WPAC: GUCHOL - Post-Tropical

[Extratropical94]

Whoa, I've just noticed this (from JTWC's advisory):

MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171200Z IS 54 FEET.

[RobWESTPACWX]

54ft ouch, Im sure those no ships remotely near that though, and if there is well. Ouch is about the right word for it.

[tolakram]

Latest MTSAT Infrared



from: http://163.251.239.142/public/Satellite.aspx?site=1 or http://163.251.239.142/public/Satellite.aspx?site=2

[senorpepr]

WTPQ20 RJTD 171800
RSMC TROPICAL CYCLONE ADVISORY
NAME TY 1204 GUCHOL (1204)
ANALYSIS
PSTN 171800UTC 20.8N 127.0E GOOD
MOVE N 12KT
PRES 950HPA
MXWD 085KT
GUST 120KT
50KT 80NM
30KT 250NM SOUTHEAST 200NM NORTHWEST
FORECAST
24HF 181800UTC 27.3N 129.4E 85NM 70%
MOVE NNE 19KT
PRES 960HPA
MXWD 075KT
GUST 105KT
48HF 191800UTC 36.0N 135.6E 180NM 70%
MOVE NNE 25KT
PRES 980HPA
MXWD 055KT
GUST 080KT
72HF 201800UTC 41.6N 146.3E 250NM 70%
MOVE NE 29KT
PRES 992HPA
MXWD 045KT
GUST 065KT =

[brunota2003]

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The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Looks like the inner eyewall is about to completely give up the ghost as the outer eyewall intensifies (was looking at mimic, but it has updated since 1145 UTC)...likewise, the presentation has fallen apart quite a bit, with almost all of the deep convection on the southern side of the system. The whites and greys (on Dvorak images) no longer surround the eye...there is a nice break in the Northern portion of the storm. I'd take a guess that it has weakened down to 105 or 110 knots now...definitely not the 130 knots it was yesterday.

[cycloneye]

This was at peak intensity. Good to save right?



Uploaded with imageshack.us

[cycloneye]

70 miles east of Okinawa on this 21:00z track by JTWC.

[senorpepr]

Looking at the 20Z MTSAT image... Guchol is not holding up well.

I'm interested to see how JTWC analyzes this one... all day it seems they've been "bullish" on the Dvorak estimates. They've measured thicker bands than I'm seeing from NRL's BD curve.

Anyway, here's my 20Z take: about 21.4N 127.4E. White and black bands are now broken on the NW side. Light grey was about 45 n mi, so I've set E# to 5.0. With the broken bands, the eye adjustment between off-white and light grey yields 0. I don't see a banding feature that meets requirements, so DT is 5.0.

Although I've been lower all day than JTWC (and closer to KNES), my final Dvorak number is T5.0/5.5/W1.0/24 h; STT W0.5/3 h

ADT is a little higher, with a final T of 5.5.

[brunota2003]

What does that translate out to in knots?

[tolakram]

Current IR, you can see the outer eyewall (I think).

[Extratropical94]

MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171800Z IS 60 FEET.

[cycloneye]

21:00Z warning JTWC discussion:

