAT LOW, THE SYSTEM IS FORECASTED TO CONTINUE SOUTH

SOUTH-WESTWARDS UNTIL WEDNESDAY, PASSING NORTH OF REUNION ISLAND AT

THE END OF THURSDAY.

AFTER PASSING NEAR THE MASCAREIGNES ISLAND, THE SYSTEM SHOULD CURVED

POLEWARDS BETWEEN WEDNESDAY AND TUESDAY, AHEAD OF MID-LATITUDE

TROUGH.



THE DEEP LAYERED UPPER TO MID LEVEL TROUGH, LOCATED JUST TO THE

SOUTH-WEST OF THE MASCAREIGNES ISLANDS, IS CURRENTLY STRETCHING

WITHIN THE TROPICAL DOMAIN TOWARDS THE NORTH-WEST AND THEREFORE

INCREASE THE NORTHERLY CONSTRAINT OVER THE SYSTEM. AS THIS FEATURE

EVOLVES TOWARDS A WEST NORTHWESTWARDS MOVING CUT-OFF, INCREASING

UPPER LEVEL DIVERGENCE MAY START TO EASE THE DETRIMENTAL EFFECT OF

THE SHEAR POTENTIALLY ON TUESDAY.

FROM WEDNESDAY, ENVIRONMENTAL CONDITIONS SHOULD BECOME EVEN MORE

FAVORABLE WITH A DECREASING WINDSHEAR. AN ANOTHER TEMPORARILY

INTENSIFICATION TREND MAY OCCUR BEFORE EXTRATROPICAL TRANSITION.=