WTIO30 FMEE 160621



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 7/5/20152016

1.A SEVERE TROPICAL STORM  5  (URIAH)



2.A POSITION 2016/02/16 AT 0600 UTC:

WITHIN 20 NM RADIUS OF POINT 17.9 S / 85.5 E

(SEVENTEEN    DECIMAL NINE   DEGREES SOUTH AND EIGHTY FIVE    DECIMAL

FIVE   DEGREES EAST)

MOVEMENT : WEST-SOUTH-WEST 10 KT



3.A DVORAK ANALYSIS: 3.5/3.5/D 0.5/24 H



4.A CENTRAL PRESSURE: 988 HPA

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

RADIUS OF MAXIMUM WINDS (RMW) :74 KM



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

28 KT NE: 220 SE: 410 SW: 440 NW: 240

34 KT NE: 110 SE: 200 SW: 280 NW: 150

48 KT NE: 0 SE: 120 SW: 110 NW: 90





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

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2016/02/16 18 UTC: 17.9 S / 83.4 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

24H: 2016/02/17 06 UTC: 18.0 S / 81.3 E, MAX WIND=070 KT, TROPICAL

CYCLONE

36H: 2016/02/17 18 UTC: 19.1 S / 79.8 E, MAX WIND=080 KT, TROPICAL

CYCLONE

48H: 2016/02/18 06 UTC: 20.7 S / 78.5 E, MAX WIND=075 KT, TROPICAL

CYCLONE

60H: 2016/02/18 18 UTC: 21.9 S / 78.2 E, MAX WIND=070 KT, TROPICAL

CYCLONE

72H: 2016/02/19 06 UTC: 22.7 S / 77.9 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2016/02/20 06 UTC: 23.1 S / 77.1 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

120H: 2016/02/21 06 UTC: 23.6 S / 77.4 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=3.5 CI=3.5



SINCE SUNRISE, DEEP CONVECTION HAS ONCE AGAIN REACHED THE NORTHERN

SEMI-CIRCLE AND SEEMS TO MANAGE TO REMAIN IN THIS AREA. SSMIS 0112Z

MICROWAVE IMAGES CONFIRM THIS ANALYSIS WITH A CONVECTION RING AROUND

THE LLCC, ALTHOUGH IT IS STILL DISCONTINUOUS FOR NOW. WE ALSO

HIGHLIGHT THAT THE MAX WINDS RADIUS HAS BEEN SHRINKING OVER THE LAST

ANALYSIS. UPPER LEVEL CONDITIONS REMAIN CONDUCIVE WITH STILL AN

OUTFLOW CHANNEL IN THE SOUTH. 0306Z ASCAT SWATH CONFIRM THAT THIS

IMPROVED CLOUD PATTERN IS ACCOMPANIED BY A WINDS STRENGTHENING, WITH

STORM FORCE WINDS IN THE SOUTHERN SEMI-CIRCLE AND THE NORTH-WESTERN

QUADRANT. THUS, THESE OBSERVATIONS INDICATE THAT URIAH HAS BEGUN A

NEW INTENSIFICATION PHASE.



URIAH'S TRACK HAS SIGNIFICANTLY BEND WESTWARD SINCE 00Z.THIS EXPECTED

TREND IS DUE TO A BULDING LOW TO MID-LEVELS SUBTROPICAL RIDGE LOCATED

ON ITS SOUTH IN THE WAKE OF A TROUGH THAT HAS BYPASSED THE SYSTEM

YESTERDAY. 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 SLOW DOWN BECAUSE

OF THE BUILDING OF A SECOND RIDGE IN THE SOUTH. FROM FRIDAY NIGHT,

THE EURO ENSEMBLE FORECAST SHOW LARGE SPREAD SUGGESTING INCREASING

UNCERTAINTY. HOWEVER, THE MAJORITY OF THE ENSEMBLE MEMBERS AND THE

OTHER NWP MODELS FORECAST A SOUTHWARD TO SOUTHWESTWARD TRACK STEERED

BY A BAROCLINIC LOW MOVING TOWARDS THE MID-LATITUDES AND CAUSING A

WEAKNESS IN THE SUBTROPICAL RIDGE.



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

THURSDAY WITH A WEAK VERTICAL WINDSHEAR. 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. MOREOVER, THE SLOW

MOTION FORECAST FROM FRIDAY IS EXPECTED TO SIGNIFICANTLY COOL THE SST

AND INCREASE THE WEAKENING TREND.=