SOUTH INDIAN: Invest 99S is now TC 26S: forecast to reach US/CAT 2 by 72hours. Invest 90S is up-graded to High and intensifying, 04/15utc update


04/15UTC. 9H ANIMATION. TC 26S ON THE RIGHT AND INVEST 90S. CICK TO ANIMATE IF NECESSARY.


04/15UTC. 9H ANIMATION. TC 26S ON THE RIGHT AND INVEST 90S. CICK TO ANIMATE IF NECESSARY.
04/15UTC. 9H ANIMATION. TC 26S ON THE RIGHT AND INVEST 90S. CICK TO ANIMATE IF NECESSARY.
2021 APR 04 1415UTC #SOUTHINDIANOCEAN
TC #26S #SOUTHERNHEMISPHERE #WESTERNAUSTRALIA
WARNING 1
As of 12:00 UTC Apr 04, 2021:
Location: 10.4°S 123.2°E
Maximum Winds: 35 kt ( 65km/h)
Gusts: 45 kt ( 85km/h)
Minimum Central Pressure: 999 mb
INTENSIFYING
TC 26S LOCATED AT 04/12UTC APPROXIMATELY 840 KM NORTH OF BROOME, AUSTRALIA, HAS TRACKED WEST-SOUTHWESTWARD
AT 15 KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS
----------------------------------------------------------
INVEST #90S #SOUTHERNHEMISPHERE #WESTERNAUSTRALIA
UPDATE/TCFA
As of 12:00 UTC Apr 04, 2021:
Location: 14.6°S 104.9°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)
Minimum Central Pressure: 1003 mb
INTENSIFYING
LOCATED AT 04/12UTC APPROXIMATELY 470KM SOUTH-SOUTHWEST OF CHRISTMAS ISLAND.
CURRENT POTENTIAL FOR THE NEXT 24HOURS: UP-GRADED TO HIGH.
Satellite bulletins are to be found in the comments of this post on JTWC BIS

Cheers,
Patrick Hoareau
M974World
ILES SOEURS
Cyclone Class 4
 Cheers,PH.

Joint Typhoon Warning Center

TC 26S. WARNING 1 ISSUED AT 04/15UTC. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM RESIDES EQUATORWARD OF THE SUBTROPICAL RIDGE (STR) WITH GOOD  RADIAL OUTFLOW ALOFT, ENVELOPED IN A SMALL REGION OF LOW TO MODERATE  (10-15 KNOTS) VERTICAL WIND SHEAR, AND WARM SEA SURFACE  TEMPERATURES (28-30C). TC 26S CURRENTLY RESIDES IN A VERY WEAK  STEERING ENVIRONMENT AND WILL BEGIN MOVING SOUTHWESTWARD AS A RIDGE  BUILDS IN FROM THE SOUTHEAST THROUGH THE REMAINDER OF THE FORECAST.  AS THE SYSTEM MOVES SOUTHWEST, AN INCREASE IN POLEWARD OUTFLOW WILL  ENHANCE THE INTENSIFICATION TO A PEAK STRENGTH OF 85 KNOTS/US CATEGORY 2 BY 72H. DURING THIS TIMEFRAME, BINARY INTERACTION WITH INVEST 90S IS  LIKELY, THE TWO SYSTEMS REMAINING NEARLY 925KM APART BY SOME MODEL  ESTIMATES. THIS INTERACTION WILL CREATE A DYNAMIC CHANGE TO TC 26S  INTENSIFICATION AND TRACK MOTION, ADDING INHERENT UNCERTAINTY.
TC 26S. WARNING 1 ISSUED AT 04/15UTC. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM RESIDES EQUATORWARD OF THE SUBTROPICAL RIDGE (STR) WITH GOOD RADIAL OUTFLOW ALOFT, ENVELOPED IN A SMALL REGION OF LOW TO MODERATE (10-15 KNOTS) VERTICAL WIND SHEAR, AND WARM SEA SURFACE TEMPERATURES (28-30C). TC 26S CURRENTLY RESIDES IN A VERY WEAK STEERING ENVIRONMENT AND WILL BEGIN MOVING SOUTHWESTWARD AS A RIDGE BUILDS IN FROM THE SOUTHEAST THROUGH THE REMAINDER OF THE FORECAST. AS THE SYSTEM MOVES SOUTHWEST, AN INCREASE IN POLEWARD OUTFLOW WILL ENHANCE THE INTENSIFICATION TO A PEAK STRENGTH OF 85 KNOTS/US CATEGORY 2 BY 72H. DURING THIS TIMEFRAME, BINARY INTERACTION WITH INVEST 90S IS LIKELY, THE TWO SYSTEMS REMAINING NEARLY 925KM APART BY SOME MODEL ESTIMATES. THIS INTERACTION WILL CREATE A DYNAMIC CHANGE TO TC 26S INTENSIFICATION AND TRACK MOTION, ADDING INHERENT UNCERTAINTY.

