SIO: HILWA - Moderate Tropical Storm (13S)

[HURAKAN]

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.

[HURAKAN]

WTIO30 FMEE 210043
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 18/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/21 AT 0000 UTC:
WITHIN 30 NM RADIUS OF POINT 19.2 S / 64.2 E
(NINETEEN DECIMAL TWO DEGREES SOUTH AND SIXTY FOUR DECIMAL TWO
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 6 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/12 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: 70 SW: 110 NW: 70
34 KT NE: 60 SE: 60 SW: 60 NW: 60
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 12 UTC: 19.6 S / 63.1 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
24H: 2012/02/22 00 UTC: 20.8 S / 62.7 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
36H: 2012/02/22 12 UTC: 22.3 S / 62.6 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
48H: 2012/02/23 00 UTC: 24.6 S / 62.7 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
60H: 2012/02/23 12 UTC: 29.5 S / 63.7 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
72H: 2012/02/24 00 UTC: 35.5 S / 64.4 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T=CI=3.0
AN IMPORTANT CDO HAS DEVELOPED ABOVE THE CENTRE OF HILWA SINCE
19/1400Z UNDER THE DIURNAL EFFECT AND THE LOWERING OF THE UPPER LEVEL
CONSTRAINT. LAST IR SATELLITE PICTURES SHOWS THAT THIS CDO IS WEAKENING.HOWEVER RECENT MICRO-WAVE IMAGERY (CF. N19 AT 19/2028Z) SUGGESTS THAT
ORGANIZATION OF THE CONVECTION DIDN'T IMPROVE BELOW THE CDO.
THE LOW LEVEL CENTRE IS DIFFICULT TO LOCATE ACCURATELY.
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 : MONSOON
FEEDING IS POOR. DRY AIR ENCOMPASS THE SYSTEM (CF. ANIMATED MIMIC-TPW OF
CIMSS ). SST ARE FAVOURABLE NORTH OF 26S.
WITHIN THE NEXT 24 HOURS, SYSTEM IS EXPECTED TO RECURVE SOUTHWEST,TRANSITING VERY CLOSE TO RODRIGUES ISLAND, AND THEN SOUTHWARD
BEYOND, UNDER THE STEERING INFLUENCE OF THE MID TROPOSPHERIC RIDGE IN
ITS EAST.
NWP MODELS ARE IN TIGHT AGREEMENT FOR THIS TRACK.
UP TO 24TAU, ENVIRONMENTAL CONDITIONS SHOULD REMAIN NEUTRAL
(FAVOURABLE IN ALTITUDE, BUT MARGINAL IN THE LOWER LEVELS) AND SYSTEM
INTENSITY IS EXPECTED TO REMAIN MORE OR LESS STEADY.
AT 24/36TAU AND BEYOND, NORTHWESTERLY UPPER LEVEL WIND SHEAR IS
EXPECTED TO INCREASE SHARPLY. SYSTEM IS FORECAST TO BEGIN AN
EXTRATROPICAL TRANSITION AT THE END OF THE FORECAST (ON THURSDAY).

[HurricaneBill]

So it finally decided to become a named storm.

[HURAKAN]

