WPAC: YUTU - Post-Tropical

[Highteeld]

Top Gradient (Delta Eye/CDO) Haiyan:

2013NOV07 190000 7.5 901.4 155.0 7.5 7.5 7.5 NO LIMIT OFF OFF 21.82 -84.60 EYE 24 IR 101.2 10.72 -126.43 COMBO MTSAT1 20.2

Top Gradient Nida:

2009NOV25 100100 7.7 874.2/ +3.6 /161.0 7.7 7.5 8.0 3.2T/18hr OFF OFF 21.61 -83.45 EYE 20 IR 32.10 12.38 -142.34 COMBO

Top Gradient Yutu:

2018OCT24 114000 7.5 898.3 155.0 7.5 7.8 7.9 1.3T/6hr OFF OFF OFF OFF 22.88 -81.02 EYE 21 IR 71.4 14.65 -146.25 ARCHER HIM-8 18.3

Top Gradient Meranti:

2016SEP12 143000 7.1 919.6 143.0 7.0 7.0 7.0 NO LIMIT ON OFF 23.82 -76.83 EYE 15 IR 82.0 19.20 -127.43 COMBO HIM-8 27.3

I'd probably agree with CrazyC83 that Yutu was around 160 knots at landfall, but I do think it was weakening then --> I'd put the peak at 13 UTC with winds at 165-170 knots.

[Hayabusa]

Dr. Maue's 170 knot prediction is after passing the islands, we shall see.

[mrbagyo]

Top Gradient (Delta Eye/CDO) Haiyan:

2013NOV07 190000 7.5 901.4 155.0 7.5 7.5 7.5 NO LIMIT OFF OFF 21.82 -84.60 EYE 24 IR 101.2 10.72 -126.43 COMBO MTSAT1 20.2

Top Gradient Yutu:

2018OCT24 114000 7.5 898.3 155.0 7.5 7.8 7.9 1.3T/6hr OFF OFF OFF OFF 22.88 -81.02 EYE 21 IR 71.4 14.65 -146.25 ARCHER HIM-8 18.3

Top Gradient Meranti:

2016SEP12 143000 7.1 919.6 143.0 7.0 7.0 7.0 NO LIMIT ON OFF 23.82 -76.83 EYE 15 IR 82.0 19.20 -127.43 COMBO HIM-8 27.3

I'd probably agree with CrazyC83 that Yutu was around 160 knots at landfall, but I do think it was weakening then --> I'd put the peak at 13 UTC with winds at 165-170 knots.

Haiyan is the only TC I'm aware of that surpassed a ∆ of 105 on Geostationary satellite imagery.

[Highteeld]

Top Gradient (Delta Eye/CDO) Haiyan:

2013NOV07 190000 7.5 901.4 155.0 7.5 7.5 7.5 NO LIMIT OFF OFF 21.82 -84.60 EYE 24 IR 101.2 10.72 -126.43 COMBO MTSAT1 20.2

Top Gradient Yutu:

2018OCT24 114000 7.5 898.3 155.0 7.5 7.8 7.9 1.3T/6hr OFF OFF OFF OFF 22.88 -81.02 EYE 21 IR 71.4 14.65 -146.25 ARCHER HIM-8 18.3

Top Gradient Meranti:

2016SEP12 143000 7.1 919.6 143.0 7.0 7.0 7.0 NO LIMIT ON OFF 23.82 -76.83 EYE 15 IR 82.0 19.20 -127.43 COMBO HIM-8 27.3

I'd probably agree with CrazyC83 that Yutu was around 160 knots at landfall, but I do think it was weakening then --> I'd put the peak at 13 UTC with winds at 165-170 knots.

Haiyan is the only TC I'm aware of that surpassed a ∆ of 105 on Geostationary satellite imagery.

Yep. It's almost unfathomable to think about how intense that storm was.

[mrbagyo]

Oops I forgot the monster from 2009 - super typhoon Nida. Difference was also above 105

[Highteeld]

Here are the two best AVN images I can find from Yutu... included Haiyan as the third.






