TC 20S(FERDINAND): CAT 1 US weakening rapidly. 19P(ESTHER): Tropical Cyclone Formation Alert



TC 20S AND OVERLAND TC 19P. ANIMATION. 0930UTC.

TC 20S(FERDINAND) SOUTH INDIAN
As of 06:00 UTC Feb 27, 2020:
Location: 16.6°S 114.3°E
Maximum Winds: 65 kt ( 120km/h)
Gusts: 80 kt ( 150km/h)

Minimum Central Pressure: 984 mb
CATEGORY US: 1

TPXS10 PGTW 270916
A. TROPICAL CYCLONE 20S (FERDINAND)
B. 27/0850Z
C. 16.75S
D. 114.18E
E. FIVE/HMWRI8
F. T3.0/3.5/W2.5/24HRS  STT: S0.0/03HRS
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN WRAPS .65 ON LOG10 SPIRAL
YIELDING A DT OF 3.0. MET IS 3.5. PT IS 3.0. DBO DT.
I. ADDITIONAL POSITIONS: NONE
 MARTIN
REMARKS:
270900Z POSITION NEAR 16.6S 114.1E.
27FEB20. TROPICAL CYCLONE (TC) 20S (FERDINAND), LOCATED APPROXIMATELY
342 NM NORTH OF LEARMONTH, AUSTRALIA, HAS TRACKED WEST-SOUTHWESTWARD
AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL
CIRCULATION CENTER WITH DECAYING DEEP CONVECTION OBSCURING THE
CENTER, THEREFORE, THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION.
MSI ALSO SHOWS EXTENSIVE STRATOCUMULUS (DRIER, MORE STABLE AIR)
ADVECTING OVER THE WESTERN SEMICIRCLE OF THE SYSTEM, WHICH APPEARS
TO BE ENTRAINING INTO THE CORE. UPPER-LEVEL ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH NORTHEASTERLY VERTICAL WIND SHEAR (VWS)
OFFSET BY ROBUST POLEWARD OUTFLOW. THE INITIAL INTENSITY IS ASSESSED
AT 65 KNOTS BASED ON PGTW/KNES DVORAK CURRENT INTENSITY ESTIMATES OF
4.0 (65 KNOTS) AND A 270208Z SATCON ESTIMATE OF 63 KNOTS. TC 20S IS
FORECAST TO TRACK SLOWLY WEST-SOUTHWESTWARD TO WESTWARD THROUGH TAU
36 UNDER THE STEERING INFLUENCE OF THE LOW- TO MID-LEVEL SUBTROPICAL
RIDGE (STR) POSITIONED TO THE SOUTHEAST. THE SYSTEM IS FORECAST TO
WEAKEN SIGNIFICANTLY DUE TO DRY AIR ENTRAINMENT AND PERSISTENT VWS.
AFTER TAU 36, THE SYSTEM WILL CONTINUE TO WEAKEN AND SHOULD STEER
NORTHWESTWARD WITHIN LOW-LEVEL SOUTHEASTERLY FLOW. TC 20S IS
FORECAST TO DISSIPATE BY TAU 72 BUT COULD DISSIPATE EARLIER WITHIN
THE MARGINAL ENVIRONMENT. GLOBAL MODEL GUIDANCE REMAINS IN FAIR
AGREEMENT, THEREFORE, THERE IS MODERATE CONFIDENCE IN THE JTWC
FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270600Z IS 18
FEET. NEXT WARNINGS AT 271500Z, 272100Z, 280300Z AND 280900Z.//
NNNN

OVERLAND TC 19P(ESTHER) SOUTH INDIAN
As of 06:00 UTC Feb 27, 2020:

Location: 15.3°S 129.9°E
Maximum Winds: 35 kt
Minimum Central Pressure: 999 mb
TPXS11 PGTW 270910
A. REMNANTS OF TROPICAL CYCLONE 19P (ESTHER)
B. 27/0850Z
C. 15.17S
D. 129.97E
E. FIVE/HMWRI8
F. N/A
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. DVORAK VALUES UNAVAILABLE DUE TO
LLCC OVER LAND.
I. ADDITIONAL POSITIONS: NONE
MARTIN
WTXS21 PGTW 270300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (REMNANTS OF TC 19P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 15.5S 131.0E TO 14.9S 127.4E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 30 TO 35 KNOTS. METSAT
IMAGERY AT 270000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.5S 130.8E. THE SYSTEM IS MOVING WESTWARD AT 06 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION (REMNANTS OF TC 19P) PREVIOUSLY LOCATED NEAR
15.4S 132.0E IS NOW LOCATED NEAR 15.5S 130.8E, APPROXIMATELY 185NM
SOUTH OF DARWIN, AUSTRALIA.  MULTISPECTRAL SATELLITE IMAGERY AND A
262028Z SSMIS 91GHZ MICROWAVE IMAGE SHOW CONVECTIVE BANDING FROM THE
NORTH WRAPPING INTO A LOW LEVEL CIRCULATION (LLC). THE REMNANTS OF
TC 19P ARE EXPERIENCING FAVORABLE UPPER LEVEL CONDITIONS FOR
DEVELOPMENT WITH NEAR RADIAL OUTFLOW AND LOW (10-15KTS) VERTICAL
WIND SHEAR. THE MAJORITY OF GLOBAL MODELS ARE IN AGREEMENT THAT THE
REMNANTS OF TC 19P WILL TRACK WESTWARD ACROSS AUSTRALIA SKIRTING
ALONG THE NORTHWESTERN COAST PRIOR TO TURNING TO A SOUTHWARD TRACK.
PRIOR TO THIS SOUTHWARD TURN, THE REMNANTS OF TC 19P WILL TRACK
ALONG THE SOUTHERN COASTLINE OF THE JOSEPH BONAPARTE GULF. SPREAD IN
THE MODEL SOLUTIONS WILL IMPACT THE AMOUNT OF TIME THE REMNANTS OF
TC 19P WILL SPEND PASSING OVER WATER ALONG THE COAST AND THUS IMPACT
SYSTEM INTENSITY. THEREFORE, WITH HIGH (30-31C) SEA SURFACE
TEMPERATURES AND CONDUCIVE UPPER LEVEL SUPPORT, THE REMNANTS OF TC
19P COULD INTENSIFY AND REACH WARNING CRITERIA WITHIN THEN NEXT 24
HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
280300Z.




 

TC 20S: WARNING 15. WEAKENING . CLICK TO ANIMATE.


 

OVERLAND TC 19P: TCFA


 

TC 20S: TRACK AND INTENSITY GUIDANCE


OVERLAND TC 19P: TRACK AND INTENSITY GUIDANCE


27/0545UTC


TC 20S.27/0850UTC


TC 19P. 27/0508UTC

Rédigé par PATRICK HOAREAU le Jeudi 27 Février 2020 à 14:45