WPAC: MAYSAK - Post-Tropical

[aspen]

That’s an awful lot of outer banding. I could see this quickly trying to undergo an EWRC not long after getting a completed inner core, if those bands remain.

[Highteeld]

https://rammb-data.cira.colostate.edu/tc_realtime/products/storms/2020wp10/amsusr89/2020wp10_amsusr89_202008291947.gif
That’s an awful lot of outer banding. I could see this quickly trying to undergo an EWRC not long after getting a completed inner core, if those bands remain.

Looks like there could be two at once

[1900hurricane]

[aspen]

https://i.imgur.com/RNQAnrE.jpg

Don’t tell me Maysak is trying to form an eyewall half the size of Texas.

[euro6208]

New peak at 120 knots.

WDPN31 PGTW 292100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (MAYSAK) WARNING NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 10W (MAYSAK), LOCATED APPROXIMATELY 584 NM SOUTH OF
KADENA AB, OKINAWA, HAS TRACKED WEST-NORTHWESTWARD AT 03 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A CONSOLIDATING SYSTEM WITH A CENTRAL DENSE OVERCAST
OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 291640Z AMSR2
36GHZ MICROWAVE IMAGE, HOWEVER, REVEALS TIGHTLY-CURVED BANDING
WRAPPING INTO AN OBLONG MICROWAVE EYE FEATURE, WHICH SUPPORTS THE
INITIAL POSITION AND RECENT TRACK MOTION WITH GOOD CONFIDENCE. UPPER-
LEVEL ANALYSIS INDICATES A VERY FAVORABLE ENVIRONMENT WITH AN
ENHANCED POLEWARD OUTFLOW CHANNEL INTO A BROAD UPPER LOW POSITIONED
TO THE NORTHEAST, GOOD EQUATORWARD OUTFLOW AND LOW VERTICAL WIND
SHEAR (VWS). ADDITIONALLY, SST VALUES (30-31C) AND HIGH OCEAN HEAT
CONTENT VALUES ARE CONDUCIVE FOR FURTHER DEVELOPMENT. THE 29/12Z
500MB ANALYSIS INDICATES AN UPPER LOW NEAR 25N 135E ASSOCIATED WITH
THE AFOREMENTIONED BROAD 200MB LOW; THIS SYNOPTIC ENVIRONMENT HAS
LED TO A WEAK STEERING ENVIRONMENT WITH SLOW / QUASI-STATIONARY
TRACK MOTION OVER THE PAST DAY. CURRENTLY, THE SYSTEM HAS TURNED
ONTO A SLOW WEST-NORTHWESTWARD OR PERHAPS NORTHWESTWARD
TRACK.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. THE UPPER LOW TO THE NORTHEAST IS FORECAST TO TRACK WESTWARD
WHILE WEAKENING OVER THE NEXT 12 HOURS AS IT TRACKS ALONG THE
NORTHERN PERIPHERY OF TY 10W. THIS WILL ALLOW THE STEERING
SUBTROPICAL RIDGE (STR) TO BUILD EAST OF THE SYSTEM SUPPORTING A
STEADY NORTHWARD TO NORTH-NORTHWESTWARD TRACK THROUGH TAU 48. THE
PRESENCE OF AN EXTENSION OF THE STR TO THE NORTH, OVER WESTERN JAPAN
AND THE KOREAN PENINSULA WILL ALSO INFLUENCE THE FORECAST TRACK
PRODUCING A NORTH-NORTHWESTWARD TRACK THROUGH TAU 60 AS THE SYSTEM
SKIRTS TO THE WEST OF OKINAWA. THE STR EXTENSION SHOULD ERODE AFTER
TAU 60 WITH THE APPROACH OF A DEEP MIDLATITUDE SHORTWAVE TROUGH OVER
EASTERN CHINA THEREFORE TY 10W SHOULD TRACK MORE POLEWARD. WITH THE
EXCEPTION OF AFUI, NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT AT
TAU 60 (WEST OF OKINAWA) WITH A 125NM SPREAD IN SOLUTIONS. UNDER
VERY FAVORABLE CONDITIONS, TY 10W IS FORECAST TO RAPIDLY INTENSIFY
OVER THE NEXT 36 HOURS WITH A PEAK INTENSITY OF 120 KNOTS AT TAU 48.
SLIGHT WEAKENING IS ANTICIPATED BY TAU 72 AS SST VALUES COOL
SLIGHTLY TO 28-29C.
C. IN THE EXTENDED PERIOD, TY 10W IS FORECAST TO ACCELERATE NORTH-
NORTHEASTWARD AS IT BEGINS EXTRA-TROPICAL TRANSITION (ETT) AND
BEGINS TO INTERACT WITH THE AFOREMENTIONED MIDLATITUDE SHORTWAVE
TROUGH. SIGNIFICANT WEAKENING WILL OCCUR AFTER TAU 96 AS THE SYSTEM
TRACKS OVER THE MOUNTAINOUS KOREAN PENINSULA AND ENCOUNTERS
INCREASING VWS ASSOCIATED A MIDLATITUDE JET. TY 10W WILL COMPLETE
ETT BY TAU 120 AS IT GAINS FRONTAL CHARACTERISTICS AND TRACKS UNDER
THE JET. NUMERICAL MODELS DIVERGE WITH A 255NM SPREAD IN SOLUTIONS
AT TAU 120. THE JTWC FORECAST TRACK IS POSITIONED JUST EAST OF THE
MULTI-MODEL CONSENSUS, CLOSER TO THE ECMWF / EEMN SOLUTIONS. OVERALL
THERE IS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE
ERRATIC INITIAL MOTION AND UNCERTAINTY IN EXTENDED PERIOD.//
NNNN

