TC 08S(DANILO) is expected to make a sharp turn westward in 72h but confidence in the forecast remains low


TC 08S IS FORECAST TO REMAIN AT 55 KNOTS THROUGH 12H, BUT WEAKEN TO 45 KNOTS BY 48H AS THE CORE IS DISRUPTED BY INTERACTION AND ULTIMATE ABSORBTION OF INVEST 93S. AFTER THE SYSTEM REFORMS AND BEGINS TO MOVE WEST, THE UPPER-LEVEL ENVIRONMENT IS EXPECTED TO IMPROVE ALLOWING FOR STEADY INTENSIFICATION THROUGH 120H.


TC 08S IS FORECAST TO REMAIN AT 55 KNOTS THROUGH 12H,  BUT WEAKEN TO 45 KNOTS BY 48H AS THE CORE IS DISRUPTED BY  INTERACTION AND ULTIMATE ABSORBTION OF INVEST 93S. AFTER THE SYSTEM  REFORMS AND BEGINS TO MOVE WEST, THE UPPER-LEVEL ENVIRONMENT IS  EXPECTED TO IMPROVE ALLOWING FOR STEADY INTENSIFICATION THROUGH 120H.
TC 08S IS FORECAST TO REMAIN AT 55 KNOTS THROUGH 12H, BUT WEAKEN TO 45 KNOTS BY 48H AS THE CORE IS DISRUPTED BY INTERACTION AND ULTIMATE ABSORBTION OF INVEST 93S. AFTER THE SYSTEM REFORMS AND BEGINS TO MOVE WEST, THE UPPER-LEVEL ENVIRONMENT IS EXPECTED TO IMPROVE ALLOWING FOR STEADY INTENSIFICATION THROUGH 120H.
TC #08S #DANILO #SOUTHINDIANOCEAN
WARNING 7
As of 06:00 UTC Jan 03, 2021:
Location: 11.7°S 73.5°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt ( 130km/h)
Minimum Central Pressure: 987 mb
Satellite bulletins are to be found in the comments of this post on JTWC BIS
REMARKS:
030900Z POSITION NEAR 12.0S 73.9E.
03JAN21. TROPICAL CYCLONE 08S (DANILO), LOCATED APPROXIMATELY 282
NM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED EAST-
SOUTHEASTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-
SPECTRAL SATELLITE IMAGERY (MSI) DEPICTS FLARING DEEP CONVECTION TO
THE NORTH OF THE ASSESSED LOW-LEVEL CIRCULATION CENTER (LLCC), WITH
A SHARP EASTERN EDGE OF THE CONVECTIVE BLOWOFF, INDICATIVE OF
EASTERLY WIND SHEAR ALOFT. A BROAD EYE-LIKE FEATURE WITH MODERATE
CONVECTION TO THE NORTH AND WEAKER CONVECTION TO THE SOUTH IN A
030455Z AMSU-B 89GHZ MICRWAVE IMAGE, AS WELL AS A 030457Z ASCAT-B
SCATTEROMETER PASS, PROVIDED 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 PGTW AND FMEE, AN ADT ESTIMATE OF T3.3 (52
KTS) AND THE PREVIOUSLY MENTIONED ASCAT-B PASS, WHICH SHOWED A SMALL
AREA OF 50-55 KNOT WINDS TO THE NORTHEAST OF THE LLCC. ENVIRONMENTAL
ANALYSIS SHOWS THAT THE SYSTEM LIES IN A GENERALLY FAVORABLE
ENVIRONMENT CHARACTERIZED BY WARM (29-30 DEG C) SSTS, AND MODERATE
(15-20 KTS) VWS, BUT RESTRICTED SOMEWHAT BY A MARGINAL OUTFLOW
ENVIRONMENT WITH NO DISTINCT OUTFLOW CHANNEL AND SOME EASTERLY
PRESSURE FROM A WEAK UPPER-LEVEL ANTICYLCONE TO THE SOUTEAST NEAR
INVEST 93S IMPINGING ON THE SOUTHEAST SIDE OF TC 08S. THE SYSTEM IS
CURRENTLY TRACKING SOUTHEASTWARD UNDER THE STEERING INFLUENCE OF A
DEEP-LAYER NEAR EQUATORIAL RIDGE (NER) TO THE NORTHEAST, AND THIS
MOTION IS FORECAST TO CONTINUE THROUGH TAU 36. DURING THIS
TIMEFRAME, INVEST 93S, APPROXIMATELY 260NM TO THE SOUTHEAST, WILL
TRACK WEST TO THE SOUTH OF TC 08S. AFTER TAU 36 HOWEVER, INVEST 93S
WILL BEGIN TO FUJIWHARA WITH TC 08S AND TRACK NORTHWARDS AROUND THE
WESTERN PERIPHERY OF TC 08S WHICH, WHEN COMBINED BY A WEAKENING OF
THE STEERING ENVIRONMENT, WILL RESULT IN A DRASTIC REDUCTION IN
FORWARD SPEED OF TC 08S. INVEST 93S IS EXPECTED TO BE FULLY ABSORBED
BY TC 08S BY TAU 48. SIMULTANEOUSLY, THE STEERING ENVIRONMENT IS
MODIFIED BY THE DEVELOPMENT OF A STRONG SUBTROPICAL RIDGE (STR) TO
THE SOUTH, RESULTING IN A SHARP TURN WESTWARD BY TAU 72. TC 08S IS
THEN FORECAST TO CONTINUE TRACKING WESTWARD THROUGH THE REMAINDER OF
THE FORECAST PERIOD. NUMERICAL MODEL GUIDANCE REMAINS IN GENERAL
AGREEMENT ON THE OVERALL SCENARIO BUT WITH SIGNIFICANT DIFFERENCES
IN THE TIMING AND DEGREE OF THE TURN TO THE WEST. IN LIGHT OF THE
RECENT MOTION, THE FORECAST TRACK HAS BEEN PUSHED A BIT TO THE EAST
AND SOUTH WHILE RETAINING THE OVERALL TRACK SCENARIO. THE GFS AND
HWRF REMAIN THE EASTERN OUTLIERS WHILE NAVGEM IS THE WESTERNMOST OF
THE TRACKERS THROUGH TAU 72, THEN THE POLEWARD OUTLIER THEREAFTER.
THE JTWC FORECAST TRACK LIES CLOSE TO THE ECMWF SOLUTION, BUT, IN
LIGHT OF THE OVERALL UNCERTAINY IN THE GUIDANCE, IS PLACED WITH LOW
CONFIDENCE. TC 08S IS FORECAST TO REMAIN AT 55 KNOTS THROUGH TAU 12,
BUT WEAKEN TO 45 KNOTS BY TAU 48 AS THE CORE IS DISRUPTED BY
INTERACTION AND ULTIMATE ABSORBTION OF INVEST 93S. AFTER THE SYSTEM
REFORMS AND BEGINS TO MOVE WEST, THE UPPER-LEVEL ENVIRONMENT IS
EXPECTED TO IMPROVE, WITH DECREASED VWS AND MORE ROBUST OUTFLOW,
ALLOWING FOR STEADY INTENSIFICATION THROUGH TAU 120. INTENSITY
GUIDANCE IS EXTREMELY UNCERTAIN, WITH A RANGE BETWEEN 40 KNOTS TO 95
KNOTS BETWEEN MODEL OUTLIERS. THE JTWC INTENSITY FORECAST REMAINS
CONSISTENT WITH PREVIOUS FORECASTS, WHICH IS BELOW THE INTENSITY
CONSENSUS THROUGH TAU 48, BUT ABOVE IT AFTER TAU 96. IN LIGHT OF THE
EXTREME UNCERTAINTY, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY
FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030600Z IS 18 FEET. NEXT
WARNINGS AT 031500Z, 032100Z, 040300Z AND 040900Z.//
NNNN