Goddamn Haiyan... lol

[Hayabusa]

[Highteeld]

Oops I forgot the monster from 2009 - super typhoon Nida. Difference was also above 105

Nida:
2009NOV25 100100 7.7 874.2/ +3.6 /161.0 7.7 7.5 8.0 3.2T/18hr OFF OFF 21.61 -83.45 EYE 20 IR 32.10 12.38 -142.34 COMBO

[Highteeld]

 https://twitter.com/LaurSpohr/status/1055262808273707008

[Hayabusa]

Down to 145
31W YUTU 181025 0000 15.8N 144.2E WPAC 145 911

[euro6208]

WDPN31 PGTW 242100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 31W (YUTU) WARNING NR
14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 31W (YUTU), LOCATED APPROXIMATELY 30 NM
WEST-NORTHWEST OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
SHOWS A WELL DEFINED EYE WITH DEEP CONVECTION AROUND IT. HOWEVER, THE
COLDEST CLOUD TOPS HAVE SLIGHTLY WARMED OVER THE PAST SEVERAL HOURS.
THE INITIAL POSITION IS BASED ON A 241800Z HIMAWARI INFRARED
SATELLITE IMAGE WHICH SHOWS THE 20NM WIDE EYE. THE INITIAL INTENSITY
OF 150 KNOTS IS HEDGED SLIGHTLY BELOW DVORAK CURRENT INTENSITY (CI)
ESTIMATES OF T7.5 (155 KNOTS) FROM PGTW, RJTD, AND KNES BASED ON A
241608Z AMSR2 89GHZ MICROWAVE IMAGE SHOWING CONCENTRIC EYEWALLS
INDICATING AN EYEWALL REPLACEMENT CYCLE (ERC). ENVIRONMENTAL ANALYSIS
SHOWS STY 31W IS EXPERIENCING FAVORABLE VERTICAL WIND SHEAR (10 TO 15
KNOTS) AND HAS EXCELLENT RADIAL OUTFLOW. SEA SURFACE TEMPERATURES
ALSO REMAIN FAVORABLE, NEAR 30 DEGREES CELSIUS. STY 31W IS TRACKING
ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) LOCATED
TO THE NORTHEAST AND THE SOUTHEASTERN PERIPHERY OF AN STR LOCATED TO
THE NORTHWEST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. HOWEVER, MAXIMUM SIGNIFICANT
WAVE HEIGHT HAS BEEN LOWERED TO 30 FEET BASED ON A 241211Z ALTIMETRY
PASS SHOWING 27 FEET SOUTH OF TINIAN.
B. THE CURRENT ERC WILL RESULT IN A SLIGHT WEAKENING IN THE SHORT
TERM. STY 31 WILL CONTINUE TO TRACK TO THE NORTHWEST WHILE POSITIONED
BETWEEN THE AFOREMENTIONED STRS. MODEL GUIDANCE REMAINS IN FAIRLY
GOOD AGREEMENT THOUGH TAU 24, INDICATING A NORTHWESTWARD TRACK, BUT
QUICKLY DIVERGES AFTER THAT WITH A SPREAD OF 380 NM BY TAU 72. AT TAU
72 JGSM IS THE OUTLIER TO THE SOUTHWEST INDICATING A WESTWARD TRACK
WITH NVGM THE OUTLIER TO THE NORTHEAST INDICATING A RECURVE SCENARIO.
THE JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS IN
THE MIDDLE GROUP OF A TRIFURCATION, FAVORING THE ECMWF AND GFS
TRACKERS. DUE TO WIDE SPREAD IN MODEL GUIDANCE THERE IS LOW
CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.
C. BEYOND TAU 72 THE TRIFURCATION IN THE MODELS CONTINUES. JGSM,
EGRR, AND AFUM INDICATE A WEST-SOUTHWESTWARD TRACK WITH NVGM AND CTCX
INDICATING A NORTHEASTWARD TRACK. ECMWF, GFS, AND HWRF INDICATE A
NORTHWESTWARD TRACK. NVGM AND EGRR ARE AT THE EDGES OF THE MODEL
ENVELOPE AND HAVE A MASSIVE SPREAD OF NEARLY 1900 NM BY TAU 120. THE
JTWC FORECAST TRACK IS PLACED TO THE SOUTHWEST OF THE MULTI-MODEL
CONSENSUS, FAVORING THE GFS AND ECMWF SOLUTIONS. DUE TO THE WIDE
SPREAD IN MODEL GUIDANCE THERE IS LOW CONFIDENCE IN THIS PORTION OF
THE JTWC FORECAST TRACK.//
NNNN

[Hayabusa]

JMA-GSM model predicts 862 mb peak at 120 tau

[1900hurricane]

Something looks off with eyewall replacement. It appears the outer eyewall has fragmented a little bit. Perhaps environmental dry air has played a part?

[Hayabusa]

[euro6208]

I'm surprise none of the typhoon chasers, James, Jim, and Josh, didn't chase this. It would have been incredible to get the pressure out of this. Yutu surely caught everyone off guard, as a high end Cat 5 landfall.

