WTIO30 FMEE 151908



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 5/5/20152016

1.A MODERATE TROPICAL STORM  5  (URIAH)



2.A POSITION 2016/02/15 AT 1800 UTC:

WITHIN 20 NM RADIUS OF POINT 17.0 S / 87.3 E

(SEVENTEEN    DECIMAL ZERO   DEGREES SOUTH AND EIGHTY SEVEN

DECIMAL THREE   DEGREES EAST)

MOVEMENT : SOUTH-WEST 6 KT



3.A DVORAK ANALYSIS: 2.5/3.0/W 1.0/24 H



4.A CENTRAL PRESSURE: 991 HPA

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

RADIUS OF MAXIMUM WINDS (RMW) :93 KM



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

28 KT NE: 330 SE: 530 SW: 500 NW: 220

34 KT NE: 190 SE: 410 SW: 300 NW: 170







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1200 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM



1.B FORECASTS:

12H: 2016/02/16 06 UTC: 17.4 S / 85.7 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

24H: 2016/02/16 18 UTC: 17.6 S / 83.7 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

36H: 2016/02/17 06 UTC: 18.1 S / 81.7 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

48H: 2016/02/17 18 UTC: 19.1 S / 80.2 E, MAX WIND=075 KT, TROPICAL

CYCLONE

60H: 2016/02/18 06 UTC: 20.6 S / 79.1 E, MAX WIND=070 KT, TROPICAL

CYCLONE

72H: 2016/02/18 18 UTC: 21.9 S / 78.9 E, MAX WIND=065 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2016/02/19 18 UTC: 23.1 S / 77.9 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

120H: 2016/02/20 18 UTC: 22.9 S / 77.3 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=2.5 CI=3.0



URIAH IS STRUGGLING TO INTENSIFY PROBABLY DUE TO MID-LEVEL DRY AIR

INTRUSION. ECMWF HUMIDITY ANALYSIS AT 12Z REVEAL EXTREMELY MID-LEVELS

(500 HPA) DRY AIR SURROUNDING URIAH WITH HUMIDITY AS LOW AS 5 TO 10%

WITHIN THE NORTHERN SEMI-CIRCLE. SPORADIC BURST OF CONVECTION IS

OCCURRING ALONG THE RMW CURRENTLY. THE LATEST ONE (CF GPM AT 1706Z)

HAS BEEN WITHIN THE WESTERN SEMI-CIRCLE SINCE 15Z. AS THE SAT

PRESENTATION IS STILL GENERALLY SLOWLY DECLINE, THE MAX WINDS IS

REDUCED TO 40 KT (NO ASCAT OVERPASS TO HELP PRECISE THE INTENSITY).





TOMORROW, URIAH IS EXPECTED TO BEND WEST-SOUTH-WESTWARDS, STEERED BY

A LOW TO MID-LEVELS SUBTROPICAL RIDGE LOCATED ON ITS SOUTH. FROM

WEDNESDAY, THE SYSTEM WILL PROGRESSIVELY MOVE TOWARDS THE

SOUTH-SOUTH-WEST, WITH THE REBUILDING OF A MID-LEVEL RIDGE IN THE

EAST. FOR THE END OF THE WEEK, URIAH IS LIKELY TO SLOWDOWN BECAUSE OF

THE BUILDING OF ANOTHER RIDGE IN THE SOUTH. HOWEVER THE SPREAD IN THE

NUMERICAL GUIDANCE INCREASES SIGNIFICANTLY. A LOW LEVEL TROUGH MAY

STEER URIAH SOUTH-EASTWARDS TOWARDS THE MID-LATITUDES.





ON THIS TRACK, UPPER LEVELS CONDITIONS SHOULD REMAIN CONDUCIVE UP TO

THURSDAY WITH A WEAK VERTICAL WINDSHEAR. CURRENT BURST OF CONVECTION

NEAR THE "INNER-CORE" OF URIAH SHOULD ALLOW A RESUME OF A GRADUAL

INTENSIFICATION . ON WEDNESDAY, THE BUILDING OF AN OUTFLOW CHANNEL ON

THE POLAR SIDE ALONG WITH GOOD OCEANIC HEAT CONTAIN NEAR 80E, ARE

LIKELY TO HELP THE SYSTEM INTENSIFYING MORE RAPIDLY. AFTER THURSDAY,

THE ARRIVAL OF AN UPPER TROUGH WILL INCREASE THE NORTH-WESTERLY VWS,

AND START THE WEAKENING, ACCENTUATED BY THE MARGINAL OCEAN HEAT

CONTENT SOUTH OF 23-24S.=