TS WIPHA(08W): near the Leizhou Peninsula, Invest 93W upgraded to MEDIUM


Warning 7/JTWC


WARNING 7/JTWC. INTENSITY SET AT 35KNOTS AND UNLIKELY TO INCREASE SIGNIFICANTLY
WARNING 7/JTWC. INTENSITY SET AT 35KNOTS AND UNLIKELY TO INCREASE SIGNIFICANTLY
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WESTERN NORTH PACIFIC

TS WIPHA(08W)
As of 06:00 UTC Aug 01, 2019:

Location: 20.7°N 111.0°E
Maximum Winds: 35 kt ( 65km/h)
Gusts: 45 kt ( 85km/h)
Minimum Central Pressure: 994 mb

WDPN31 PGTW 010900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (WIPHA)
WARNING NR 07//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 08W (WIPHA), LOCATED APPROXIMATELY 287 NM
EAST OF HANOI, VIETNAM, HAS TRACKED NORTH-NORTHWESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS A COMPACT, WELL-DEFINED LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH FRAGMENTED DEEP CONVECTIVE BANDING. A 010530Z AMSR2
89GHZ IMAGE DEPICTS SHALLOW BANDING WRAPPING INTO A WELL-DEFINED
LLCC, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. A
010245Z ASCAT IMAGE REVEALS A DEFINED CENTER WITH 30 TO 35 KNOT
WINDS OVER THE SOUTH AND EAST QUADRANTS, WHICH SUPPORTS THE INITIAL
INTENSITY ASSESSMENT OF 35 KNOTS. THE ASCAT AMBIGUITY ANALYSIS,
AMSR2 IMAGE, MSI AND A 010716Z GPM 89GHZ IMAGE ALL PROVIDE EVIDENCE
OF AN ABRUPT NORTH-NORTHWESTWARD TURN OVER THE PAST 5-6 HOURS, WHICH
HAS ALLOWED THE SYSTEM TO REMAIN OVER FAVORABLE SST (28-29C) WITH AN
IMPROVED CONVECTIVE SIGNATURE. HOWEVER, THE SYSTEM IS STILL EXPECTED
TO TURN GRADUALLY WESTWARD OVER THE NEXT 12 TO 24 HOURS. UPPER-LEVEL
ANALYSIS INDICATES A MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW TO
MODERATE VERTICAL WIND SHEAR OFFSET BY GOOD POLEWARD AND EQUATORWARD
OUTFLOW. TS 08W IS POSITIONED WEST AND SOUTH OF A LOW- TO MID-LEVEL
SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 08W HAS TRACKED NORTH-NORTHWESTWARD IN THE SHORT-TERM DUE
TO AN EXTENSION OF THE STR TO THE EAST, HOWEVER, THE SYSTEM WILL
GRADUALLY TURN WESTWARD AS IT TRACKS UNDER THE DOMINANT STEERING
INFLUENCE OF THE STR ENTRENCHED TO THE NORTH. THERE IS SOME
UNCERTAINTY IN THE TIMING OF THIS INEVITABLE WESTWARD TURN, WHICH
INTRODUCES SOME UNCERTAINTY IN THE INTENSITY FORECAST AND EXACT
TRACK OVER THE GULF OF TONKIN. THE CURRENT JTWC FORECAST TRACK
SKIRTS THE SOUTHERN COAST OF CHINA WITH LANDFALL ALONG THE NORTHEAST
COAST OF VIETNAM NEAR TAU 42 AND DISSIPATION BY TAU 48 NEAR HANOI.
DYNAMIC MODEL GUIDANCE REFLECTS THIS UNCERTAINTY WITH SOME SOLUTIONS
FURTHER NORTH OVER THE COAST, WHICH COULD LEAD TO GREATER WEAKENING.
DUE TO THIS UNCERTAINTY, THERE IS MODERATE CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN
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INVEST 93W
As of 06:00 UTC Aug 01, 2019:
Location: 19.5°N 152.5°E
Maximum Winds: 20 kt
Minimum Central Pressure: 1003 mb
ABPW10 PGTW 010600
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED
NEAR 21.5N 152.1E, IS NOW LOCATED NEAR 19.3N 153.2E, APPROXIMATELY
607 NM NORTHEAST OF ANDERSEN AFB, GUAM. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND A 010420Z SSMI 37GHZ IMAGE SHOW CONVECTIVE
BANDING OVER THE SOUTHERN SEMICIRCLE WRAPPING INTO A BROAD, WEAK
LLC. RECENT ASCAT INDICATES A BROAD CIRCULATION WITH 15 KNOT WINDS
AND ISOLATED 25-30 KNOT WINDS OVER THE EASTERN QUADRANT. UPPER LEVEL
ANALYSIS SHOWS STRONG EQUATORWARD DIFFLUENCE AND ENHANCED POLEWARD
OUTFLOW WITH A FAVORABLE SHEAR ENVIRONMENT. SEA SURFACE TEMPERATURES
REMAIN WARM (28-30C) IN THE VICINITY OF 93W. GLOBAL MODELS SHOW
STEADY DEVELOPMENT AS THE SYSTEM CONTINUES ON A NORTHWESTWARD TRACK.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
-------------------------------------------------------------------------------------------------------------------------
INVEST 94W
As of 06:00 UTC Aug 01, 2019:
Location: 16.0°N 133.9°E
Maximum Winds: 15 kt
Minimum Central Pressure: 1002 mb
ABPW10 PGTW 010600
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
B. TROPICAL DISTURBANCE SUMMARY:
(2) THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 15.0N 134.8E, IS NOW LOCATED NEAR 15.7N 134.9E, APPROXIMATELY
745 NM SOUTHEAST OF KADENA AB, OKINAWA, JAPAN. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY AND A 010103Z AMSU 89GHZ MICROWAVE IMAGE
DEPICT AN EXPOSED, DISORGANIZED LLC WITH DISPLACED, WEAK CONVECTION
ON THE SOUTHWEST PERIPHERY. UPPER LEVEL ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH MODERATE TO STRONG VWS (20-30 KNOTS) AND
WEAK OUTFLOW. SSTS ARE FAVORABLE FOR DEVELOPMENT AT 27-28C. GLOBAL
MODELS ARE IN GOOD AGREEMENT SHOWING 94W TRACKING NORTHWARD WITH
SLOW DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.
      (3) NO OTHER SUSPECT AREAS.

INVEST 93W UPGRADED TO MEDIUM
INVEST 93W UPGRADED TO MEDIUM

WIPHA(08W): 01/06UTC
WIPHA(08W): 01/06UTC


08W: TRACK AND INTENSITY GUIDANCE
08W: TRACK AND INTENSITY GUIDANCE

93W: TRACK AND INTENSITY GUIDANCE
93W: TRACK AND INTENSITY GUIDANCE

94W: TRACK AND INTENSITY GUIDANCE
94W: TRACK AND INTENSITY GUIDANCE
Rédigé par PATRICK HOAREAU le Jeudi 1 Août 2019 à 13:24