[aspen]

RI is going to have to wait, Maysak is too busy trying to form an eyewall large enough to swallow the entire island of Taiwan. Banding has broken up the CDO that formed today, and now I can’t even tell where the center is, or where it’ll form.

[Highteeld]

my speculation about an eye coming out later today seem to be dubious given how huge the eyewall will be

[Highteeld]

This is going to be like Super Typhoon Lan in terms of structure

[aspen]

This is going to be like Super Typhoon Lan in terms of structure

With such a large core forming (it has seemingly shrunk to smaller than Taiwan) and such extensive outflow, Maysak could become an absolutely enormous system like Lan, maybe the largest of the entire year.

First we had Micro Marco, now it’s time for Mega Maysak.

[mrbagyo]

[1900hurricane]

Don't think the eye size is quite going to match Lan, but definitely looks like a larger than average one developing. And yeah, this is going to be a big system. Lots of big wind radii in guidance solutions. RVCN, which is one of the main wind radii aids, has the 34 kt radius up near 200 nm near and following peak. Some of the dynamic runs, like CTCX, are even bigger.

Anyway, here's my 00Z forecast. Philosophy is fairly similar to my first one at 12Z. Guidance points in the short term have been tugged back slightly in response to a little bit slower initial motion, and the near term forecast has been brought back just a little initially due to the core reorganization, but both track and intensity is just about the same. Track takes it between Okinawa and Miyakojima and then into South Korea. Still like the prospects of rapid intensification sooner than later.

 https://twitter.com/1900hurricane/status/1299895767126155266



 https://twitter.com/1900hurricane/status/1299895769844121600

[euro6208]

