24/09utc update: former STY 02W(SURIGAE) now subtropical, Invest 96P subtropical over the South Pacific, new burst of convection for 29S(JOBO) SE of Dar es Salaam


INVEST 96P. 24/0530UTC. SUBTROPICAL SYSTEM WITH 35KNOT WINDS JUST NORTH OF 30°SOUTH. CLICK TO ANIMATE.


INVEST 96P. 24/0530UTC. SUBTROPICAL SYSTEM WITH 35KNOT WINDS JUST NORTH OF 30°SOUTH. CLICK TO ANIMATE.
INVEST 96P. 24/0530UTC. SUBTROPICAL SYSTEM WITH 35KNOT WINDS JUST NORTH OF 30°SOUTH. CLICK TO ANIMATE.
2021 APR 24 0900UTC #WESTERNNORTHPACIFIC
SS #02W #SURIGAE
WARNING 44
As of 06:00 UTC Apr 24, 2021:
Location: 22.7°N 131.9°E
Maximum Winds: 45 kt (80km/h)
Minimum Central Pressure: 988 mb
SUBTROPICAL
LOCATED AT 24/06UTC APPROXIMATELY 985KM WEST-SOUTHWEST OF IWO TO, HAS TRACKED EAST-SOUTHEASTWARD AT 13
KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS
-----------------------------------------------------------------------------------------------------------
TC #29S #JOBO #SOUTHINDIANOCEAN
UPDATE
As of 06:00 UTC Apr 24, 2021:
Location: 7.9°S 40.5°E
Maximum Winds: 35 kt ( 65km/h)
Gusts: 45 kt ( 85km/h)
Minimum Central Pressure: 1005 mb
WEAKENING
LOCATED AT 24/06UTC APPROXIMATELY APPROXIMATELY 190KM SOUTHEAST OF DAR ES SALAAM, TANZANIA, HAS TRACKED WESTWARDAT 15 KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS
-----------------------------------------------------------------------------------------------------------------
INVEST #96P #SOUTPACIFICOCEAN
UPDATE
As of 06:00 UTC Apr 24, 2021:
Location: 29.0°S 142.2°W
Maximum Winds: 35 kt ( 65km/h)
Minimum Central Pressure: 1005 mb
SUBTROPICAL
LOCATED AT 24/00UTC APPROXIMATELY 1420 KM SOUTHEAST OF PAPEETE, FRENCH POLYNESIA.

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

Joint Typhoon Warning Center

02W(SURIGAE). WARNING 44 ISSUED AT 24/09UTC.ENVIRONMENTAL ANALYSIS REVEALS 02W IS EMBEDDED WITHIN THE  SUBTROPICAL WESTERLIES UNDER APPROXIMATELY 30-40 KNOTS OF WESTERLY  VERTICAL WIND SHEAR AND IS TRACKING OVER COOLER SST (24-25C). THE  SYSTEM IS ALSO ENTRAINING A DRY AIR MASS, PARTICULARLY IN THE  SOUTHWESTERN QUADRANT, AS EVIDENCED BY THE LACK OF ANY SIGNIFICANT  CONVECTIVE CLOUDS IN THIS QUADRANT. REGIONAL UPPER-AIR ANALYSIS  INDICATES ONE SHORTWAVE TROUGH EXITING THE REGION TO THE NORTHEAST,  WHILE ANOTHER, MUCH STRONGER MAJOR SHORTWAVE TROUGH, CURRENTLY  ENTERING THE FAR NORTHERN EAST CHINA SEA, IS RAPIDLY DIVING  SOUTHWARDS TOWARDS SURIGAE. THIS NEXT SHORTWAVE WILL BE THE ULTIMATE  TRIGGER FOR EXTRA-TROPICAL TRANSITION.OVER THE NEXT 36 HOURS, SS 02W IS FORECAST TO BEGIN  ACCELERATING TO THE EAST THEN NORTHEAST, TO THE SOUTH OF IWO TO, AS  IT COMES UNDER THE STEERING INFLUENCE OF THE STRONG MID-LATITUDE  WESTERLY FLOW. AS THE AFOREMENTIONED MAJOR SHORTWAVE TROUGH DIVES  SOUTHWARD THROUGH THE NEXT 24 HOURS, IT WILL INDUCING SIGNIFICANT  BAROCLINIC FORCING AND THERMAL ADVECTION, AND ULTIMATELY BRING ABOUT  TRANSITION TO A STRONG GALE-FORCE EXTRATROPICAL SYSTEM BY 36H.
02W(SURIGAE). WARNING 44 ISSUED AT 24/09UTC.ENVIRONMENTAL ANALYSIS REVEALS 02W IS EMBEDDED WITHIN THE SUBTROPICAL WESTERLIES UNDER APPROXIMATELY 30-40 KNOTS OF WESTERLY VERTICAL WIND SHEAR AND IS TRACKING OVER COOLER SST (24-25C). THE SYSTEM IS ALSO ENTRAINING A DRY AIR MASS, PARTICULARLY IN THE SOUTHWESTERN QUADRANT, AS EVIDENCED BY THE LACK OF ANY SIGNIFICANT CONVECTIVE CLOUDS IN THIS QUADRANT. REGIONAL UPPER-AIR ANALYSIS INDICATES ONE SHORTWAVE TROUGH EXITING THE REGION TO THE NORTHEAST, WHILE ANOTHER, MUCH STRONGER MAJOR SHORTWAVE TROUGH, CURRENTLY ENTERING THE FAR NORTHERN EAST CHINA SEA, IS RAPIDLY DIVING SOUTHWARDS TOWARDS SURIGAE. THIS NEXT SHORTWAVE WILL BE THE ULTIMATE TRIGGER FOR EXTRA-TROPICAL TRANSITION.OVER THE NEXT 36 HOURS, SS 02W IS FORECAST TO BEGIN ACCELERATING TO THE EAST THEN NORTHEAST, TO THE SOUTH OF IWO TO, AS IT COMES UNDER THE STEERING INFLUENCE OF THE STRONG MID-LATITUDE WESTERLY FLOW. AS THE AFOREMENTIONED MAJOR SHORTWAVE TROUGH DIVES SOUTHWARD THROUGH THE NEXT 24 HOURS, IT WILL INDUCING SIGNIFICANT BAROCLINIC FORCING AND THERMAL ADVECTION, AND ULTIMATELY BRING ABOUT TRANSITION TO A STRONG GALE-FORCE EXTRATROPICAL SYSTEM BY 36H.