WTIO30 FMEE 211245
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 20/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/21 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 19.9 S / 63.9 E
(NINETEEN DECIMAL NINE DEGREES SOUTH AND SIXTY THREE DECIMAL NINE
DEGREES EAST)
MOVEMENT : SOUTH-SOUTH-WEST 5 KT
3.A DVORAK ANALYSIS: 2.5/3.0/W 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) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 150 SW: 90 NW: 60
34 KT NE: 50 SE: 60 SW: 60 NW: 30
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1003 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/22 00 UTC: 21.2 S / 63.2 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
24H: 2012/02/22 12 UTC: 23.0 S / 62.6 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
36H: 2012/02/23 00 UTC: 25.9 S / 62.3 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
48H: 2012/02/23 12 UTC: 30.1 S / 62.7 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
60H: 2012/02/24 00 UTC: 35.1 S / 63.6 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T=2.5 CI=3.0
AFTER A PERIOD OF WEAKENING JUST AFTER 06Z, THUNDERSTORM ACTIVITY HAS
FLARED UP ONCE AGAIN CLOSE TO THE CENTER SINCE 0930Z.
THE SOUTHWARDS TURN SUSPECTED THIS MORNING IS CONFIRMED. THE
WESTWARDS MOTION STOPPED JUST AFTER 00Z. SINCE THAT TIME, HILWA HAS
FOLLOWED A STAIRSTEP TRACK. THE SYSTEM IS ROUNDING THE WESTERN SIDE OFTHE SUBTROPICAL RIDGE AND IS LOCATED AHEAD OF AN UPPER TO MID-LEVEL
TROUGH LOCATED TO ITS SOUTHWEST (WELL DEPICTED ON WV IMAGERY TO THE
SOUTHEAST OF MADAGASCAR). WITHIN THIS PATTERN, HILWA IS EXPECTED TO
TRACK GENERALLY SOUTHSOUTHWESTWARDS AND THEN SOUTHWARDS WITH A
GRADUAL INCREASE IN FORWARD SPEED WITHIN THE NEXT FEW DAYS.
HILWA IS CURRENTLY AT ITS CLOSEST POINT APPROACH OF RODRIGUES TO THE
SOUTHEAST. A DIRECT HIT APPEARS RULED OUT NOW. THE ISLAND IS NOW
LOCATED IN THE NORTHWESTERN QUADRANT WITH VERY FEW THUNDERSTORM
ACTIVITY ACCORDING TO LASTEST MW IMAGERY.
UP TO 24 TAU, ENVIRONMENTAL CONDITIONS STILL REMAIN NEUTRAL OR
SLIGHTLY FAVOURABLE (STRONGER UPPER LEVEL DIVERGENCE SOUTH OF THE
SYSTEM). BEYOND, NORTHWESTERLY UPPER LEVEL WIND SHEAR IS EXPECTED TO
INCREASE SHARPLY. SYSTEM IS FORECAST TO BEGIN AN EXTRATROPICAL
TRANSITION THURSDAY.

[HURAKAN]

latest infrared

[HURAKAN]

WTIO30 FMEE 211803
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 21/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/21 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 20.2 S / 63.7 E
(TWENTY DECIMAL TWO DEGREES SOUTH AND SIXTY THREE DECIMAL SEVEN
DEGREES EAST)
MOVEMENT : SOUTH-WEST 4 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/12 H
4.A CENTRAL PRESSURE: 993 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 150 SW: 90 NW: 60
34 KT NE: 50 SE: 60 SW: 60 NW: 30
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1004 HPA / 800 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2012/02/22 06 UTC: 21.2 S / 63.0 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
24H: 2012/02/22 18 UTC: 23.4 S / 62.6 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
36H: 2012/02/23 06 UTC: 27.2 S / 62.8 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
48H: 2012/02/23 18 UTC: 32.4 S / 63.2 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
60H: 2012/02/24 06 UTC: 37.4 S / 64.8 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
AFTER A PERIOD OF WEAKENING JUST AFTER 06Z, THUNDERSTORM ACTIVITY HAS
FLARED UP ONCE AGAIN CLOSE TO THE CENTRE SINCE 0930Z. ON SATELLITE IR
IMAGERY THE SYSTEM SHOWS A LARGE IRREGULAR CDO PATTERN.
THE SOUTHWARDS TURN SUSPECTED THIS MORNING IS CONFIRMED. THE
WESTWARDS MOTION STOPPED JUST AFTER 00Z. SINCE THAT TIME, HILWA HAS
FOLLOWED A STAIRSTEP TRACK. THE SYSTEM IS ROUNDING THE WESTERN SIDE OF
THE SUBTROPICAL RIDGE AND IS LOCATED AHEAD OF AN UPPER TO MID-LEVEL
TROUGH LOCATED TO ITS SOUTHWEST (WELL DEPICTED ON WV IMAGERY TO THE
SOUTHEAST OF MADAGASCAR). WITHIN THIS PATTERN, HILWA IS EXPECTED TO
TRACK GENERALLY SOUTHSOUTHWESTWARDS AND THEN SOUTHWARDS WITH A
GRADUAL INCREASE IN FORWARD SPEED WITHIN THE NEXT FEW DAYS.
UP TO 24 TAU, ENVIRONMENTAL CONDITIONS STILL REMAIN NEUTRAL OR
SLIGHTLY FAVOURABLE (STRONGER UPPER LEVEL DIVERGENCE SOUTH OF THE
SYSTEM). BEYOND, NORTHWESTERLY UPPER LEVEL WIND SHEAR IS EXPECTED TO
INCREASE SHARPLY. SYSTEM IS FORECAST TO BEGIN AN EXTRATROPICAL
TRANSITION THURSDAY.