WDPN31 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (MAYSAK) WARNING NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 10W (MAYSAK), LOCATED APPROXIMATELY 566 NM SOUTH
OF KADENA AB, OKINAWA, HAS TRACKED NORTHWESTWARD AT 03 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS TIGHTLY-CURVED BANDING WRAPPING INTO A CONSOLIDATING LOW-
LEVEL CIRCULATION CENTER (LLCC). A 292150Z GMI 37GHZ COLOR COMPOSITE
IMAGE DEPICTS A THICK CYAN RING, INDICATIVE OF AN IMMINENT RAPID
INTENSIFICATION PHASE, AND A WELL-DEFINED MICROWAVE EYE FEATURE,
WHICH SUPPORTS THE INITIAL POSITION AND RECENT TRACK MOTION WITH
GOOD CONFIDENCE. UPPER-LEVEL ANALYSIS INDICATES A VERY FAVORABLE
ENVIRONMENT WITH AN ENHANCED POLEWARD OUTFLOW CHANNEL INTO A BROAD
UPPER LOW POSITIONED TO THE NORTHEAST, GOOD EQUATORWARD OUTFLOW AND
LOW VERTICAL WIND SHEAR (VWS). ADDITIONALLY, SST VALUES (30-31C) AND
HIGH OCEAN HEAT CONTENT VALUES ARE CONDUCIVE FOR FURTHER
DEVELOPMENT. THE 29/12Z 500MB ANALYSIS INDICATES AN UPPER LOW NEAR
25N 135E ASSOCIATED WITH THE AFOREMENTIONED BROAD 200MB LOW; THIS
SYNOPTIC ENVIRONMENT HAS LED TO A WEAK STEERING ENVIRONMENT WITH
SLOW / QUASI-STATIONARY TRACK MOTION OVER THE PAST DAY. CURRENTLY,
THE SYSTEM HAS TURNED ONTO A SLOW NORTHWESTWARD TRACK.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. THE UPPER LOW TO THE NORTHEAST IS FORECAST TO TRACK WESTWARD
WHILE WEAKENING OVER THE NEXT SIX HOURS AS IT TRACKS ALONG THE
NORTHERN PERIPHERY OF TY 10W. THIS WILL ALLOW THE STEERING
SUBTROPICAL RIDGE (STR) TO BUILD EAST OF THE SYSTEM SUPPORTING A
STEADY NORTHWARD TO NORTH-NORTHWESTWARD TRACK THROUGH TAU 48. THE
PRESENCE OF AN EXTENSION OF THE STR TO THE NORTH, OVER WESTERN JAPAN
AND THE KOREAN PENINSULA WILL ALSO INFLUENCE THE FORECAST TRACK
PRODUCING A NORTH-NORTHWESTWARD TRACK THROUGH TAU 60 AS THE SYSTEM
SKIRTS TO THE WEST OF OKINAWA. THE STR EXTENSION SHOULD ERODE AFTER
TAU 60 WITH THE APPROACH OF A DEEP MIDLATITUDE SHORTWAVE TROUGH OVER
EASTERN CHINA THEREFORE TY 10W SHOULD TRACK MORE POLEWARD. WITH THE
EXCEPTION OF AFUI, NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT AT
TAU 60 (WEST OF OKINAWA) WITH A 90NM SPREAD IN SOLUTIONS. UNDER
VERY FAVORABLE CONDITIONS, TY 10W IS FORECAST TO RAPIDLY INTENSIFY
OVER THE NEXT 36 HOURS WITH A PEAK INTENSITY OF 120 KNOTS AT TAU 36.
SLIGHT WEAKENING IS ANTICIPATED BY TAU 72 AS SST VALUES COOL
SLIGHTLY TO 28-29C.
C. IN THE EXTENDED PERIOD, TY 10W IS FORECAST TO ACCELERATE NORTH-
NORTHEASTWARD AS IT BEGINS EXTRA-TROPICAL TRANSITION (ETT) AND
BEGINS TO INTERACT WITH THE AFOREMENTIONED MIDLATITUDE SHORTWAVE
TROUGH. SIGNIFICANT WEAKENING WILL OCCUR AFTER TAU 90 AS THE SYSTEM
TRACKS OVER THE MOUNTAINOUS KOREAN PENINSULA AND ENCOUNTERS
INCREASING VWS ASSOCIATED A MIDLATITUDE JET. TY 10W WILL COMPLETE
ETT BY TAU 120 AS IT GAINS FRONTAL CHARACTERISTICS AND TRACKS UNDER
THE JET. NUMERICAL MODELS DIVERGE WITH A 185NM SPREAD IN SOLUTIONS
AT TAU 120. THE JTWC FORECAST TRACK IS POSITIONED NEAR THE
MULTI-MODEL CONSENSUS, CLOSER TO THE ECMWF / EEMN SOLUTIONS. OVERALL
THERE IS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE
ERRATIC INITIAL MOTION AND UNCERTAINTY IN EXTENDED PERIOD.//
NNNN

[Highteeld]

Would probably go 75-80 knots with around 970 mb for 6z

[euro6208]

TPPN10 PGTW 300636

A. TYPHOON 10W (MAYSAK)

B. 30/0600Z

C. 18.62N

D. 129.05E

E. THREE/HMWRI8

F. T4.5/4.5/D1.5/24HRS STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 15A/PBO TIGHTLY CURVED BNDG/ANMTN. CNVCTN WRAPS 1.4
ON LOG10 SPIRAL YIELDING A DT OF 4.5. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


YOUNG

[Highteeld]

10W MAYSAK 200830 0600 18.4N 129.1E WPAC 75 971

[Highteeld]

[doomhaMwx]

24hr intensity forecast from yesterday's HWRF run is so off, and it's still likely intensifying Maysak way too fast in today's run.

[mrbagyo]

Wierd moaty structure

[aspen]

8z microwave pass shows a large but just about complete eyewall.

[euro6208]

TPPN11 PGTW 301224

A. TYPHOON 10W (MAYSAK)

B. 30/1200Z

C. 19.40N

D. 129.30E

E. FIVE/HMWRI8

F. T5.0/5.0/D1.5/24HRS STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 46A/PBO EMBD CNTR/ANMTN. LLCC EMBEDDED IN W YIELDS
A DT OF 5.0. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


YOUNG