TC 08S(DANILO) & Invest 93S: 370km apart, will merge in 36/48hours, still low confidence in the forecast track, 03/15utc update


OVER THE NEXT 24 TO 36 HOURS, 93S IS EXPECTED TO MOVE WEST TO THE SOUTH OF TC 08S THEN WRAP TOWARDS TC 08S, ULTIMATELY MERGING INTO ONE SYSTEM BETWEEN 36/48H. DURING THIS PROCESS TC 08S, AS THE DOMINATE OF THE TWO CIRCULATIONS, WILL SLOWLY TURN TO A MORE SOUTHWARD TRACK WHILE SLOWING DOWN IN RESPONSE BOTH TO THE INTERACTION WITH 93S AND MOVEMENT INTO A WEAK STEERING ENVIRONMENT.


OVER THE NEXT 24 TO 36 HOURS, 93S IS EXPECTED TO MOVE WEST TO  THE SOUTH OF TC 08S THEN WRAP TOWARDS TC 08S, ULTIMATELY MERGING INTO  ONE SYSTEM BETWEEN 36/48H. DURING THIS PROCESS TC 08S, AS THE  DOMINATE OF THE TWO CIRCULATIONS, WILL SLOWLY TURN TO A MORE SOUTHWARD  TRACK WHILE SLOWING DOWN IN RESPONSE BOTH TO THE INTERACTION WITH 93S  AND MOVEMENT INTO A WEAK STEERING ENVIRONMENT.
OVER THE NEXT 24 TO 36 HOURS, 93S IS EXPECTED TO MOVE WEST TO THE SOUTH OF TC 08S THEN WRAP TOWARDS TC 08S, ULTIMATELY MERGING INTO ONE SYSTEM BETWEEN 36/48H. DURING THIS PROCESS TC 08S, AS THE DOMINATE OF THE TWO CIRCULATIONS, WILL SLOWLY TURN TO A MORE SOUTHWARD TRACK WHILE SLOWING DOWN IN RESPONSE BOTH TO THE INTERACTION WITH 93S AND MOVEMENT INTO A WEAK STEERING ENVIRONMENT.
2021 JAN 03 1430UTC #SOUTHINDIANOCEAN
TC #08S #DANILO
WARNING 8
As of 12:00 UTC Jan 03, 2021:
Location: 12.3°S 74.2°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt ( 130km/h)
Minimum Central Pressure: 984 mb
Satellite bulletins are to be found in the comments of this post on JTWC BIS
REMARKS:
031500Z POSITION NEAR 12.6S 74.6E.
03JAN21. TROPICAL CYCLONE 08S (DANILO), LOCATED APPROXIMATELY 610
KM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTHEASTWARD AT
17 KM/H OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) DEPICTS DEEP CONVECTION FORMING A SYMMETRIC OVERCAST,
OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC). A 031117Z SSMI
COLOR 89GHZ MICROWAVE IMAGE SHOWS THE DEEPEST CONVECTION LIES IN THE
NORTHWESTERN QUADRANT WITH WEAKER CONVECTION WRAPPING INTO A WEAKLY
DEFINED MICROWAVE EYE FEATURE, LENDING HIGH CONFIDENCE TO THE INITIAL
POSITION. THE INITIAL INTENSITY IS ASSESSED AT 55 KNOTS WITH HIGH
CONFIDENCE BASED ON MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF
T3.5 (55 KTS) FROM BOTH PGTW AND FMEE, AND ADT ESTIMATE OF T3.5 AND A
SATELLITE CONSENSUS ESTIMATE OF 55 KNOTS. TC 08S CONTINUES TO TRACK
STEADILY TOWARDS THE SOUTHEAST ALONG THE WESTERN PERIPHERY OF A DEEP
NEAR EQUATORIAL RIDGE CENTERED FAR TO THE NORTHEAST. THE ENVIRONMENT
REMAINS FAVORABLE WITH WARM SSTS AND LOW VWS BEING OFFSET SLIGHTLY BY
MARGINAL OUTFLOW ALOFT. INVEST 93S IS CURRENTLY LOCATED APPROXIMATELY
200NM TO THE SOUTH-SOUTHEAST AND GLOBAL SEA LEVEL PRESSURE FIELDS
INDICATE THAT THE BINARY INTERACTION BETWEEN THE TWO SYSTEMS HAS
BEGUN. OVER THE NEXT 24 TO 36 HOURS, 93S IS EXPECTED TO MOVE WEST TO
THE SOUTH OF TC 08S THEN WRAP TOWARDS TC 08S, ULTIMATELY MERGING INTO
ONE SYSTEM BETWEEN TAUS 36 AND 48. DURING THIS PROCESS TC 08S, AS THE
DOMINATE OF THE TWO CIRCULATIONS, WILL SLOWLY TURN TO A MORE SOUTHWARD
TRACK WHILE SLOWING DOWN IN RESPONSE BOTH TO THE INTERACTION WITH 93S
AND MOVEMENT INTO A WEAK STEERING ENVIRONMENT IN THE COL REGION
BETWEEN THE NER TO THE NORTHEAST AND A DEVELOPING SUBTROPICAL RIDGE
(STR) TO THE SOUTHWEST. BY TAU 48 THE STR BUILDS IN SUFFICIENTLY TO
NUDGE TC 08S ONTO A WESTWARD TRACK AND AS THE STR BECOMES MORE
ENTRENCHED, WILL SUPPORT A WESTWARD TRACK THROUGH THE END OF THE
FORECAST PERIOD. DYNAMIC MODEL GUIDANCE HAS BECOME MORE UNCERTAIN
SINCE THE PREVIOUS RUNS, WITH THE CONSENSUS MEMBERS NOW DEPICTING A
WIDE RANGE OF POTENTIAL TRACKS. MOST OF THE GUIDANCE MEMBERS AGREE ON
THE OVERALL SCENARIO, WITH THE NOTABLE EXCEPTION OF COAMPS-TC (GFS)
AND GALWEM WHICH ARE NOW SHOWING A TURN TO THE EAST AND EVENTUAL LOOP
BACK TO THE NORTH. OF THE REMAINDER OF THE CONSENSUS MEMBERS, GFS HAS
DEVELOPED A DISTINCT EQUATORWARD TRACK AFTER THE TURN TO THE WEST. THE
JTWC FORECAST TRACK REMAINS CONSISTENT WITH PREVIOUS FORECASTS AND
CLOSELY TRACKS THE ECMWF SOLUTION, WHICH HAS BEEN THE MOST CONSISTENT
OF THE AVAILABLE GUIDANCE, WITH OVERALL LOW CONFIDENCE DUE TO THE
INCREASING UNCERTAINTY IN THE TRACK GUIDANCE. THERE IS ALSO A HIGH
DEGREE OF UNCERTAINTY IN THE INTENSITY FORECAST, THOUGH THE OVERALL
SPREAD IN THE INTENSITY GUIDANCE HAS DECREASED. THE JTWC INTENSITY
FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST AND IS NEAR THE
INTENSITY CONSENSUS THROUGH TAU 72, THEN SIGNIFICANTLY ABOVE IT
THROUGH TAU 120. HOWEVER, THE ULTIMATE TRACK WILL HAVE A LARGE IMPACT
ON THE INTENSITY AND DUE TO THE UNCERTAINTY PRESENT IN BOTH THE TRACK
AND INTENSITY GUIDANCE, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY
FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 031200Z IS 18 FEET. NEXT
WARNINGS AT 032100Z, 040300Z, 040900Z AND 041500Z.//
NNNN
-----------------------------------------
INVEST #93S
UPDATE
As of 12:00 UTC Jan 03, 2021:
Location: 15.3°S 76.0°E
Maximum Winds: 25 kt
Gusts: 35 kt
WEAKENING
Minimum Central Pressure: 1000 mb
LOW
Satellite bulletins are to be found in the comments of this post on JTWC BIS

