Tapah(18W) near peak intensity, forecast to be fully extratropical in 36h

Météo974

M974World

WESTERN NORTH PACIFIC

TS TAPAH(18W)
As of 18:00 UTC Sep 21, 2019:
Location: 29.6°N 126.0°E
Maximum Winds: 60 kt ( 110km/h)
Gusts: 75 kt ( 140km/h)
Minimum Central Pressure: 973 mb
WDPN31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (TAPAH) WARNING NR
012//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 18W (TAPAH), LOCATED APPROXIMATELY 283 NM
SOUTHWEST OF SASEBO, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 12
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS AN EXPANSIVE CLOUD FIELD AND A BROAD EYE-LIKE FEATURE.
THE INITIAL POSITION IS PLACE WITH FAIR CONFIDENCE BASED ON A 211601Z
GMI 37GHZ MICROWAVE IMAGE, WHICH SHOWS THE BROAD NATURE OF THE
SYSTEM. THE INTENSITY OF 60 KNOTS IS HEDGED BETWEEN DVORAK CURRENT
INTENSITY (CI) ESTIMATES OF T4.0 (65 KNOTS) FROM PGTW AND T3.5 (55
KNOTS) FROM KNES. ENVIRONMENTAL ANALYSIS REVEALS THAT TS 18W IS
EXPERIENCING NEUTRAL (15 TO 20 KNOT) VERTICAL WIND SHEAR. TS 18W HAS
A ROBUST POLEWARD OUTFLOW CHANNEL BUT LITTLE TO NO EQUATORWARD
OUTFLOW. SEA SURFACE TEMPERATURES REMAIN FAVORABLE, BETWEEN 27 AND 28
DEGREES CELSIUS. TS 18W IS TRACKING NORTH-NORTHEASTWARD WHILE UNDER
THE INFLUENCE OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. THE AFOREMENTIONED STR WILL REMAIN THE PRIMARY STEERING FEATURE
IN THE SHORT TERM. AS TS 18W TRACKS AROUND THE STR THE TRACK WILL
SHIFT FROM NORTH-NORTHEASTWARD TO NORTHEASTWARD. FAVORABLE SEA
SURFACE TEMPERATURES AND STRONG POLEWARD OUTFLOW OFFSET BY
INCREASING VERTICAL WIND SHEAR WILL ALLOW FOR A GRADUAL DECREASE IN
INTENSITY. AS TS 18W TRACKS AROUND THE STR IT WILL BEGIN TO INTERACT
WITH THE MIDLATITUDE WESTERLIES. INTERACTION WITH THE BAROCLINIC ZONE
WILL CAUSE TS 18W TO BEGIN EXTRATROPICAL TRANSITION (ETT) BY TAU 24
AND COMPLETE ETT BY TAU 36. AFTER ETT, A GALE FORCE WIND FIELD WILL
REMAIN AND RAPIDLY TRACK NORTHEASTWARD. DYNAMIC MODEL GUIDANCE
REMAINS IN GOOD AGREEMENT THROUGH TAU 36 WITH AN INCREASING ALONG-
TRACK SPREAD BY TAU 48. THE JTWC FORECAST TRACK IS PLACED NEAR THE
MULTI-MODEL CONSENSUS. OVERALL, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN
-----------------------------------------------------------------------------------------------------------------
NORTH INDIAN

INVEST 96A
As of 18:00 UTC Sep 21, 2019:
Location: 19.2°N 69.9°E
Maximum Winds: 25 kt
Minimum Central Pressure: 1002 mb
ABIO10 PGTW 211800
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION (INVEST 96A) PREVIOUSLY LOCATED NEAR
19.2N 70.7E, IS NOW LOCATED NEAR 19.2N 70.2E APPROXIMATELY 150 NM
WEST OF MUMBAI, INDIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
AND A 211621Z 89GHZ METOP-B IMAGE DEPICT A SLOWLY CONSOLIDATING LOW
LEVEL CIRCULATION WITH DEEP FLARING CONVECTION TO THE WEST.
UPPER LEVEL ANALYSIS REVEALS 96A IS MOVING INTO AN AREA OF MODERATE
VERTICAL WIND SHEAR (15-25 KNOTS) AND HAS VERY LITTLE OUTFLOW ALOFT.
SEA SURFACE TEMPERATURES REMAIN FAVORABLE AT 27-28 DEGREES CELSIUS.
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 96A WILL SLOWLY TRACK
WESTWARD, BUT ONLY GSM AND NAVGEM SHOW 96A REACHING SUSTAINED WINDS
OF 25 KNOTS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO
20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.