Invest 97W upgraded to Medium. TS Neoguri(21W) update



21W: WARNING 8
21W: WARNING 8
Météo974

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WESTERN NORTH PACIFIC

TS  NEOGURI(21W)
As of 06:00 UTC Oct 18, 2019:

Location: 20.0°N 129.5°E
Maximum Winds: 45 kt ( 85km/h)
Gusts: 55 kt ( 100km/h)

Minimum Central Pressure: 998 mb
WDPN31 PGTW 180900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (NEOGURI) WARNING
NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 21W (NEOGURI), LOCATED APPROXIMATELY 401 NM
SOUTH-SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 03 KNOTS
(KTS) OVER THE PAST SIX HOURS. THERE IS FAIR CONFIDENCE IN THE
INITIAL POSITION BASED ON ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY, REVEALING A SMALL SYSTEM WITH DEEP CONVECTION PRIMARILY
NEAR THE CENTER AND IN THE NORTHEAST QUADRANT. THE LOW LEVEL
CIRCULATION CENTER WAS DETERMINED BY FOLLOWING SHALLOW BANDING TO
THE WEST AND SOUTH UNDER THE CIRRUS SHIELD. THE INITIAL INTENSITY OF
45 KTS IS CONSISTENT WITH THE PGTW DVORAK CURRENT INTENSITY ESTIMATE
OF T3.0 (45 KTS) AND A 180050Z METOP-B ASCAT PASS SHOWING A VERY
SMALL WIND FIELD AND AN AREA OF 45 KT WINDS TO THE NORTH. WITH LOW
(10-15 KT) VERTICAL WIND SHEAR, GOOD POLEWARD OUTFLOW, FAIR
EQUATORWARD OUTFLOW, AND WARM (27-28 CELSIUS) SEA SURFACE
TEMPERATURE, THE ENVIRONMENT APPEARS FAVORABLE. HOWEVER, UPPER LEVEL
CONVERGENCE TO THE WEST IS CAUSING SUBSIDENCE AND DRY AIR
ENTRAINMENT THAT IS LIKELY PARTIALLY OFFSETTING THE OTHERWISE
FAVORABLE ENVIRONMENT TO LIMIT INTENSIFICATION. TS 21W IS TRACKING
SLOWLY ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. THROUGH TAU 36, TS 21W WILL CONTINUE TO TRACK ALONG THE
SOUTHWESTERN PERIPHERY OF THE STR. AFTER TAU 36, THE SYSTEM WILL
BEGIN GRADUALLY TURNING POLEWARD AS IT ROUNDS THE STR AXIS. THE
MARGINALLY FAVORABLE ENVIRONMENT SHOULD ALLOW SOME INTENSIFICATION
THROUGH TAU 36. AFTER TAU 36, HIGH VWS SHOULD PREVENT FURTHER
INTENSIFICATION DESPITE A BRIEF PERIOD WITH ENHANCED POLEWARD
OUTFLOW AS THE SYSTEM BEGINS ROUNDING THE STR AXIS. THERE IS LOW
CONFIDENCE IN THE NEAR TERM INTENSITY FORECAST DUE TO THE COMPETING
INFLUENCES OF VWS AND OUTFLOW NEAR TAU 48. DESPITE THE BULK OF THE
GUIDANCE NOW DEPICTING A RECURVE SCENARIO, THE TRACK FORECAST IS
HIGHLY UNCERTAIN AS THE ECMWF AND ECMWF ENSEMBLE STILL SUGGEST A
WESTWARD TRACK OR EVEN A TURN SOUTHWESTWARD IS POSSIBLE. THROUGH TAU
72, THE JTWC TRACK FORECAST CLOSELY FOLLOWS THE CONSENSUS WITH LOW
CONFIDENCE DUE TO HIGH MODEL UNCERTAINTY.
   C. BEYOND TAU 72, TS 21W IS EXPECTED TO TRACK NORTHEASTWARD AND,
BY TAU 120, BEGIN EXTRATROPICAL TRANSITION AS IT ENCOUNTERS THE MID-
LATITUDE BAROCLINIC ZONE. THE INTENSITY FORECAST HAS VERY LARGE
SPREAD WITH MEMBERS TRACKING ANYWHERE FROM A RECURVE SITUATION
(UKMET ENSEMBLE MEAN, JGSM, GALWEM, UKMET) TO A WESTWARD TRACK
(ECMWF, ECMWF ENSEMBLE MEAN). ADDITIONALLY, THE MEMBERS DEPICTING A
RECURVE HAVE SIGNIFICANTLY DIFFERENT ALONG TRACK SPEEDS. THE ACTUAL
TRACK WILL DICTATE THE INTENSITY BUT WITH THE CURRENT FORECAST
TRACK, HIGH VWS WILL WEAKEN THE SYSTEM CONSIDERABLY. BY TAU 120,
SPREAD EXCEEDS 1400 NM BETWEEN THE MOST EXTREME MEMBERS AND
CONFIDENCE IN THE TRACK FORECAST IS VERY LOW.//
NNNN
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INVEST 97W
As of 06:00 UTC Oct 18, 2019:
Location: 8.7°N 162.2°E
Maximum Winds: 20 kt
Minimum Central Pressure: 1007 mb
ABPW10 PGTW 180600
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 7.6N 171.9E, IS NOW LOCATED NEAR 8.0N 163.8E, APPROXIMATELY 710
NM EAST OF CHUUK. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND AN
180221Z 89GHZ AMSR2 MICROWAVE IMAGE DEPICT A WEAK LOW LEVEL
CIRCULATION BELOW SPARSE, FLARING CONVECTION. THE ENVIRONMENT IS
OVERALL FAVORABLE FOR FURTHER DEVELOPMENT, WITH LOW (5-10KT) VWS,
BROAD WESTWARD OUTFLOW ALOFT, AND VERY WARM (29-31C) SSTS. GLOBAL
MODELS AGREE ON A WEST-NORTHWESTWARD TRACK IN THE NEAR TERM, BUT
VARY ON DEVELOPMENT. GFS AND NAVGEM DEVELOP THE SYSTEM, INTO A
TROPICAL DEPRESSION, WHILE THE ECMWF, UKMO, AND JGSM SHOW AN 850MB
VORTICITY SIGNATURE WITH LITTLE DEVELOPMENT AT THE SURFACE. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.

INVEST 97W: UPGRADED TO MEDIUM
INVEST 97W: UPGRADED TO MEDIUM

21W: 18/06UTC
21W: 18/06UTC

18/1145UTC
18/1145UTC

21W: TRACK AND INTENSITY GUIDANCE
21W: TRACK AND INTENSITY GUIDANCE

INVEST 97W: TRACK AND INTENSITY GUIDANCE
INVEST 97W: TRACK AND INTENSITY GUIDANCE

18/00UTC
18/00UTC

18/00UTC
18/00UTC
Rédigé par PATRICK HOAREAU le Vendredi 18 Octobre 2019 à 15:42