WPAC: HAISHEN - Post-Tropical

[mrbagyo]

948.3 hPa in Minami

[NotoSans]

Estimates using Schloemer equation and KZC - more uncertain than usual due to concentric eyewalls.
 https://twitter.com/homosapieninhk/status/1302256145843630080

[doomhaMwx]

943.6 mb as of 12am JST!

[mrbagyo]

[1900hurricane]

https://i.imgur.com/k23UC4S.png

Way cool that you can see the moat in both the wind and pressure obs.

[doomhaMwx]

SLP slightly went down further to 942.3 mb at 12:10am JST before rising.

[NotoSans]

Using the lowest pressure of 942.3mb and JMA’s radar tool, Schloemer equation yields a central pressure of 916.7mb.

[NotoSans]

MSLP of 941.8mb was recorded at 0015JST, second lowest on record at Minamidaito (behind Nabi’s 936.8mb).

Maximum 10min sustained winds of 35.0m/s were recorded at 0042JST, 10th highest on record.

Maximum gusts of 50.1m/s were recorded at 0025JST.

[1900hurricane]

Looks like it's trying to hand off to the outer eyewall.

[Highteeld]

Outer eyewall starting to dominate

[aspen]

If this EWRC succeeds, Haishen is going to have a HUGE eye tomorrow.

[sikkar]

952mb @ Kikai island.
https://magicseaweed.com/Japan-Live-Win ... onId=68057

[NotoSans]

Big difference between SMAP and SAR winds. Former yields 115KT while later shows only 90KT.

It looks like SAR winds have systematically underestimated the storm though, so I’d favour SMAP data. Initial intensity estimate for 00Z is 110KT.

[mrbagyo]

[NotoSans]

Kikai airport reported an MSLP of 946.0mb. A blend of Schloemer, SMAP and KZC estimates yields an initial intensity of 110kt/930mb at 00Z.
 https://twitter.com/homosapieninhk/status/1302453611897655296

[1900hurricane]

JTWC's 00Z wind radii are quite large.

WP, 11, 2020090600, , BEST, 0, 275N, 1303E, 95, 944, TY, 34, NEQ, 285, 275, 240, 230, 1002, 260, 17, 0, 25, W, 0, , 0, 0, HAISHEN, D,
WP, 11, 2020090600, , BEST, 0, 275N, 1303E, 95, 944, TY, 50, NEQ, 165, 160, 130, 120, 1002, 260, 17, 0, 25, W, 0, , 0, 0, HAISHEN, D,
WP, 11, 2020090600, , BEST, 0, 275N, 1303E, 95, 944, TY, 64, NEQ, 90, 85, 75, 65, 1002, 260, 17, 0, 25, W, 0, , 0, 0, HAISHEN, D,

[mrbagyo]

[NotoSans]

 https://twitter.com/homosapieninhk/status/1302521748336721920

[euro6208]

WDPN32 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 11W (HAISHEN)
WARNING NR 024//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 11W (HAISHEN), LOCATED APPROXIMATELY 229 NM
SOUTH OF SASEBO, JAPAN, HAS TRACKED NORTHWARD AT 18 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) REVEALS THAT THE SYSTEM CONVECTION AND
EYE STRUCTURE HAVE REMAINED SYMMETRICAL OVER THE PAST
SIX HOURS, WHILE CLOUD TOPS HAVE COOLED SLIGHTLY. THE
NORTHWEST QUADRANT CONTINUES TO EXPERIENCE A FAIR AMOUNT
OF SHEAR, HOWEVER. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE PRESENCE OF THE 28 NM
DIAMETER EYE PRESENT IN THE MSI LOOP, THE COMPOSITE
RADAR LOOP, AND IN A 050407Z ATMS 165 GHZ MICROWAVE
IMAGE. THE INITIAL INTENSITY OF 95 KTS IS PLACED WITH
HIGH CONFIDENCE BETWEEN MULTIAGENCY DVORAK CURRENT
INTENSITY ESTIMATES OF T5.0 (90 KTS, PGTW) AND T5.5
(102 KTS, RJTD) AND NEAR A CIMSS ADVANCED DVORAK
TECHNIQUE CURRENT INTENSITY ESTIMATE OF T5.4 (100 KTS).
ENVIRONMENTAL ANALYSIS INDICATES THE SYSTEM CONTINUES
TO EXPERIENCE STRONG DUAL CHANNEL OUTFLOW AND IS TRACKING
OVER CONTINUED WARM (28-29 CELSIUS) SEA SURFACE
TEMPERATURES (SST), HOWEVER THESE FAVORABLE CONDITIONS
ARE OFFSET BY MODERATE (15-20 KTS) VERTICAL WIND SHEAR
(VWS) ALONG THE NORTHWESTERN PERIPHERY OF THE SYSTEM.
TY HAISHEN IS TRACKING ALONG THE PERIPHERY OF THE
SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST
WHICH HAS CONTINUED TO BUILD EAST-SOUTHEAST OF HOKKAIDO,
JAPAN.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST
PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE.
B. TY HAISHEN WILL CONTINUE TO TRACK POLEWARD THROUGH
THE REMAINDER OF THE FORECAST PERIOD. BY TAU 12, THE
SYSTEM CENTER WILL BEGIN TO PASS WEST OF SASEBO, JAPAN.
AT THIS TIME TY HAISHEN WILL WEAKEN TO 85 KTS DUE TO THE
HIGH VWS TO THE NORTHWEST, AS WELL AS PROGRESSIVELY
COOLER (DROPPING TO 27 CELSIUS) SEA SURFACE TEMPERATURES.
AFTER PASSING WEST OF KYUSHU, THE SYSTEM WILL CONTINUE
TO WEAKEN AND MAKE LANDFALL WEST OF BUSAN, SOUTH KOREA.
INTERACTION WITH THE UNDERLYING TERRAIN, COUPLED WITH
INCREASING VWS, WILL LEAD TO FURTHER WEAKENING TO 60 KTS
BY TAU 24. AFTER TAU 24, THE SYSTEM WILL CONTINUE TO TRACK
POLEWARD AND BRIEFLY OVER THE SEA OF JAPAN BEFORE MAKING
LANDFALL FOR A SECOND TIME AGAIN OVER THE KOREAN PENINSULA.
FURTHER TERRAIN INTERACTION AND HIGH (30+ KTS) VWS WILL
LEAD TO FURTHER WEAKENING AS THE SYSTEM BEGINS
EXTRATROPICAL TRANSITION BY TAU 36. THEREAFTER IT WILL
BECOME FURTHER EMBEDDED IN THE BAROCLINIC ZONE AND COMPLETE
ETT BY TAU 48. NUMERICAL MODELS SOLUTIONS REMAIN IN TIGHT
AGREEMENT WITH THE EXCEPTION OF AFUM WHICH CONTINUES TO BE
AN EXTREME RIGHT-OF-TRACK OUTLIER. AS SUCH, THE JTWC
FORECAST TRACK IS SET WEST OF THE MULTIMODEL CONSENSUS TO
OFFSET THIS UNREALISTIC TRACK GUIDANCE. THE TIGHT OVERALL
AGREEMENT IN NUMERICAL MODEL SOLUTIONS LENDS HIGH CONFIDENCE
IN THE JTWC FORECAST TRACK.//
NNNN

[Highteeld]