WTIO30 FMEE 041839



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 6/4/20162017

1.A SEVERE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/04 AT 1800 UTC:

WITHIN 20 NM RADIUS OF POINT 16.8 S / 56.5 E

(SIXTEEN    DECIMAL EIGHT   DEGREES SOUTH AND FIFTY SIX    DECIMAL

FIVE   DEGREES EAST)

MOVEMENT :   QUASI-STATIONARY



3.A DVORAK ANALYSIS: 3.0/3.0/D 1.5/24 H



4.A CENTRAL PRESSURE: 992 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT

RADIUS OF MAXIMUM WINDS (RMW) :15 KM



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

28 KT NE: 60 SE: 70 SW: 60 NW: 50

34 KT NE: 50 SE: 60 SW: 50 NW: 40

48 KT NE: 20 SE: 20 SW: 20 NW: 20





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 300 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/05 06 UTC: 17.0 S / 56.7 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

24H: 2017/02/05 18 UTC: 17.4 S / 57.0 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

36H: 2017/02/06 06 UTC: 18.2 S / 57.2 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

48H: 2017/02/06 18 UTC: 19.4 S / 56.8 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

60H: 2017/02/07 06 UTC: 20.6 S / 55.3 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

72H: 2017/02/07 18 UTC: 21.6 S / 53.7 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/08 18 UTC: 22.8 S / 50.6 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

120H: 2017/02/09 18 UTC: 25.4 S / 51.2 E, MAX WIND=065 KT, TROPICAL

CYCLONE



2.C ADDITIONAL INFORMATION:

T=CI=3.0+



OVER THE PAST SIX HOURS, CLOUD PATTERN IMPROVED, WITH THE BUILDING OF

A WELL DEFINED CURVED BAND, WRAPPING AROUND A WARM SPOT. LAST

MICROWAVE DATA (SSMIS F18 AND F17 AT 1518Z AND 1438Z, CONFIRM THIS

FEELING, SHOWING AN INCREASE OF THE CURVATURE. HOWEVER DEEP

CONVECTION REMAINS SPARSE IN THE EASTERN PART OF CARLOS. THIS IS

LIKELY DUE TO DRY AIR MASS IN MID TROPOSPHERE, BROUGHT BY THE FLOW.

THEREFORE, IT IS ASSUMED THAT CARLOS IS A STRONG TROPICAL STORM.



AFTER A SOUTH-WESTWARD MOVEMENT TODAY, THE SYSTEM SLOWED DOWN, WITH

THE LACK OF A DEFINED STEERING FLOW. THUS CARLOS TRACK FOR THE NEXT

HOURS REMAINS UNCERTAIN. FROM MONDAY, THE SYSTEM SHOULD GRADUALLY

ACCELERATE TOWARDS THE SOUTH-WEST. THE AVAILABLE GUIDANCE IS IN

RATHER GOOD AGREEMENT ON THIS TRACK FORECAST. NWP GUIDANCE IS

GLOBALLY IN AGREEMENT WITH THIS SCENARIO. THE FORECAST TRACK IS A

CONSENSUS OF LAST AVAILABLE NUMERICAL MODELS.



THE INTENSITY FORECAST FOR THE FOLLOWING 24 HOURS IS ALSO UNCERTAIN

DUE THE SMALL SIZE OF THE SYSTEM. DESPITE, THE SYNOPTIC IMPROVEMENT,

THE EXISTENCE OF DRY AIR CLOSE TO THE INNER CORE MAY HINDER THE

DEEPENING. SO THE PRESENT FORECAST HAS BEEN NUDGED DOWNWARD.FROM

MONDAY, A WEAKENING TREND WITHIN A MARGINAL UPPER LEVEL ENVIRONMENTAL

CONDITIONS, IS EXPECTED AS THE SYSTEM WILL MOVE CLOSE OR OVER THE

MASCAREGNES ISLANDS, INDUCING HIGH UNCERTAINTY ABOUT THE FINAL IMPACT

OVER THOSE SMALL ISLANDS.

INTENSIFICATION IS LIKELY NEAR THE END OF THE FORECAST PERIOD WITHIN

AN IMPROVING UPPER ENVIRONMENT.=