02W(SURIGAE). THE JTWC FORECAST TRACK REMAINS CONSISTENT WITH THE PREVIOUS ONE.  NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH THE DURATION  OF THE FORECAST PERIOD WITH INCREASING ALONG-TRACK SPREAD AFTER 24H AS THE SYSTEM COMPLETES EXTRATROPICAL TRANSITION. OVERALL  CONFIDENCE IN THE JTWC FORECAST REMAINS HIGH.
02W(SURIGAE). THE JTWC FORECAST TRACK REMAINS CONSISTENT WITH THE PREVIOUS ONE. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH THE DURATION OF THE FORECAST PERIOD WITH INCREASING ALONG-TRACK SPREAD AFTER 24H AS THE SYSTEM COMPLETES EXTRATROPICAL TRANSITION. OVERALL CONFIDENCE IN THE JTWC FORECAST REMAINS HIGH.

02W(SURIGAE). 24/0656UTC.ANIMATED MULTISPECTRAL SATELLITE  IMAGERY (MSI) DEPICTS A BROAD, FULLY EXPOSED LOW LEVEL CIRCULATION  CENTER (LLCC), WITH DISORGANIZED CONVECTION FIRING IN THE UNSTABLE  EAST AND NORTHEAST QUADRANTS.
02W(SURIGAE). 24/0656UTC.ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD, FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC), WITH DISORGANIZED CONVECTION FIRING IN THE UNSTABLE EAST AND NORTHEAST QUADRANTS.


29S(JOBO). WARNING 8 ISSUED AT 24/09UTC.TC JOBO IS MOVING SLOWLY WEST-NORTHWESTWARD  ALONG THE NORTHERN PERIPHERY OF AN EAST-WEST ORIENTED LOW TO MID- LEVEL STR. THE OVERALL ENVIRONMENT REMAINS FAVORABLE, WITH LOW (10- 15KT) VWS, AND VERY WARM (29-30C) SSTS. THE MAIN HINDRANCE TO ANY  SIGNIFICANT DEVELOPMENT PRIOR TO LANDFALL IS THE PRESENCE OF A  REGION OF RELATIVELY DRIER AIR TO THE WEST, PROHIBITING THE RECENT  FLARING CONVECTION FROM EXPANDING AND PERSISTING. JOBO IS EXPECTED  TO MAKE LANDFALL JUST SOUTH OF DAR ES SALAAM WITHIN THE NEXT 12  HOURS AS A MINIMAL TROPICAL STORM, BEFORE MOVING RAPIDLY INLAND AND  QUICKLY DISSIPATING.
29S(JOBO). WARNING 8 ISSUED AT 24/09UTC.TC JOBO IS MOVING SLOWLY WEST-NORTHWESTWARD ALONG THE NORTHERN PERIPHERY OF AN EAST-WEST ORIENTED LOW TO MID- LEVEL STR. THE OVERALL ENVIRONMENT REMAINS FAVORABLE, WITH LOW (10- 15KT) VWS, AND VERY WARM (29-30C) SSTS. THE MAIN HINDRANCE TO ANY SIGNIFICANT DEVELOPMENT PRIOR TO LANDFALL IS THE PRESENCE OF A REGION OF RELATIVELY DRIER AIR TO THE WEST, PROHIBITING THE RECENT FLARING CONVECTION FROM EXPANDING AND PERSISTING. JOBO IS EXPECTED TO MAKE LANDFALL JUST SOUTH OF DAR ES SALAAM WITHIN THE NEXT 12 HOURS AS A MINIMAL TROPICAL STORM, BEFORE MOVING RAPIDLY INLAND AND QUICKLY DISSIPATING.