TC 26S. NUMERICAL MODELS ARE IN FAIR AGREEMENT DURING THE NEAR TERM WITH  ALONG AND CROSS TRACK ERROR OF 95KNM OUT TO 24H. HOWEVER, DUE TO  THE AFOREMENTIONED INTERACTION WITH INVEST 90S, THE SPREAD CONTINUES  TO DIVERGE TO 1170NM BY 120H. THE SPREAD IN MODEL TRACK GUIDANCE  LENDS LOW CONFIDENCE IN THE OVERALL JTWC TRACK FORECAST, CURRENTLY  LAID SLIGHTLY RIGHT OF CONSENSUS, FAVORING THE ECMWF AND NAVGEM  MODELING GUIDANCE OVER THE LEFT OUTLIERS OF GFS AND AFUM.
TC 26S. NUMERICAL MODELS ARE IN FAIR AGREEMENT DURING THE NEAR TERM WITH ALONG AND CROSS TRACK ERROR OF 95KNM OUT TO 24H. HOWEVER, DUE TO THE AFOREMENTIONED INTERACTION WITH INVEST 90S, THE SPREAD CONTINUES TO DIVERGE TO 1170NM BY 120H. THE SPREAD IN MODEL TRACK GUIDANCE LENDS LOW CONFIDENCE IN THE OVERALL JTWC TRACK FORECAST, CURRENTLY LAID SLIGHTLY RIGHT OF CONSENSUS, FAVORING THE ECMWF AND NAVGEM MODELING GUIDANCE OVER THE LEFT OUTLIERS OF GFS AND AFUM.


TC 26S. 04/1430UTC. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A BROAD SYSTEM CONSOLIDATING WITH  FORMATIVE BANDS WRAPPING TIGHTER INTO A LOW LEVEL CIRCULATION CENTER  OVER THE SAVU SEA.
TC 26S. 04/1430UTC. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A BROAD SYSTEM CONSOLIDATING WITH FORMATIVE BANDS WRAPPING TIGHTER INTO A LOW LEVEL CIRCULATION CENTER OVER THE SAVU SEA.

TC 26S. 04/1041UTC. MICROWACE DEPITS A BROAD SYSTEM CONSOLIDATING WITH  FORMATIVE BANDS WRAPPING TIGHTER INTO THE CENTER.
TC 26S. 04/1041UTC. MICROWACE DEPITS A BROAD SYSTEM CONSOLIDATING WITH FORMATIVE BANDS WRAPPING TIGHTER INTO THE CENTER.

INVEST 90S. TROPICAL CYCLONE FORMATION ALERT ISSUED AT 04/08UTC. HIGH CHANCES OF HAVING SUSTAINED WINDS REACHING 35KNOTS CLOSE TO THE CENTER WITHIN 24HOURS.
INVEST 90S. TROPICAL CYCLONE FORMATION ALERT ISSUED AT 04/08UTC. HIGH CHANCES OF HAVING SUSTAINED WINDS REACHING 35KNOTS CLOSE TO THE CENTER WITHIN 24HOURS.

INVEST 90S. 90S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH WARM (30 CELSIUS) SEA SURFACE TEMPERATURES AND  LOW (5 TO 10 KNOTS) VERTICAL WIND SHEAR, AND EXCELLENT POLEWARD OUTFLOW;  HOWEVER, THE HIGH TRACK SPEEDS MAY BE SLIGHTLY OFFSETTING THE  ENVIRONMENTAL FACTORS. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 90S  WILL REMAIN ELONGATED AND ASYMMETRIC AS IT TRACKS SOUTHEAST AND  INTENSIFIES, REACHING WARNING THRESHOLD WITHIN 36 HOURS.
INVEST 90S. 90S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH WARM (30 CELSIUS) SEA SURFACE TEMPERATURES AND LOW (5 TO 10 KNOTS) VERTICAL WIND SHEAR, AND EXCELLENT POLEWARD OUTFLOW; HOWEVER, THE HIGH TRACK SPEEDS MAY BE SLIGHTLY OFFSETTING THE ENVIRONMENTAL FACTORS. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 90S WILL REMAIN ELONGATED AND ASYMMETRIC AS IT TRACKS SOUTHEAST AND INTENSIFIES, REACHING WARNING THRESHOLD WITHIN 36 HOURS.

INVEST 90S. 04/1425UTC. ASCAT-B READ 35KNOT WINDS IN THE SOUTHERN QUADRANT.
INVEST 90S. 04/1425UTC. ASCAT-B READ 35KNOT WINDS IN THE SOUTHERN QUADRANT.

04/15UTC. INVEST 99S IS NOW TC 26S WITH 35KNOT WINDS. INVEST 90S WAS UP-GRADED TO HIGH AT 04/08UTC. JTWC IS ISSUING 6 HOURLY WARNINGS ON 26S AND 3HOURLY SATELLITE BULLETINS ON BOTH SYSTEMS.
04/15UTC. INVEST 99S IS NOW TC 26S WITH 35KNOT WINDS. INVEST 90S WAS UP-GRADED TO HIGH AT 04/08UTC. JTWC IS ISSUING 6 HOURLY WARNINGS ON 26S AND 3HOURLY SATELLITE BULLETINS ON BOTH SYSTEMS.
Rédigé par PATRICK HOAREAU le Dimanche 4 Avril 2021 à 19:50