![Image](http://www.nrlmry.navy.mil/htdocs_dyn_apache/PUBLIC/tc_pages/thumbs/medium/tc12/SHEM/13S.HILWA/ir/geo/1km/20120220.1900.meteo7.x.ir1km.13SHILWA.35kts-996mb-190S-646E.100pc.jpg)
WTIO30 FMEE 201836
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 17/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/20 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 18.8 S / 64.6 E
(EIGHTEEN DECIMAL EIGHT DEGREES SOUTH AND SIXTY FOUR DECIMAL SIX
DEGREES EAST)
MOVEMENT : WEST 7 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/6 H
4.A CENTRAL PRESSURE: 994 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT
RADIUS OF MAXIMUM WINDS (RMW) :46 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 110 SW: 110 NW: 70
34 KT NE: 50 SE: 70 SW: 70 NW: 50
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/21 06 UTC: 19.4 S / 63.6 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
24H: 2012/02/21 18 UTC: 20.2 S / 62.9 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
36H: 2012/02/22 06 UTC: 21.5 S / 62.4 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
48H: 2012/02/22 18 UTC: 23.4 S / 62.2 E, MAX WIND=030 KT, TROPICAL DEPRESSION
60H: 2012/02/23 06 UTC: 25.5 S / 62.6 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
72H: 2012/02/23 18 UTC: 28.5 S / 63.6 E, MAX WIND=020 KT, LOW
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T=CI=3.0
CONVECTION HAS BUILT OVER THE CENTRE OF THE SYSTEM SINCE 14Z.
HILWA IS LOCATED BELOW THE AXIS OF THE UPPER TROPOSPHERIC RIDGE AND THE
UPPER LEVEL WIND SHEAR IS WEAK (CF. CIMSS ANALYSIS).
LOWER LEVEL ENVIRONMENTAL CONDITIONS ARE MARGINAL : MONSOONFEEDING REMAINS POOR. SST ARE FAVOURABLE NORTH OF 26S.
WITHIN THE NEXT 24 HOURS, SYSTEM IS EXPECTED TO RECURVE SOUTH-WEST AND
THEN SOUTH-SOUTH-WESTWARD UNDER THE STEERING INFLUENCE OF THE MID
TROPOSPHERIC RIDGE IN ITS EAST.
UP TO 24TAU, ENVIRONMENTAL CONDITIONS SHOULD LITTLE CHANGE AND THE
INTENSITY OF THE SYSTEM SHOULD LITTLE CHANGE.
AT 36TAU AND BEYOND, NORTHWESTERLY UPPER LEVEL WIND SHEAR IS EXPECTED
TO INCREASE SHARPLY AND SYSTEM IS FORECAST TO WEAKEN RAPIDLY AND
MERGE WITH A POLAR TROUGH BY 72TAU.