WDPN31 PGTW 172100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 05W (GUCHOL) WARNING NR 28//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 05W (GUCHOL), LOCATED APPROXIMATELY 350 NM SOUTH OF
KADENA AB, OKINAWA, HAS TRACKED NORTHWARD AT 11 KNOTS OVER THE PAST
SIX HOURS. TY 05W HAS RECENTLY BEEN DOWNGRADED FROM SUPER TYPHOON
STATUS TO TYPHOON. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY
SHOWS THE SYSTEM HAS STARTED TO SHOW SIGNS OF WEAKENING AS THE EYE
DIAMETER HAS SLOWLY DECREASED OVER THE PAST SIX HOURS FROM 15 NM TO
10 NM AND IS BECOMING MORE RAGGED. THE DEEPEST CONVECTION REMAINS ON
THE SOUTHERN HALF OF THE SYSTEM, BUT CONVECTION ALONG THE
NORTHWESTERN QUADRANT HAS STARTED TO WEAKEN SLIGHTLY OVER THE PAST
SIX HOURS. THE EYEWALL REPLACEMENT CYCLE (ERC) HAS FINISHED WITH NO
IDENTIFIABLE IMPACT TO THE OVERALL INTENSITY. TY 05W HAS SHIFTED TO A
NORTHWARD TRACK AT THE WARNING TIME, AND SINCE ISSUING WARNING NUMBER
28, EIR IMAGERY IS INDICATING A SLIGHT TURN TO THE EAST-NORTHEAST AS
TY 05W APPEARS TO HAVE STARTED TO TRACK AROUND THE DEEP-LAYERED
SUBTROPICAL RIDGE (STR) AXIS. THE CURRENT POSITION IS BASED ON THE
EYE IN EIR AND AGREES WITH PGTW FIX. THE CURRENT INTENSITY IS
SLIGHTLY DECREASED TO 125 KNOTS BASED ON A 6.0/6.5 DVORAK FIX FROM
PGTW AND A 5.0/5.5 FROM RJTD BOTH SHOWING A SLIGHT WEAKENING TREND.
THIS AGREES WITH THE OBSERVED WEAKENING TREND NOTED IN EIR.
UPPER-LEVEL ANALYSIS INDICATES THE MESOSCALE ANTICYCLONE REMAINS
SLIGHTLY DISPLACED LOW-LEVEL CIRCULATION CENTER (LLCC). THIS FEATURE
CONTINUES TO VENT THE SYSTEM ALONG THE EQUATORWARD OUTFLOW CHANNEL.
THE POLEWARD CHANNEL HAS YET TO TAP INTO THE STRONG UPPER-LEVEL JET.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 05W IS EXPECTED TO CONTINUE TRACKING TO THE EAST-NORTHEAST
AROUND THE NORTHWESTERN PERIPHERY OF THE STEERING STR. AN UPPER-LEVEL
TROUGH LOCATED OVER EASTERN CHINA IS EXPECTED TO MODIFY THE STR
FURTHER AS TY 05W TRACKS TOWARDS JAPAN. MODEL GUIDANCE IS IN VERY
GOOD AGREEMENT THROUGH TAU 36, SHOWING TY 05W GRADUALLY WEAKENING AS
THE OVERALL ENVIRONMENT DETERIORATES.
THE WEAKENING TREND WILL BEGIN SLOWLY AS VERTICAL WIND SHEAR (VWS)
INCREASES AS TY 05W APPROACHES THE MID-LATITUDE FRONTAL BOUNDARY
ASSOCIATED WITH A LOW PRESSURE CIRCULATION CURRENTLY LOCATED OVER
NORTHEAST CHINA. AS THE LOW MOVES TOWARDS THE SEA OF JAPAN BETWEEN
TAU 24 AND 36, THE VWS IS EXPECTED TO FURTHER WEAKEN TY 05W. SEA
SURFACE TEMPERATURES (SSTS) HAVE BEEN FAVORABLE TO THIS POINT;
HOWEVER, THEY WILL SLOWLY DECREASE OVER THE NEXT 12 TO 24 HOURS,
GOING FROM 29 CELSIUS TO APPROXIMATELY 24 TO 26 CELSIUS BY TAU 24.
BEYOND TAU 24 SSTS REMAIN VERY UNFAVORABLE. THE MAJOR CONCERN WITH
THE FORECAST IS BEYOND TAU 36. THE FORECAST KEEPS THE TRACK TO THE
WEST OF TOKYO AS THE SYSTEM UNDERGOES EXTRA-TROPICAL TRANSITION
(ETT). MODEL GUIDANCE CONTINUES TO INDICATE A TRACK OVER KYOTO INTO
THE SEA OF JAPAN. THE THOUGHT PROCESS FOR THE FORECAST IS THAT MODEL
GUIDANCE IS TRACKING TOWARDS THE MID-LEVEL VORTICITY FIELDS, WHILE
THE LLCC IS EXPECTED TO TRACK ALONG THE STATIONARY FRONTAL BOUNDARY
LOCATED ALONG COASTAL JAPAN. LAND EFFECTS ON THE LLCC DURING THE ETT
PROCESS WILL CREATE A VERY DISORGANIZED STRUCTURE BETWEEN TAU 48 AND
72. THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK THROUGH TAU 36,
BUT DECREASES TO LOW BEYOND TAU 36 AS THE FORECAST TRACK DIFFERS FROM
THE MAJORITY OF MODEL GUIDANCE WITHIN THE CONSENSUS.//
NNNN

[senorpepr]

What does that translate out to in knots?