AFTER 36H INVEST 93S  WILL BEGIN TO FUJIWHARA WITH TC 08S AND TRACK NORTHWARDS AROUND THE  WESTERN PERIPHERY OF TC 08S WHICH, WHEN COMBINED BY A WEAKENING OF  THE STEERING ENVIRONMENT, WILL RESULT IN A DRASTIC REDUCTION IN  FORWARD SPEED OF TC 08S. INVEST 93S IS EXPECTED TO BE FULLY ABSORBED  BY TC 08S BY 48H.
AFTER 36H INVEST 93S WILL BEGIN TO FUJIWHARA WITH TC 08S AND TRACK NORTHWARDS AROUND THE WESTERN PERIPHERY OF TC 08S WHICH, WHEN COMBINED BY A WEAKENING OF THE STEERING ENVIRONMENT, WILL RESULT IN A DRASTIC REDUCTION IN FORWARD SPEED OF TC 08S. INVEST 93S IS EXPECTED TO BE FULLY ABSORBED BY TC 08S BY 48H.

INTENSITY  GUIDANCE IS EXTREMELY UNCERTAIN, WITH A RANGE BETWEEN 40 KNOTS TO 95  KNOTS BETWEEN MODEL OUTLIERS. THE JTWC INTENSITY FORECAST REMAINS  CONSISTENT WITH PREVIOUS FORECASTS, WHICH IS BELOW THE INTENSITY  CONSENSUS THROUGH 48H, BUT ABOVE IT AFTER 96H. IN LIGHT OF THE  EXTREME UNCERTAINTY, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY  FORECAST.
INTENSITY GUIDANCE IS EXTREMELY UNCERTAIN, WITH A RANGE BETWEEN 40 KNOTS TO 95 KNOTS BETWEEN MODEL OUTLIERS. THE JTWC INTENSITY FORECAST REMAINS CONSISTENT WITH PREVIOUS FORECASTS, WHICH IS BELOW THE INTENSITY CONSENSUS THROUGH 48H, BUT ABOVE IT AFTER 96H. IN LIGHT OF THE EXTREME UNCERTAINTY, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY FORECAST.

03/0547UTC. ASCAT-B PASS SHOWED A SMALL  AREA OF 50-55 KNOT WINDS TO THE NORTHEAST OF THE LOW LEVEL CIRCULATION CENTER.
03/0547UTC. ASCAT-B PASS SHOWED A SMALL AREA OF 50-55 KNOT WINDS TO THE NORTHEAST OF THE LOW LEVEL CIRCULATION CENTER.
Rédigé par PATRICK HOAREAU le Dimanche 3 Janvier 2021 à 13:25