[HURAKAN]

Latest track

[HURAKAN]

WTIO30 FMEE 220041
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 22/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/22 AT 0000 UTC:
WITHIN 30 NM RADIUS OF POINT 21.3 S / 63.7 E
(TWENTY ONE DECIMAL THREE DEGREES SOUTH AND SIXTY THREE DECIMAL
SEVEN DEGREES EAST)
MOVEMENT : SOUTH 9 KT
3.A DVORAK ANALYSIS: 3.0/3.0/W 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) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 90 SE: 190 SW: 90 NW: 60
34 KT NE: 40 SE: 40 SW: 40 NW: 30
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/22 12 UTC: 23.2 S / 63.4 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
24H: 2012/02/23 00 UTC: 26.0 S / 63.4 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
36H: 2012/02/23 12 UTC: 31.2 S / 63.7 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
48H: 2012/02/24 00 UTC: 36.7 S / 65.0 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T=3.0- CI=3.0.
THE SYSTEM SEEMS TO BE SHEARED WITH THE CENTRE ON THE NORTWESTERN
EDGE OG CONVECTION ON THE LAST SATELLITE IMAGERY (NOAA18 2231Z).
THE SYSTEM IS LOCATED AHEAD OF AN UPPER TO MID-LEVEL TROUGH LOCATED
TO ITS SOUTHWEST (WELL DEPICTED ON WV IMAGERY TO THE SOUTHEAST OF
MADAGASCAR). WITHIN THIS PATTERN, HILWA IS EXPECTED TO TRACK GENERALLY
SOUTH TO SOUTHSOUTHWESTWARDS AND THEN SOUTHWARDS WITH A GRADUAL
INCREASE IN FORWARD SPEED WITHIN THE NEXT FEW DAYS. THE MODERATE VERTICAL WIND SHEAR MAY NOW LIMITE THE POTENTIAL OF
INTENSIFICATION WITHIN ENVIRONMENTAL CONDITIONS NEUTRAL OR SLIGHTLY
FAVOURABLE (STRONGER UPPER LEVEL DIVERGENCE SOUTH OF THE SYSTEM).
THEN NORTHWESTERLY UPPER LEVEL WIND SHEAR IS EXPECTED TO INCREASE
SHARPLY. SYSTEM IS FORECAST TO BEGIN AN EXTRATROPICAL TRANSITION
THURSDAY.

[HURAKAN]

Latest track

[Crostorm]

ZCZC 958
WTIO30 FMEE 221220
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 24/10/20112012
1.A MODERATE TROPICAL STORM 10 (HILWA)
2.A POSITION 2012/02/22 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 23.5 S / 63.5 E
(TWENTY THREE DECIMAL FIVE DEGREES SOUTH AND SIXTY THREE DECIMAL FIVE DEGREES EAST)
MOVEMENT : SOUTH 12 KT
3.A DVORAK ANALYSIS: 2.5/3.0/W 0.5/12 H
4.A CENTRAL PRESSURE: 995 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT
RADIUS OF MAXIMUM WINDS (RMW) :32 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 90 SE: 190 SW: 90 NW: 60
34 KT NE: 50 SE: 60 SW: 50 NW: 40
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1002 HPA / 400 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/23 00 UTC: 27.6 S / 63.2 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
24H: 2012/02/23 12 UTC: 32.3 S / 62.6 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
36H: 2012/02/24 00 UTC: 36.1 S / 63.5 E, MAX WIND=030 KT, EXTRATROPICAL SYSTEM
48H: 2012/02/24 12 UTC: 42.0 S / 66.4 E, MAX WIND=000 , LOW
2.B LONGER-RANGE OUTLOOK :
2.C ADDITIONAL INFORMATIONS:
T=2.5 CI=3.0-
SYSTEM HAS ACCELERATED SOUTHWARDS AND IN RELATIONSHIP WITH THIS MOTION RESISTS LONGER THAN PREVIOU
SLY EXPECTED UNDER THE NORTHWESTERLY VERTICAL WINDSHEAR CONSTRAINT.
HILWA'S LOW LEVEL CIRCULATION CENTRE REMAINS HOWEVER TOTALLY EXPOSED ON THE NORTHWESTERN EDGE OF T
HE MAIN DEEP CONVECTIVE ACTIVITY.
SUBTROPICAL HIGHS IN ITS SOUTH ARE SHIFTING EASTWARDS AND THE SYSTEM IS EXPECTED TO KEEP ON TRACKI
NG GLOBALLY SOUTHWARDS THEN SOUTH-SOUTHEASTWARDS.
ON THIS TRACK, VERTICAL WINDSHEAR SHOULD KEEP ON STRENGTHENING AND HILWA IS EXPECTED TO RAPIDLY WE
AKEN WITHIN THE NEXT HOURS THEN TO BEGIN EXTRATROPICAL TRANSITION FROM THURSDAY.
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