SIO: GAEL - Severe Tropical Storm - Discussion

[wyq614]

EC has ever had it strike directly La Réunion at an intensity of around 100kts in days. That is worth noting...

[Crostorm]

[Crostorm]

[Crostorm]

ECMWF forecast
http://www.ecmwf.int/products/forecasts ... 9013012!!/

[Crostorm]

[Crostorm]

[HURAKAN]

[Fadil]

[HURAKAN]

AN AREA OF CONVECTION HAS PERSISTED NEAR 15.1S 69.8E,
APPROXIMATELY 890 NM EAST-NORTHEAST OF LA REUNION ISLAND. ANIMATED
INFRARED SATELLITE IMAGERY AND A 312137Z AMSR-E IMAGE CONTINUE TO
DEPICT POORLY ORGANIZED CONVECTION FLARING AROUND THE PERIPHERY OF
THE LOW-LEVEL CIRCULATION CENTER (LLCC). HOWEVER, A 311642Z ASCAT
IMAGE INDICATES A STRENGTHENING, WELL-DEFINED LLCC WITH 20-25 KNOT
UNFLAGGED WINDS. THE ENVIRONMENT HAS IMPROVED OVER THE PAST 24 HOURS
AS THE SYSTEM TRACKED SOUTHWESTWARD UNDER THE UPPER-LEVEL RIDGE WITH
A DEVELOPING ANTICYCLONE NOW EVIDENT OVER THE CENTER. EQUATORWARD
OUTFLOW HAS IMPROVED AND POLEWARD OUTFLOW SHOULD CONTINUE TO IMPROVE
AS THE SYSTEM BEGINS TO TAP INTO MIDLATITUDE WESTERLIES JUST SOUTH
WITHIN THE NEXT 24 HOURS. THE SST (28C), OCEAN HEAT CONTENT AND
TOTAL PRECIPITABLE WATER ARE ALSO FAVORABLE FOR FURTHER DEVELOPMENT.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS POOR.

[Chacor]

WTIO30 FMEE 011233

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 1/8/20082009
1.A ZONE OF DISTURBED WEATHER 8

2.A POSITION 2009/02/01 AT 1200 UTC :
15.1S / 70.4E
(FIFTEEN DECIMAL ONE DEGREES SOUTH AND SEVENTY DECIMAL FOUR DEGREES EAST)
MOVEMENT : SOUTH-SOUTH-WEST 4 KT

3.A DVORAK ANALYSIS : 1.5/1.5 /D
4.A CENTRAL PRESSURE : 1007 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 20 KT
RADIUS OF MAXIMUM WINDS (RMW) : NIL

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


7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS:
12H: 2009/02/02 00 UTC: 15.4S/69.6E, MAX WIND=020KT, TROP. DISTURBANCE.
24H: 2009/02/02 12 UTC: 15.4S/68.8E, MAX WIND=025KT, TROP. DISTURBANCE.
36H: 2009/02/03 00 UTC: 15.6S/67.7E, MAX WIND=030KT, TROP. DEPRESSION.
48H: 2009/02/03 12 UTC: 15.9S/66.7E, MAX WIND=040KT, MODERATE TROP. STORM
..
60H: 2009/02/04 00 UTC: 16.4S/65.5E, MAX WIND=050KT, SEVERE TROP. STORM.
72H: 2009/02/04 12 UTC: 16.9S/63.6E, MAX WIND=060KT, SEVERE TROP. STORM.

2.B OTHER INFORMATIONS:
ENVIRONNENTAL CONDITIONS ARE GLOBALLY NEUTRAL. LOCATED ON THE EDGE OF THE
UPPER LEVEL RIDGE, THE SYSTEM IS ALWAYS UNDERGOING A WEAK TO MORERATE
EASTERLY VERTICAL WINDS SHEAR, AND THE LOW IS ONLY FED BY MOONSON INFLOW.
CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLES BEYOND TAU 24H, DUE TO
IMPROVING
FEEDING BY A BETTER MOONSON FLOW AND THE BUILD OF SUBTROPICAL HIGH
PRESSURES. VERTICAL WINDS SHEAR SHOULD WEAKEN.

ALL AVAILABLE NPW TRACK IT WESTWARDS OR WESTSOUTHWESTWARDS, INTENSIFYING
IT UNDER THE INFLUENCE OF THE REBUILT SUBTROPICAL RIDGE INTHE SOUTHEAST.
THERE ARE TWO MAIN SENARII, DEPENDING ON THE SPEED OF INTENSIFICATION,
AND THE EXPENSION OF THE REIDGE WESTWARDS IN THE SOUTH OF THE SYSTEMN AND
NORTHWARDS IN THE EAST OF THE SYSYTEM.

CURRENT FORECAST IS BASED ON A CONSENSUS OF CEP, UKMO AND CONW MODELS,
WITH A MORE PROGRESSIVE INTENSIFICATION AND A RIDGE STRONGER IN THE SOUTH
OF THE SYSTEM

AT THIS STAGE OF INTENSITY, SYSTEM DOES NOT JUSTIFY ISSUANCE OG REGULAR
WARNINGS.

