TC 16S(GABEKILE): weakening and slow-moving and Invest 93P: updates at 17/06UTC



TC 16S: ANIMATION. CLICK IF NECESSARY.

CIRA/US
CIRA/US
TC 16S(GABEKILE)  SOUTH INDIAN
As of 06:00 UTC Feb 17, 2020:
Location: 20.2°S 75.3°E
Maximum Winds: 60 kt ( 110km/h)
Gusts: 75 kt  ( 140km/h)
Minimum Central Pressure: 986 mb

TPXS11 PGTW 170613
A. TROPICAL CYCLONE 16S (GABEKILE)
B. 17/0600Z
C. 20.15S
D. 75.35E
E. FIVE/MET8
F. T3.5/4.0/W1.5/24HRS  STT: W0.5/03HRS
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN SHEARED 33NM FROM LLCC
YIELDS A DT OF 3.5. MET AGREES AND PT YIELDS A 2.5. DBO DT.
I. ADDITIONAL POSITIONS: NONE
RICHAREMARKS:
170300Z POSITION NEAR 20.3S 75.2E.
17FEB20. TROPICAL CYCLONE (TC) 16S (GABEKILE), LOCATED APPROXIMATELY
809 NM SOUTH OF DIEGO GARCIA, HAS TRACKED NORTH-NORTHEASTWARD AT 04
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY SHOWS THE SYSTEM HAS BECOME QUASI-STATIONARY AND
HAS BEGUN TO WEAKEN AS EVIDENCED BY WARMING CLOUD TOPS AND SLIGHT
UNRAVELING OF THE RAIN BANDS. THE INITIAL POSITION IS PLACED WITH
FAIR CONFIDENCE BASED ON THE EIR ANIMATION AND A SERIES OF MICROWAVE
IMAGES WITH LOW LEVEL CIRCULATION FEATURES THAT INDICATE A TIGHT
LOOPING MOTION. THE INITIAL INTENSITY IS BASED ON OBJECTIVE AND
AGENCY DVORAK ESTIMATES THAT INDICATE A WEAKENING TREND. THE SYSTEM
HAS REACHED THE COL BETWEEN THE STEERING NEAR EQUATORIAL RIDGE (NER)
AND A DEVELOPING LOW-LAYERED (700MB DOWN) SUBTROPICAL RIDGE (STR) TO
THE SOUTHWEST. CONCURRENTLY, AN UPPER LEVEL MID-LATITUDE TROUGH JUST
TO THE WEST IS BEGINNING TO DIG INTO THE NER AND CAUSING SUBSIDENCE
ALONG THE WESTERN FLANK OF TC 16S. ALTHOUGH SST VALUES REMAIN WARM
AT 28-29C AND POLEWARD OUTFLOW REMAINS ROBUST, THE SUBSIDENT EFFECT
AND INCREASING VWS ASSOCIATED WITH THE TROUGH IS OVERALL CAUSING
CONVECTIVE DECAY RESULTING IN THE WEAKENING TREND. BY TAU 36, TC 16S
WILL BE REDUCED TO 45KTS AS IT BEGINS TO SLOWLY TRACK SOUTHWESTWARD
OUT OF THE COL, DRIVEN BY THE STR. COOLING SSTS AND INCREASING VWS
WILL ACCELERATE THE WEAKENING, LEADING TO DISSIPATION BY TAU 72.
NUMERICAL MODELS REMAIN WIDELY SPREAD TO OVER 300NM AT TAU 72,
LENDING LOW CONFIDENCE TO THE JTWC TRACK FORECAST. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 170000Z IS 23 FEET. NEXT WARNINGS AT
171500Z AND 180300Z.//
NNNNRDSON


INVEST 93P SOUTH PACIFIC
As of 06:00 UTC Feb 17, 2020:

Location: 16.2°S 169.6°W
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)

Minimum Central Pressure: 998 mb
ABPW10 PGTW 170600
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 93P) PREVIOUSLY LOCATED
NEAR 11.9S 176.8W IS NOW LOCATED NEAR 15.6S 170.7W, APPROXIMATELY
125 NM SOUTHWEST OF PAGO PAGO, AMERICAN SAMOA. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY AND A 170423Z SSMIS 91GHZ IMAGE DEPICT AN
EXTREMELY LARGE ELONGATED AREA OF DISORGANIZED CONVECTION WITHOUT A
CLEAR CIRCULATION CENTER EXTENDING FROM THE NORTHWEST TO THE
SOUTHEAST. THE SYSTEM IS THE RESULT OF A COMPLEX DYNAMICAL
ENVIRONMENT WITH CONVERGING WINDS FROM THE MONSOON TROUGH (EXTENDING
FROM THE CORAL SEA TO SAMOA), THE SOUTH PACIFIC CONVERGENCE ZONE
(SOUTH OF FIJI), AND INTERACTING WITH WESTERLY WIND BURSTS
ASSOCIATED WITH AN ACTIVE MADDEN-JULIAN OSCILLATION TO THE NORTH
NEAR THE EQUATOR. THE MAIN CONVERGENT LINE, WHICH IS PRODUCING A
LARGE SWATH OF STORM-FORCE WINDS, DEEP CONVECTION, AND HEAVY
PRECIPITATION, IS STRETCHED FROM THE SOLOMON ISLANDS AND CURLS DOWN
INTO A FORMATIVE LOW LEVEL CIRCULATION (LLC) JUST SOUTHWEST OF
AMERICAN SAMOA AS SEEN IN A 170549Z ASCAT-A PASS. INVEST 93P EXISTS
IN A MODERATELY FAVORABLE ENVIRONMENT WITH GOOD POLEWARD AND
EQUATORWARD OUTFLOW AND WARM (29-30C) SEA SURFACE TEMPERATURES.
ALTHOUGH THERE IS A BAND OF LOW VERTICAL WIND SHEAR (VWS) TO THE
NORTH, INVEST 93P IS CURRENTLY EXPERIENCING HIGH (50-60KTS) VWS.
GLOBAL MODELS AGREE THE LLC WILL EMERGE AS THE DOMINANT CYCLONE AND
WILL SUSTAIN THE STORM FORCE WINDS, DEEP CONVECTION, AND HEAVY
PRECIPITATION AS THE SYSTEM TRACKS SOUTHEASTWARD. JTWC WILL CONTINUE
TO EVALUATE 93P FOR POSSIBLE TRANSITION TO A TROPICAL SYSTEM.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS HIGH. SEE REF A (WTPS21 PGTW
161700) FOR FURTHER DETAILS.
 

TC 16S: WARNING 5 AT 00UTC WITH 06UTC POSITION INDICATED


TC 16S: TRACK AND INTENSITY GUIDANCE


INVEST 93P: TRACK AND INTENSITY GUIDANCE


TC 16S: 17/0401UTC


17/0530UTC

Rédigé par PATRICK HOAREAU le Lundi 17 Février 2020 à 11:48