[1900hurricane]

Here's the 12Z Guam sounding from the 24th, the launch when Yutu was nearest to the sounding site. Data only extends up to 100 mb, but the temperature there is -87.5ºC at over 16.5 km up. Equilibrium Level and it appears the tropopause actually extends up beyond that point in the sounding.



 https://twitter.com/1900hurricane/status/1055285523810603008

[mrbagyo]

I think if ERC didn't happen, Yutu should have had a full CDG before the passage.

[wxmann_91]

Something looks off with eyewall replacement. It appears the outer eyewall has fragmented a little bit. Perhaps environmental dry air has played a part?

[microwave image]

Might be some easterly shear too. Satellite loops indicate the outflow to the east is being restricted, and in fact the GFS is showing easterly shear increasing to ~20 kt the next couple of days.

[Hayabusa]

3700 km model spread

WDPN31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 31W (YUTU) WARNING NR
15//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 31W (YUTU), LOCATED APPROXIMATELY 99 NM
WEST-NORTHWEST OF SAIPAN, HAS TRACKED WEST-NORTHWESTWARD AT 12 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS STY 31W HAS MAINTAINED A WELL DEFINED EYE WITH DEEP CONVECTION
SURROUNDING IT. THE INITIAL POSITION IS BASED ON A 250000Z HIMAWARI
VISIBLE SATELLITE IMAGE WHICH SHOWS THE 20NM WIDE EYE. THE INITIAL
INTENSITY OF 145 KNOTS IS BASED ON A SLIGHT WEAKENING TREND DUE TO AN
EYEWALL REPLACEMENT CYCLE AND IS HEDGED BETWEEN DVORAK CURRENT
INTENSITY (CI) ESTIMATES OF T7.5 (155 KNOTS) FROM PGTW, RJTD, AND
KNES, AND AN ADT CI OF T7.0 (140 KNOTS). ENVIRONMENTAL ANALYSIS SHOWS
STY 31W IS EXPERIENCING MODERATE VERTICAL WIND SHEAR (15 TO 20 KNOTS)
AND HAS NEAR RADIAL OUTFLOW. SEA SURFACE TEMPERATURES ALSO REMAIN
FAVORABLE, NEAR 30 DEGREES CELSIUS. STY 31W IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE
NORTHEAST AND THE SOUTHEASTERN PERIPHERY OF AN STR LOCATED TO THE
NORTHWEST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 72, STY 31W WILL CONTINUE TO TRACK TO THE
WEST-NORTHWEST WHILE POSITIONED BETWEEN THE AFOREMENTIONED STRS.
MODEL GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT THOUGH TAU 24,
INDICATING A WEST-NORTHWESTWARD TRACK, BUT QUICKLY DIVERGES AFTER
THAT WITH A SPREAD OF 470 NM BY TAU 72. AT TAU 72, JGSM IS THE
OUTLIER TO THE SOUTHWEST INDICATING A WESTWARD TRACK WITH NVGM THE
OUTLIER TO THE NORTHEAST INDICATING A RECURVE SCENARIO. THE JTWC
FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS IN THE MIDDLE
GROUP OF A TRIFURCATION, FAVORING THE ECMWF, HWRF, AND GFS TRACKERS.
DUE TO THE WIDE SPREAD IN MODEL GUIDANCE THERE IS LOW CONFIDENCE IN
THIS PORTION OF THE JTWC FORECAST TRACK.
C. BEYOND TAU 72, THE TRIFURCATION IN THE MODELS BECOMES EVEN MORE
PRONOUNCED. JGSM, EGRR, AND AFUM INDICATE A WEST-SOUTHWESTWARD TRACK
WITH NVGM AND CTCX INDICATING A NORTHEASTWARD TRACK. ECMWF, GFS, AND
HWRF INDICATE A WEST-NORTHWESTWARD TRACK AND A DECREASE IN FORWARD
SPEED NEAR TAU 96. NVGM AND JGSM REMAIN AT THE EDGES OF THE MODEL
ENVELOPE AND HAVE A MASSIVE SPREAD OF 2010 NM BY TAU 120. THE JTWC
FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS, FAVORING THE
GFS, HWRF AND ECMWF SOLUTIONS. DUE TO THE WIDE SPREAD IN MODEL
GUIDANCE THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST
TRACK.//
NNNN

[Hayabusa]

 https://twitter.com/RyanMaue/status/1055294554319011840