[HURAKAN]

[HURAKAN]

[Crostorm]

[HURAKAN]

[HURAKAN]

[HURAKAN]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.2S 69.9E
IS NOW LOCATED NEAR 15.6S 69.1E, APPROXIMATELY 835 NM EAST-NORTHEAST
OF LA REUNION ISLAND. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS
A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH FORMATIVE
CONVECTIVE BANDING OVER THE WESTERN SEMI-CIRCLE. A 012109Z AMSU 89GHZ
IMAGE SHOWED AN IMPROVED LLCC WITH DEEP CONVECTION WRAPPING INTO
THE NORTHERN QUADRANT. OVERALL, THE ENVIRONMENT IS FAVORABLE FOR
FURTHER DEVELOMENT WITH THE EXCEPTION OF MODERATE VERTICAL WIND
SHEAR (VWS). THERE IS A DEVELOPING ANTICYCLONE NEAR THE CENTER WITH
IMPROVED RADIAL OUTFLOW. THE SST (28C), OCEAN HEAT CONTENT AND TOTAL
PRECIPITABLE WATER CONTINUE TO FAVOR DEVELOPMENT. AN UPPER-LEVEL
SHORTWAVE TROUGH IS FORECAST TO TRACK SOUTHWEST OF THE SYSTEM BY
TAU 24 AND WILL FURTHER ENHANCE POLEWARD OUTFLOW. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. BASED ON THE IMPROVED
CONSOLIDATION AND OUTFLOW, THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS
UPGRADED TO FAIR.

[HURAKAN]

[HURAKAN]

406
WTIO30 FMEE 020622

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 2/8/20082009
1.A TROPICAL DISTURBANCE 8

2.A POSITION 2009/02/02 AT 0600 UTC :
WITHIN 30 NM RADIUS OF POINT 15.6S / 68.3E
(FIFTEEN DECIMAL SIX DEGREES SOUTH AND SIXTY EIGHT DECIMAL THREE DEGREES
EAST)
MOVEMENT : WEST-SOUTH-WEST 7 KT

3.A DVORAK ANALYSIS : 2.0/2.0 /D 0.5/18 H
4.A CENTRAL PRESSURE : 1005 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 20 KT
RADIUS OF MAXIMUM WINDS (RMW) : NIL

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


7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS:
12H: 2009/02/02 18 UTC: 15.8S/67.4E, MAX WIND=025KT, TROP. DISTURBANCE.
24H: 2009/02/03 06 UTC: 16.3S/66.0E, MAX WIND=030KT, TROP. DEPRESSION.
36H: 2009/02/03 18 UTC: 16.8S/64.0E, MAX WIND=035KT, MODERATE TROP. STORM
..
48H: 2009/02/04 06 UTC: 17.4S/62.1E, MAX WIND=040KT, MODERATE TROP. STORM
..
60H: 2009/02/04 18 UTC: 17.8S/60.2E, MAX WIND=050KT, SEVERE TROP. STORM.
72H: 2009/02/05 06 UTC: 18.1S/58.2E, MAX WIND=060KT, SEVERE TROP. STORM.

2.B OTHER INFORMATIONS:
T=CI=2.0-

SYSTEM IS SHEARED WITH AN ILL-DEFINED LOW LEVEL CIRCULATION LOCATED EAST
OF THE MAIN CONVECTION.
ENVIRONNENTAL CONDITIONS ARE GLOBALLY NEUTRAL. LOCATED ON THE EDGE OF THE
UPPER LEVEL RIDGE, THE SYSTEM IS ALWAYS UNDERGOING A WEAK TO MORERATE
VERTICAL WINDS SHEAR AND THE LOW LEVEL IS ONLY FED BY MOONSON INFLOW AT
THIS TIME.
TOMORROW ALONG THE DAY,CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE
DUE TO IMPROVING FEEDING BY A BETTER MONSOON FLOW AND THE BUILD OF
SUBTROPICAL HIGH PRESSURES. SYSTEM SHOULD PROGRESSIVELY BE MORE UNDER THE
UPPER LEVEL RIDGE WITH A DECREASING VERTICAL WINDSHEAR.

12Z AND EARLIER 00Z NWP MODELS TRACK THE WESTWARDS OR WESTSOUTHWESTWARDS,
ON THE NORTHERN EDGE OF REBUILDING SUBTROPICAL RIDGE. MAIN DIFFERENCE
WITH THE 00Z RUN OF YESTERDAY IS THE FASTER MOTION. THIS IS REFLECTED IN
THE PRESENT FORECAST.

CURRENT FORECAST TRACK IS BASED ON A CONSENSUS OF CEP, UKMO AND A
CONSENSUS OF US MODELS.

INTENSIFICATION RATE IS SLOW FOR THE NEXT 48 HOURS AND THEN AT A
CLIMATOLOGICAL RATE.

INTEREST IN THE MASCAREGNAS ISLANDS SHOULD CLOSELY MONITOR THE PROGRESS
OF THIS SYSTEM.

[HURAKAN]

02/0230 UTC 15.1S 67.9E T2.0/2.0 93S -- Southwest Indian

[HURAKAN]

Shear still a problem.