Lekima dissipating north of Shanghai. Krosa south of Japan in 3 days as a typhoon

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WESTERN NORTH PACIFIC

TS LEKIMA(10W)
As of 06:00 UTC Aug 11, 2019:
Location: 34.8°N 119.8°E
Maximum Winds: 35 kt ( 65km/h)
Gusts: 45 kt ( 85km/h)
Minimum Central Pressure: 982 mb
WEAKENING
WDPN31 PGTW 110900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (LEKIMA) WARNING NR
30//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 10W (LEKIMA), LOCATED APPROXIMATELY 232 NM
NORTH-NORTHWEST OF SHANGHAI, CHINA, HAS TRACKED NORTH-NORTHWESTWARD
AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) SHOWS A BROAD, RAGGED AND PARTLY EXPOSED LOW-LEVEL
CIRCULATION (LLC) WITH ERODED CONVECTION SHEARED TO THE NORTH. THE
INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE MSI
ANIMATION AND A COMPOSITE RADAR LOOP FROM CMA. THE INITIAL INTENSITY
OF 35KTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK ESTIMATES AND
NEARBY SURFACE OBSERVATIONS AND REFLECTS THE WEAKENED STATE.
UPPER-LEVEL ANALYSIS INDICATES TS 10W HAS DRIFTED JUST OFFSHORE INTO
THE YELLOW SEA AND INTO AN AREA OF RAPIDLY INCREASING (GREATER THAN
25 KNOTS) SOUTHERLY VERTICAL WIND SHEAR. THERE IS, HOWEVER, STRONG
POLEWARD OUTFLOW THAT IS PROVIDING VENTILATION TO THE DISPLACED
CONVECTION. THE CYCLONE HAS BEEN STRADDLING THE EASTERN CHINA COAST
ALONG THE WESTERN PERIPHERY OF A NORTH-SOUTH ORIENTED SUBTROPICAL
RIDGE (STR) TO THE EAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS LEKIMA IS FORECAST TO CONTINUE ON ITS CURRENT TRACK, STEERED
BY THE STR, AND MAKE ONE FINAL LANDFALL OVER THE SHANDONG PENINSULA
JUST WEST OF QINGDAO. INCREASING VWS AND LAND INTERACTION WILL CAUSE
RAPID DETERIORATION LEADING TO DISSIPATION OVER LAND BY TAU 24.
NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, THEREFORE,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
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TS KROSA(11W)
As of 06:00 UTC Aug 11, 2019:
Location: 23.5°N 139.6°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt (130km/h)
Minimum Central Pressure: 976 mb
WEAKENING
WDPN33 PGTW 110900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KROSA) WARNING NR
023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 11W (KROSA), LOCATED APPROXIMATELY 121 NM
SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED NORTHWESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS VERY BROAD BANDS OF WEAK AND FRAGMENTED CONVECTION SPIRALING
AROUND A LARGE, RAGGED AND PARTLY EXPOSED LOW-LEVEL CIRCULATION (LLC)
WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL
INTENSITY OF 50KTS IS AVERAGED FROM AGENCY DVORAK ESTIMATES RANGING
FROM T3.0/45KTS TO T4.0/65 KTS AND REFLECTS THE OVERALL WEAKENED
STATE. UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH A
LOW DIRECTLY OVER THE LLC THAT IS CAUSING SUBSIDENCE. HOWEVER, AROUND
THE LOW IS A BROAD ANTICYCLONIC OUTFLOW THAT IS PROVIDING VENTILATION
TO THE CONVECTIVE BANDS. ALONG-TRACK SST AT 30C REMAINS CONDUCIVE.
THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A BUILDING
SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. OVER THE NEXT 72 HOURS, TS 11W WILL CONTINUE ON ITS CURRENT
TRACK UNDER THE STR. THE MARGINAL CONDITIONS WILL SUSTAIN THE CURRENT
INTENSITY AT BEST UP TO TAU 36. AFTERWARD, INCREASING POLEWARD
OUTFLOW AHEAD OF A MID-LATITUDE TROUGH WILL PROMOTE INTENSIFICATION
TO A PEAK OF 70 KNOTS BY TAU 72. NUMERICAL MODELS ARE IN GOOD
AGREEMENT, LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC TRACK
FORECAST.
   C. AFTER TAU 72, TS KROSA WILL CREST THE STR AXIS AND TURN
POLEWARD THEN ACCELERATE NORTHEASTWARD, MAKING LANDFALL OVER WESTERN
SHIKOKU JUST BEFORE TAU 96, THEN CROSS INTO THE SEA OF JAPAN (SOJ).
LAND INTERACTION, INCREASING VWS, AND COOLER SSTS IN THE SOJ WILL
COMBINE TO GRADUALLY WEAKEN THE SYSTEM DOWN TO 45 KNOTS AS IT
APPROACHES THE BAROCLINIC ZONE. NUMERICAL MODELS SPREAD OUT TO OVER
260 NM BY TAU 120 WITH NAVGEM AS THE SOLE RIGHT OUTLIER. THERE IS
OVERALL MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK THAT IS LAID
JUST TO THE LEFT OF CONSENSUS TO OFFSET THE UNLIKELY NAVGEM SOLUTION
THAT DRIVES THE VORTEX INTO THE STR.//
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