T5.0 is 90 knots, but since the storm is weakening, surface vorticity is conserved. That's why the CI is T5.5 or 102 kt.

FWIW, KNES generally agrees with me. 5.0 DT based on the light grey ring. Pattern and Model are also 5.0. Current intensity is held a little higher at 6.0 or 115 kt.

Honestly, this hasn't been a "super typhoon" for many hours.

JTWC was a bit higher: T5.5/6.5. So they'll keep it at 130 kt. They're seeing some banding feature to increase up to 5.5, but I don't see any that meet the requirements.


902
TXPQ28 KNES 172106
TCSWNP

A. 05W (GUCHOL)

B. 17/2032Z

C. 21.5N

D. 127.1E

E. ONE/MTSAT

F. T5.0/6.0/W1.0/24HRS

G. IR/EIR/SWIR

H. REMARKS...DT=5.0 BASED ON LG RING WITH OW EYE. PT=5.0. MET=5.0. FT
BASED ON DT.

I. ADDL POSITIONS

NIL


...SCHWARTZ




169
TPPN10 PGTW 172111

A. TYPHOON 05W (GUCHOL)

B. 17/2032Z

C. 21.5N

D. 127.2E

E. ONE/MTSAT

F. T5.5/6.5/W0.5/24HRS STT: W0.5/03HRS

G. IR/EIR

H. REMARKS: 05A/PBO IRREG EYE/ANMTN. OW EYE SURROUNDED BY LG
YIELDS AN E# AND CF (NO EYE ADJUSTMENT) OF 5.0. PLUS A SMALL
BANDING FEATURE YIELDS A DT OF 5.5. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE

[tolakram]

My favorite pic that I can find, from yesterday. Saved.

[brunota2003]

So I wasn't too far off on my guesstimate of 105 or 110 knots, then. Surprised JTWC still has it at 125 knots, though...it looks way weaker than that. Good example of why recon is important, I presume.

[tolakram]

Running out of warm water.

[senorpepr]

So I wasn't too far off on my guesstimate of 105 or 110 knots, then. Surprised JTWC still has it at 125 knots, though...it looks way weaker than that. Good example of why recon is important, I presume.

I'm a huge supporter of letting UAV recon take the load. Cheaper and less man-power requirements... I hope to see in the upcoming years UAV recon becoming a better leveraged tool.

[senorpepr]

193
TPPN11 PGTW 172127

A. TROPICAL DEPRESSION 06W (E OF HAINAN)

B. 17/2032Z

C. 18.5N

D. 111.6E

E. FIVE/MTSAT

F. T2.5/2.5/D1.5/21HRS STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS 0.45 ON LOG10
SPIRAL YIELDING A DT OF 2.5. THE 21HR MET YIELDS A MET OF 2.0.
PT AGREES. SBO DT.

I. ADDITIONAL POSITIONS: NONE


LANZETTA

[senorpepr]

WTPQ20 RJTD 172100
RSMC TROPICAL CYCLONE ADVISORY
NAME TY 1204 GUCHOL (1204)
ANALYSIS
PSTN 172100UTC 21.5N 127.2E GOOD
MOVE N 13KT
PRES 950HPA
MXWD 085KT
GUST 120KT
50KT 80NM
30KT 250NM SOUTHEAST 200NM NORTHWEST
FORECAST
24HF 182100UTC 28.1N 130.0E 85NM 70%
MOVE NNE 21KT
PRES 960HPA
MXWD 075KT
GUST 105KT
45HF 191800UTC 36.0N 135.6E 180NM 70%
MOVE NNE 25KT
PRES 980HPA
MXWD 055KT
GUST 080KT
69HF 201800UTC 41.6N 146.3E 250NM 70%
MOVE NE 29KT
PRES 992HPA
MXWD 045KT
GUST 065KT =

[brunota2003]

So I wasn't too far off on my guesstimate of 105 or 110 knots, then. Surprised JTWC still has it at 125 knots, though...it looks way weaker than that. Good example of why recon is important, I presume.

I'm a huge supporter of letting UAV recon take the load. Cheaper and less man-power requirements... I hope to see in the upcoming years UAV recon becoming a better leveraged tool.

Me too...and with one of the U.S.' large bases in the area, they could fly them straight out of Okinawa, couldn't they? We seem to have the big lead when it comes to recon, so I don't see why we couldn't assist.