#150 Postby HURAKAN » Sat Feb 18, 2012 8:32 am
WTIO30 FMEE 180716 CCA
***************CORRECTIVE**************
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 38/9/20112012
1.A TROPICAL CYCLONE 9 (GIOVANNA)
2.A POSITION 2012/02/18 AT 0600 UTC:
WITHIN 10 NM RADIUS OF POINT 26.3 S / 43.6 E
(TWENTY SIX DECIMAL THREE DEGREES SOUTH AND FORTY THREE DECIMAL SIX
DEGREES EAST)
MOVEMENT : EAST 3 KT
3.A DVORAK ANALYSIS: 4.0/4.5/D 0.5/6 H
4.A CENTRAL PRESSURE: 972 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 65 KT
RADIUS OF MAXIMUM WINDS (RMW) :52 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 190 SE: 220 SW: 190 NW: 170
34 KT NE: 150 SE: 160 SW: 150 NW: 140
48 KT NE: 90 SE: 90 SW: 80 NW: 80
64 KT NE: 50 SE: 50 SW: 50 NW: 50
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 500 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2012/02/18 18 UTC: 26.4 S / 45.5 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
24H: 2012/02/19 06 UTC: 26.0 S / 47.8 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
36H: 2012/02/19 18 UTC: 25.6 S / 49.7 E, MAX WIND=055 KT, SEVERE TROPICAL STORM
48H: 2012/02/20 06 UTC: 25.3 S / 51.2 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
60H: 2012/02/20 18 UTC: 25.1 S / 52.2 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
72H: 2012/02/21 06 UTC: 25.0 S / 52.9 E, MAX WIND=030 KT, TROPICAL DEPRESSION
2.B LONGER-RANGE OUTLOOK :
96H: 2012/02/22 06 UTC: 25.1 S / 55.1 E, MAX WIND=020 KT, LOW
2.C ADDITIONAL INFORMATIONS:
T=4.0+- CI=4.5-
DT 6 HOURS AVERAGE HAS REACHED 4.5- AT 0300Z. AFTER THIS MAXIMUM, PATTERN
IS CLEARLY DETERIORATING. 0209Z TRMM AND 0428Z F18 SHOW THIS RECENT
DETERIORATION. SYSTEM IS CLASSIFIED TROPICAL CYCLONE DUE TO 0300Z
INTENSITY PEAK. GIOVANNA SEEMS UNDERGO THE INFLUENCE OF THE COAST OFSOUTH MADAGASCAR.
GIOVANNA IS STILL LOCATED BETWEEN TWO MID LEVEL HIGHS GENERATING
CONTRADICTORY STEERING FLOWS OVER THE SYSTEM. WITHIN THE NEXT HOURS,
THE EASTERN RIDGE MIGHT SHIFT GRADUALLY EASTWARD AND GIOVANNA
SHOULD BE STEERED BY A WESTERLY TO WEST-NORTHWESTERLY FLOW ON THE
SOUTH-EASTERN BORDER OF THE MID LEVEL HIGHS LOCATED OVER SOUTH
AFRICA AND ON THE NORTHERN EDGE OF THE MID-LATITUDES WESTERLIES. SO,
SYSTEM SHOULD GRADUALLY ACCELERATE ON AN EASTWARDS TO EASTNORTHEASTWARDS TRACK. BEYOND SUNDAY EVENING, NWP MODELS ARE STILL IN
POOR AGREEMENT WITH TWO POSSIBILITIES: A CONTINUING EASTWARDS TRACK
OR A RATHER SHARP NORTHWARDS TURN ALONG THE SOUTHEASTERN COASTS OF
MADAGASCAR OR OVER A SOUTHWARDS TURN. LATEST ECMWF ENSEMBLE
OUTPUT GIVE A STRONGER WEIGHT TO THE EASTWARDS SOLUTION. SO, IS THE
CURRENT RSMC FORECAST.
NOW, ENVIRONMENTAL CONDITIONS SHOULD CONTINUE TO BE GOOD WITH A
GOOD DIVERGENCE AND A VERY WEAK VERTICAL WINDSHEAR, BUT THE
PROXIMITY OF SOUTHERN COAST OF MADAGASCAR MIGHT CONTINUE TO INFLIC
THE SYSTEM.
MONDAY AND AFTER, ENVIRONMENTAL CONDITIONS ARE EXPECTED TO
DETERIORATE WITH A LESS GOOD UPPER LEVEL DIVERGENCE, A STRENGTHENING
WEST-NORTHWESTERLY SHEAR AND A LOW TO MID-LEVEL DRY AIR INTRUSION
FROM THE SOUTH-WEST ASSOCIATED TO A SURGE OF SUBTROPICAL HIGH
PRESSURE.
INHABITANTS OF SOUTHERN MALAGASY AREAS ARE INVITED TO CLOSELY
FOLLOW THE PROGRESS OF THIS SYSTEM. IF THE CURRENT FORECAST BRING THE
SYSTEM AT ABOUT 100 KM FROM THE COAST THIS EVENING, A LANDFALL IS NOT
TOTALLY EXCLUDED (MAINLY OVER COASTAL AREAS BETWEEN CAP SAINTEMARIE AND FORT-DAUPHIN) ON SATURDAY EVENING OR SUNDAY.
REGARDLESS OF THIS POTENTIAL LANDFALL, WEATHER CONDITIONS MIGHT
DETERIORATE OVER THIS AREA LATER TODAY OR TONIGHT WITH STRONG WINDS
(GUSTS UP TO 100 KM/H) AND HEAVY RAINS SPELLS.
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