WPAC: MAYSAK - Post-Tropical

[NotoSans]

Using JMA's radar tools, the center was positioned at 26.070N 126.464E (i.e. 45km from Kumejima) at 18Z. The eye radii was 25km, which yielded an RMW estimate of 37.5km.

Kumejima recorded a SLP of 960.6mb, and POCI was 1004mb based on JMA's surface weather map.

The above inputs result in a central pressure of 927.2mb using the Schloemer equation. However, Maysak seem to exhibit concentric eyewalls, and the equation may have low bias for this type of structure (especially when the weather station is outside the RMW). Still, I'd place the central pressure at 930mb at 18Z.

[NotoSans]

The above central pressure estimate yields an intensity of 125kt at 18Z. However, KZC has a high bias for concentric eyewalls. Also given the weak southern eyewall which may affect surface mixing, I would place the intensity slightly lower at 120kt at 18Z.

 https://twitter.com/homosapieninhk/status/1300500685985730560

[Hayabusa]

940 mb

TY 2009 (Maysak)
Issued at 18:45 UTC, 31 August 2020

<Analysis at 18 UTC, 31 August>
Scale Large
Intensity Very strong
Center position N26°00' (26.0°)
E126°30' (126.5°)
Direction and speed of movement NNW 25 km/h (13 kt)
Central pressure 940 hPa
Maximum wind speed near center 45 m/s (90 kt)
Maximum wind gust speed 65 m/s (130 kt)
≥ 50 kt wind area ALL 185 km (100 NM)
≥ 30 kt wind area E 560 km (300 NM)
W 440 km (240 NM)

10W MAYSAK 200831 1800 26.1N 126.6E WPAC 115 933

[1900hurricane]

Pretty salty obs last hour at Kitahara. Don't think the true RMW quite made it in there, but the 40.6 m/s 10 minute winds is supportive of 90 kt 1 minute sustained, way stronger than at the other end of the island.

[aspen]

First visible. The eye has shrunk considerably, and while it has cooled, eye temps remain positive and convection surrounding it is still quite deep.

[doomhaMwx]

That sudden left turn and how it immediately made it back to the right is fun to watch, as if it was dodging something.

 https://twitter.com/RobertSpetaWX/status/1300563058880897024

[doomhaMwx]

ERC soon. Maysak's intensity is probably going downhill from here on out.

[euro6208]

TPPN11 PGTW 312125

A. TYPHOON 10W (MAYSAK)

B. 31/2100Z

C. 26.49N

D. 126.18E

E. ONE/HMWRI8

F. T6.0/6.0/D1.0/24HRS STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 05A/PBO IRREG EYE/ANMTN. OW EYE SURROUNDED BY B
YIELDS AN E# OF 5.5. ADDED 0.5 EYE ADJUSTMENT FOR W, TO YIELD A
DT OF 6.0. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS:
31/1646Z 25.87N 126.55E ATMS
31/1736Z 25.92N 126.60E MMHS


HEINS

[Hayabusa]

TY 2009 (Maysak)
Issued at 00:50 UTC, 1 September 2020

<Analysis at 00 UTC, 1 September>
Scale Large
Intensity Very strong
Center position N26°55' (26.9°)
E125°55' (125.9°)
Direction and speed of movement NNW 20 km/h (10 kt)
Central pressure 935 hPa
Maximum wind speed near center 50 m/s (95 kt)
Maximum wind gust speed 70 m/s (135 kt)
≥ 50 kt wind area ALL 200 km (110 NM)
≥ 30 kt wind area E 560 km (300 NM)
W 440 km (240 NM)

[euro6208]

TPPN11 PGTW 010301

A. TYPHOON 10W (MAYSAK)

B. 01/0230Z

C. 27.19N

D. 125.97E

E. ONE/HMWRI8

F. T6.5/6.5/D1.0/24HRS STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 07A/PBO IRREG EYE/ANMTN. OW EYE SURROUNDED BY W
YIELDS AN E# OF 6.0. ADDED 0.5 EYE ADJUSTMENT FOR W, TO YIELD A
DT OF 6.5. MET AND PT YIELD 6.0. DBO DT.

I. ADDITIONAL POSITIONS:
31/2210Z 26.80N 126.18E MMHS
31/2239Z 26.80N 126.10E SSMS


HEINS

[euro6208]

I wonder why they didn't factor in dvorak of 6.5 and ADT?

Probably somewhere between 125 to 135 knots.


CI# /Pressure/ Vmax
6.5 / 929.9mb/127.0kt

Laura equivalent.

[1900hurricane]

Think Maysak is peaking right now.

 https://twitter.com/1900hurricane/status/1300625232693211136



 https://twitter.com/1900hurricane/status/1300625235159527425



 https://twitter.com/1900hurricane/status/1300625237021782021

[doomhaMwx]

 https://twitter.com/EarthUncutTV/status/1300639530140065793

[cheezyWXguy]

I wonder why they didn't factor in dvorak of 6.5 and ADT?

Probably somewhere between 125 to 135 knots.


CI# /Pressure/ Vmax
6.5 / 929.9mb/127.0kt

Laura equivalent.

I think it’s possible dvorak could be overstating things a little bit. Concentric eyewalls could be flattening the pressure gradient and that weakness in the sw quad probably isn’t helping.

[1900hurricane]

Actually a pretty nice visible image right now.

[euro6208]

JT really lagging here. Justifies at least 130 knots. This is slightly stronger than Laura based on the graphic. But no recon.

CURRENT ESTIMATE
Date (mmddhhmm): 09010450
SATCON: MSLP = 927 hPa MSW = 128 knots
SATCON Member Consensus: 125.0 knots
Pressure -> Wind Using SATCON MSLP: 117 knots
Distance to Outer Closed Isobar Used is 240 nm
Eye Size Correction Used is 1.1 knots Source: IR

Member Estimates

ADT: 932 hPa 125 knots Scene: CDO Date: SEP010530
CIMSS AMSU: 913 hPa 137 knots Bias Corr: 0 (MW) Date: 09010120
ATMS: 922.9 hPa 123.4 knots Date: 09010450
SSMIS: 922.9 hPa 123.4 knots Date: 09010450

[Hayabusa]

Almost super

10W MAYSAK 200901 0600 27.6N 126.1E WPAC 125 921

[NotoSans]

I'd probably have lowered or maintained the intensity at 06Z instead. AMSU estimate was inaccurate due to erroneous RMW estimate. 06Z EIR frame was clear-cut T6.0 (surrounding convection is LG, not B).

Maysak clearly weakening now, with eye becoming less well-defined.

[euro6208]

[euro6208]

TPPN11 PGTW 010854

A. TYPHOON 10W (MAYSAK)

B. 01/0830Z

C. 28.03N

D. 126.18E

E. ONE/HMWRI8

F. T6.5/6.5/D1.0/24HRS STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 03A/PBO EYE/ANMTN. OW EYE SURROUNDED BY B YIELDS AN
E# OF 5.5. ADDED 0.5 EYE ADJUSTMENT FOR W, TO YIELD A DT OF
6.0. MET AGREES, PT YIELDS 6.5. DBO PT.

I. ADDITIONAL POSITIONS: NONE


RHOADES