03/14UTC. AT 12UTC INVEST 93S WAS LOCATED APPROXIMATELY  370KM TO THE SOUTH-SOUTHEAST OF TC 08S AND GLOBAL SEA LEVEL PRESSURE FIELDS  INDICATE THAT THE BINARY INTERACTION BETWEEN THE TWO SYSTEMS HAS  BEGUN.
03/14UTC. AT 12UTC INVEST 93S WAS LOCATED APPROXIMATELY 370KM TO THE SOUTH-SOUTHEAST OF TC 08S AND GLOBAL SEA LEVEL PRESSURE FIELDS INDICATE THAT THE BINARY INTERACTION BETWEEN THE TWO SYSTEMS HAS BEGUN.


MICROWAVE IMAGE SHOWS THE DEEPEST CONVECTION LIES IN THE NORTHWESTERN QUADRANT WITH WEAKER CONVECTION WRAPPING INTO A WEAKLY DEFINED MICROWAVE EYE FEATURE
MICROWAVE IMAGE SHOWS THE DEEPEST CONVECTION LIES IN THE NORTHWESTERN QUADRANT WITH WEAKER CONVECTION WRAPPING INTO A WEAKLY DEFINED MICROWAVE EYE FEATURE
Rédigé par PATRICK HOAREAU le Dimanche 3 Janvier 2021 à 18:58