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Tropical Storm Joalane Set To Become Cyclone

Tropical Storm Joalane Set To Become Cyclone

tropical storm joalane forecast

Some tropical news closer to home this week with the development of Tropical Storm Joalane, which is currently at Severe Tropical Storm strength to the east of Madagascar. Joalane has been steadily strengthening over the past few days as it’s moved slowly to the west. Current forecasts suggest that Joalane will become a Tropical Cyclone within the next 12 hours and reach Intense Tropical Cyclone status by 48 hours.

With a 1008mb low pressure system located off the South African east coast, moving east, Joalene will likely be pulled south by this weakness and so a change in track is expected. An almost completely southern movement is expected soon. Joalane’s current forecast will bring her close to Rodrigues Island on the 11th of April as an Intense Tropical Cyclone. Shortly after passing the island, the storm is expected to encounter increasingly hostile conditions and is set to weaken back to Tropical Cyclone status.

synoptic map joalane

Because of how far east the storm formed, in combination with the low pressure system that will be pulling it poleward, it’s highly unlikely that Joalane will have any direct effect on the weather in South Africa.

Forecast from La Reunion at time of publication:

ZCZC 912
WTIO30 FMEE 070105
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 10/13/20142015
1.A SEVERE TROPICAL STORM 13 (JOALANE)
2.A POSITION 2015/04/07 AT 0000 UTC:
WITHIN 20 NM RADIUS OF POINT 13.9 S / 62.4 E
(THIRTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY TWO DECIMAL
FOUR DEGREES EAST)
MOVEMENT : EAST 4 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 1.0/24 H
4.A CENTRAL PRESSURE: 990 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT
RADIUS OF MAXIMUM WINDS (RMW) :46 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 190 SE: 220 SW: 150 NW: 130
34 KT NE: 140 SE: 170 SW: 120 NW: 110
48 KT NE: 60 SE: 60 SW: 60 NW: 0
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1100 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2015/04/07 12 UTC: 14.3 S / 62.2 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
24H: 2015/04/08 00 UTC: 14.8 S / 62.0 E, MAX WIND=070 KT, TROPICAL CYCLONE
36H: 2015/04/08 12 UTC: 15.5 S / 61.9 E, MAX WIND=085 KT, TROPICAL CYCLONE
48H: 2015/04/09 00 UTC: 16.2 S / 62.0 E, MAX WIND=100 KT, INTENSE TROPICAL CYCLONE
60H: 2015/04/09 12 UTC: 17.0 S / 62.3 E, MAX WIND=105 KT, INTENSE TROPICAL CYCLONE
72H: 2015/04/10 00 UTC: 17.8 S / 62.8 E, MAX WIND=110 KT, INTENSE TROPICAL CYCLONE
2.B LONGER-RANGE OUTLOOK :
96H: 2015/04/11 00 UTC: 19.6 S / 64.0 E, MAX WIND=105 KT, INTENSE TROPICAL CYCLONE
120H: 2015/04/12 00 UTC: 22.4 S / 63.3 E, MAX WIND=080 KT, TROPICAL CYCLONE
2.C ADDITIONAL INFORMATIONS:
T=CI=3.0+
THE CLOUD PATTERN HAS CONTINUED TO IMPROVE OVERNIGHT. ON THE LATEST
IMAGE, A CURVED BAND WRAPS AT 0.8AO AROUND THE CENTER (DT AT 3.5). FT
IS RETAINED AT 3.0 DUE TO CONSTRAINT. THE ANALYZED INTENSITY IS ABOVE
DVORAK ESTIMATES AND IS BASED ON SATCON AT 2218Z (MADE WITH AN AMSU
ESTIMATE FROM A GOOD N19 PASS) AT 58 KT (1 MIN WIND).
JOALANE IS EMBEDDED WITHIN TWO CONTRADICTORY STEERING FLOW: ONE FROM
THE NORTH-WEST ASSOCIATED WITH THE NEAR EQUATORIAL RIDGE AND ANOTHER
FROM THE EAST STEERED BY A STR LOCATED NEAR 25S/60E. THE NEAR
EQUATORIAL STEERING FLOW SEEMS A BIT STRONGER CURRENTLY AS A SMALL
EASTWARDS DRIFT OF THE CENTER HAS TAKEN PLACE SINCE 18Z.
WITHIN THE NEXT FEW DAYS, A LARGE BAROMETRIC COL SHOULD GRADUALLY
MOVE SOUTH OF JOALANE (SOUTH OF 25S) AND THE MID-LEVEL HIGHS SHOULD
SHIFT ALONG A MERIDIAN AXIS LOCATED BETWEEN 70E AND 75E. THIS
SYNOPTIC PATTERN SHOULD FAVOR A POLEWARDS TRACK OF JOALANE WITHIN A
NORTHERLY TO NORTHWESTERLY STEERING FLOW.
SINCE THE PREVIOUS FORECAST, MAJOR CHANGES HAS OCCURRED IN THE
FORECAST TRACK: THE 3 MOST RELIABLE MODELS (GFS, EURO AND UKMO) ARE
NOW ON A CLEAR BETTER AGREEMENT TOWARDS A SOLUTION SHOWN BY GFS SINCE
MANY RUNS NOW … WITH A SOUTHWARDS TURN THAT SHOULD OCCUR EAST OF
60E AND A SOUTHWARDS TO SOUTHEASTWARDS TRACK POTENTIALLY VERY
DANGEROUS FOR RODRIGUES ISLAND ..
THE CURRENT TRACK IS CLOSE TO THE CONSENSUS OF THIS THREE MODELS
(MORE TO THE EAST FOR THE FIRST TWO DAYS AS THOSE MODELS STILL
ANALYSED THE SYSTEM TOO MUCH WEST). THE MULTI MODEL ENSEMBLE COMPOSED
BY THE ENSEMBLE FORECAST FROM ECMWF (EPS), GFS (GEFS) AND UKMO
(MOGREPS) FROM THE 12Z RUN, SHOW INCREASING PROBABILITIES AROUND THE
CURRENT EXPECTED SCENARIO COMPARED TO THE PREVIOUS RUN.
THE ENVIRONMENTAL CONDITIONS AROUND JOALANE BECOMES INCREASINGLY
FAVORABLE : THE SYSTEM MOVES GRADUALLY UNDER THE UPPER LEVEL RIDGE,
WITH GOOD EQUATORWARD DIVERGENCE AND IMPROVING OUTFLOW ELSEWHERE (THE
MAIN OUTFLOW CHANNEL SHOULD SHIFT TO THE SOUTH-EAST THURSDAY). SST
ARE CONDUCIVE.
ATMOSPHERIC AND OCEANIC CONDITIONS APPEAR FAVORABLE … AND JOALANE
IS EXPECTED TO BECOME A POWERFUL AND DANGEROUS CYCLONE LATER THIS
WEEK .. THEREFORE, RODRIGUES INHABITANTS SHOULD MONITOR THE PROGRESS
OF THIS SYSTEM.=

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