29S(JOBO).  NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT,  LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK.
29S(JOBO). NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK.

29S(JOBO). 24/0745UTC.ANIMATED MULTISPECTRAL  SATELLITE IMAGERY (MSI) SHOWS THAT DISORGANIZED CONVECTION HAS  FLARED UP OVER THE PAST SIX HOURS, REFORMING OVER AND JUST EAST OF  THE ASSESSED LOW LEVEL CENTER (LLC), INDICATIVE OF A SLIGHT  RELAXATION IN THE SHEAR ENVIRONMENT.
29S(JOBO). 24/0745UTC.ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THAT DISORGANIZED CONVECTION HAS FLARED UP OVER THE PAST SIX HOURS, REFORMING OVER AND JUST EAST OF THE ASSESSED LOW LEVEL CENTER (LLC), INDICATIVE OF A SLIGHT RELAXATION IN THE SHEAR ENVIRONMENT.

INVEST 96P. 24/0103UTC. THE SYSTEM IS  CURRENTLY CLASSIFIED AS A SUBTROPICAL STORM, GENERALLY CHARACTERIZED  AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED  ENHANCED INFRARED SATELLITE IMAGERY AND ANIMATED WATER VAPOR LOOP  INDICATES THE SYSTEM IS LOCATED DIRECTLY UNDER A BROAD UPPERLEVEL  COLD CORE LOW. A 240234Z SSMIS 91GHZ IMAGE REVEALS FORMATIVE, SPIRAL  BANDING WRAPPING INTO A LOW LEVEL CIRCULATION (LLC) WITH DEEP  CONVECTION IN THE NORTHWEST AND SOUTHEAST PERIPHERIES. ENVIRONMENTAL ANALYSIS FOR INVEST 96P INDICATES A HOSTILE ENVIRONMENT, NOT  CONDUCIVE FOR TROPICAL DEVELOPMENT DUE TO CONVERGENCE ALOFT AND COOL  (25-26 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL MODELS SHOW A  GENERAL SOUTHWARD TRACK WITH MINIMAL INTENSIFICATION OVER THE NEXT  24-36 HOURS.
INVEST 96P. 24/0103UTC. THE SYSTEM IS CURRENTLY CLASSIFIED AS A SUBTROPICAL STORM, GENERALLY CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND ANIMATED WATER VAPOR LOOP INDICATES THE SYSTEM IS LOCATED DIRECTLY UNDER A BROAD UPPERLEVEL COLD CORE LOW. A 240234Z SSMIS 91GHZ IMAGE REVEALS FORMATIVE, SPIRAL BANDING WRAPPING INTO A LOW LEVEL CIRCULATION (LLC) WITH DEEP CONVECTION IN THE NORTHWEST AND SOUTHEAST PERIPHERIES. ENVIRONMENTAL ANALYSIS FOR INVEST 96P INDICATES A HOSTILE ENVIRONMENT, NOT CONDUCIVE FOR TROPICAL DEVELOPMENT DUE TO CONVERGENCE ALOFT AND COOL (25-26 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL MODELS SHOW A GENERAL SOUTHWARD TRACK WITH MINIMAL INTENSIFICATION OVER THE NEXT 24-36 HOURS.

24/06UTC. THE JTWC IS ISSUING 6HOURLY WARNINGS ON 02W(SURIGAE) AND 12HOURLY WARNINGS ON 29S(JOBO). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. INVEST 96P(35KNOT SUSTAINED WINDS) IS ANALYZED AS A SUBTROPICAL SYSTEM HAVING LOW CHANCES OF TRANSITIONING INTO A TROPICAL SYSTEM.
24/06UTC. THE JTWC IS ISSUING 6HOURLY WARNINGS ON 02W(SURIGAE) AND 12HOURLY WARNINGS ON 29S(JOBO). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. INVEST 96P(35KNOT SUSTAINED WINDS) IS ANALYZED AS A SUBTROPICAL SYSTEM HAVING LOW CHANCES OF TRANSITIONING INTO A TROPICAL SYSTEM.
Rédigé par PATRICK HOAREAU le Samedi 24 Avril 2021 à 13:35