WTIO30 FMEE 070651



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 16/4/20162017

1.A MODERATE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/07 AT 0600 UTC:

WITHIN 10 NM RADIUS OF POINT 19.3 S / 55.3 E

(NINETEEN    DECIMAL THREE   DEGREES SOUTH AND FIFTY FIVE    DECIMAL

THREE   DEGREES EAST)

MOVEMENT : WEST 8 KT



3.A DVORAK ANALYSIS: 2.5/3.0/S 0.0/6 H



4.A CENTRAL PRESSURE: 995 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT

RADIUS OF MAXIMUM WINDS (RMW) :37 KM



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

28 KT NE: 110 SE: 370 SW: 370 NW: 110

34 KT NE: 70 SE: 90 SW: 90 NW: 70







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 800 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/07 18 UTC: 20.7 S / 54.1 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

24H: 2017/02/08 06 UTC: 22.0 S / 53.3 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

36H: 2017/02/08 18 UTC: 22.9 S / 53.0 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

48H: 2017/02/09 06 UTC: 23.9 S / 53.3 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

60H: 2017/02/09 18 UTC: 24.6 S / 54.4 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

72H: 2017/02/10 06 UTC: 25.2 S / 55.7 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/11 06 UTC: 26.3 S / 58.7 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

120H: 2017/02/12 06 UTC: 27.2 S / 59.2 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=2.5 CI=3.0-



AFTER BEING TOTALLY EXPOSED AT SUNRISE, THE LOW LEVEL CENTER WAS

LOCATED AT 06Z UNDER AN OTHER CONVECTIVE BURST. DESPITE THE

NORTH-WESTERLY UPPER CONSTRAINT, SUCCESSIVE CONVECTIVE BURSTS REMAIN

RATHER CLOSE TO THE LLCC. 0549Z ASCAT SWATH COVERS THE EASTERN HALF

OF THE CIRCULATION AND REVEALS MAX WINDS OF 35/40KT, IN AGREEMENT

WITH DVORAK ESTIMATES.



WITHIN THE NEXT HOURS, CARLOS IS FORECAST TO HEAD SOUTH-WESTWARD

AGAIN UNTIL WEDNESDAY MORNING, TRACKING JUST NORTH OF REUNION ISLAND

THIS AFTERNOON. WEDNESDAY, UNDER THE GROWING INFLUENCE OF A

MID-TROPOSPHERIC RIDGE IN THE NORTH-EAST AND A SURFACE TROUGH IN THE

SOUTH COMING FROM THE MID-LATITUDES, CARLOS' TRACK SHOULD BEND

SOUTHWARD THEN SOUTH-EASTWARD.



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

SOUTH-WEST OF THE MASCARENES ISLANDS, STILL PRODUCES A NORTHERN TO

NORTHWESTERN VERTICAL WINDSHEAR BUT THIS CONSTRAINT HAS BEEN

WEAKENING OVER THE PAST HOURS ACCORDING TO LAST CIMSS DATA. THIS

TROUGH SHOULD GRADUALLY SPLIT UP WITH A CUT-OFF LOW ISOLATING ITSELF

OVER MADAGASCAR AND THE SOUTHERN HALF SHIFTING EASTWARDS. THUS, THE

VERTICAL WINDSHEAR SHOULD SIGNIFICANTLY WEAKEN FROM TUESDAY EVENING

WHILE THE UPPER LEVEL DIVERGENCE REMAINS STRONG IN THE SOUTHEASTERN

QUADRANT. THIS UPPER LEVEL CONTEXT SHOULD ALLOW CARLOS TO BEGIN A

SECOND PHASE OF INTENSIFICATION. BUT FROM THURSDAY, THE SYSTEM WILL

TRACK AHEAD OF A NEW MID-LATITUDE UPPER LEVEL TROUGH. AT THE FIRST,

CARLOS' SOUTHEASTWARD TRACK SHOULD MITIGATE THE NORTHWESTWARD

VERTICAL WINDSHEAR INFLUENCE. HOWEVER FROM SATURDAY, WINDSHEAR SHOULD

BECOME TOO STRONG AND CARLOS SHOULD BEGIN TO WEAKEN.=