WTIO30 FMEE 121811



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 13/5/20142015

1.A INTENSE TROPICAL CYCLONE  5  (BANSI)



2.A POSITION 2015/01/12 AT 1800 UTC:

WITHIN 15 NM RADIUS OF POINT 17.7 S / 56.9 E

(SEVENTEEN    DECIMAL SEVEN   DEGREES SOUTH AND FIFTY SIX    DECIMAL

NINE   DEGREES EAST)

MOVEMENT :   QUASI-STATIONARY



3.A DVORAK ANALYSIS: 6.5/6.5/D 1.0/12 H



4.A CENTRAL PRESSURE: 932 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 110 KT

RADIUS OF MAXIMUM WINDS (RMW) :17 KM



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

28 KT NE: 310 SE: 360 SW: 280 NW: 310

34 KT NE: 190 SE: 150 SW: 90 NW: 130

48 KT NE: 110 SE: 90 SW: 70 NW: 90

64 KT NE: 60 SE: 60 SW: 60 NW: 60



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 1000 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2015/01/13 06 UTC: 17.8 S / 57.3 E, MAX WIND=115 KT, INTENSE

TROPICAL CYCLONE

24H: 2015/01/13 18 UTC: 17.8 S / 57.7 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

36H: 2015/01/14 06 UTC: 17.9 S / 58.2 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

48H: 2015/01/14 18 UTC: 18.5 S / 59.0 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

60H: 2015/01/15 06 UTC: 19.5 S / 60.1 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE

72H: 2015/01/15 18 UTC: 20.8 S / 61.6 E, MAX WIND=095 KT, INTENSE

TROPICAL CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2015/01/16 18 UTC: 23.9 S / 64.7 E, MAX WIND=080 KT, TROPICAL

CYCLONE

120H: 2015/01/17 18 UTC: 28.6 S / 70.2 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM



2.C ADDITIONAL INFORMATIONS:

SATELLITE FEATURES HAS IMPROVED DURING THE LAST HOURS, WITH A WARMER

EYE, AND A CDO MORE SYMETRIC AND COLDER, EVIDENCE OF THE

INTENSIFICATION. THE SYSTEM SEEMS TO BE QUITE STATIONARY SINCE DE

LAST THREE HOURS ACCORDING TO RADAR DATA OF REUNION ISLAND

(COLORADO).



BANSI SHOULD BEGIN A SLOW TRACK GENERALLY EASTWARD UNDER THE STEERING

INFLUENCE OF MID-LEVEL RIDGE WHICH IS BUILDING NORTH OF THE SYSTEM.

BANSI SHOULD KEEP THIS TRACK DURING THE NEXT 36H AT A QUITE SLOW

SPEED TOMORROW WITHIN A WEAK STEERING ENVIRONMENT.



ON WEDNESDAY, THE MID-LEVEL RIDGE SHIFTS BACK IN THE EAST OF THE

SYSTEM AND A COL BUILDS IN ITS SOUTH, A SOUTH-EASTWARDS MOTION IS

THEN EXPECTED.

BANSI IS THEN EXPECTED TO KEEPS ON TRACKING AND ACCELERATING

SOUTH-EASTWARDS UNTIL SATURDAY.



ON THIS FORECAST TRACK, ENVIRONMENTAL CONDITIONS ARE VERY FAVOURABLE

ON MONDAY, TUESDAY AND WEDNESDAY UNDER THE UPPER LEVEL RIDGE AXIS AS

AT LEAST 2 UPPER LEVEL CHANNELS EQUATOR-WARD AND POLEWARD TAKE PLACE

WITHIN THE PERIOD. A THIRD ONE TOWARDS THE EAST IS EXPECTED TO

TEMPORARILY EXIST ON TUESDAY.

ON AND AFTER THURSDAY, BANSI SHIFTS SOUTH OF THE UPPER LEVEL RIDGE

AXIS AND KEEPS ONLY ITS POLEWARD OUTFLOW CHANNEL.

A WESTERLY VERTICAL WINDSHEAR STRENGTHENS ON FRIDAY OVER LIMITED HEAT

OCEANIC CONTENTS.



THERE IS AN IMPORTANT LIKELIHOOD THAT A VERY DANGEROUS INTENSE

TROPICAL CYCLONE REPRESENTS A POTENTIAL THREAT FOR THE MASCAREIGNES

WITHIN SEVERAL DAYS (FROM MONDAY TO THURSDAY).



THE INHABITANTS OF THE MASCAREIGNES ISLANDS SHOULD THEREFORE CLOSELY

MONITOR THE PROGRESS OF THIS DANGEROUS SYSTEM WITHIN THE NEXT DAYS.=