WTIO30 FMEE 131237



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 16/5/20142015

1.A INTENSE TROPICAL CYCLONE  5  (BANSI)



2.A POSITION 2015/01/13 AT 1200 UTC:

WITHIN 10 NM RADIUS OF POINT 17.2 S / 57.9 E

(SEVENTEEN    DECIMAL TWO   DEGREES SOUTH AND FIFTY SEVEN    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : EAST 4 KT



3.A DVORAK ANALYSIS: 5.5/6.0/S 0.0/24 H



4.A CENTRAL PRESSURE: 938 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 105 KT

RADIUS OF MAXIMUM WINDS (RMW) :13 KM



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

28 KT NE: 350 SE: 310 SW: 240 NW: 240

34 KT NE: 220 SE: 190 SW: 190 NW: 170

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

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



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

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2015/01/14 00 UTC: 17.3 S / 58.3 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

24H: 2015/01/14 12 UTC: 17.8 S / 59.0 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

36H: 2015/01/15 00 UTC: 18.5 S / 59.9 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

48H: 2015/01/15 12 UTC: 19.5 S / 61.0 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE

60H: 2015/01/16 00 UTC: 21.1 S / 62.6 E, MAX WIND=090 KT, INTENSE

TROPICAL CYCLONE

72H: 2015/01/16 12 UTC: 23.0 S / 63.8 E, MAX WIND=085 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2015/01/17 12 UTC: 26.4 S / 68.2 E, MAX WIND=075 KT,

POST-TROPICAL DEPRESSION

120H: 2015/01/18 12 UTC: 29.1 S / 74.5 E, MAX WIND=065 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATIONS:

T=5.5+ CI=6.0+.



DURING THE PAST 6 HOURS, A WEAKENING TREND OF INTENSITY WAS OBSERVED

PROBABLY OWING TO AN EYEWALL REPLACEMENT CYCLE. IT IS CONFIRMED BY

THE 1114Z SSMI MICRO-WAVE PICTURE.



BANSI TRACKS SLOWLY EASTWARD UNDER THE STEERING INFLUENCE OF

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

BANSI SHOULD KEEP THIS TRACK DURING THE NEXT 24H AT A QUITE SLOW

SPEED  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 KEEP ON TRACKING AND

ACCELERATING SOUTH-EASTWARDS UNTIL SATURDAY.



ON THIS FORECAST TRACK, ENVIRONMENTAL CONDITIONS ARE VERY FAVOURABLE

ON TODAY AND WEDNESDAY UNDER THE UPPER LEVEL RIDGE AXIS AS AT LEAST 2

UPPER LEVEL CHANNELS EQUATOR-WARD AND POLEWARD TAKE PLACE WITHIN THE

PERIOD. BANSI IS EXPECTED TO REMAIN INTENSE WITH SLIGHT FLUCTUANT

INTENSITY.



THURSDAY, BANSI IS LIKELY TO SHIFT SOUTH OF THE UPPER LEVEL RIDGE

AXIS AND KEEPS ONLY ITS POLEWARD OUTFLOW CHANNEL AND AN UPPER LEVEL

TROUGH SHOULD GETTING CLOSER FROM ITS SOUTHWEST. THEREFORE, VERTICAL

WINDSHEAR SHOULD INCREASE FROM THURSDAY EVENING.



ON FRIDAY, BANSI IS LIKELY TO BEGIN TO WEAKEN OWING TO WESTERLY

VERTICAL WINDSHEAR AND THE LOWERING OCEANIC HEAT CONTENT.



THE INHABITANTS OF MAURITIUS AND RODRIQUES ISLANDS SHOULD CLOSELY

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