WPAC: YUTU - Post-Tropical

[mrbagyo]

 https://twitter.com/iCyclone/status/1056293419817951233



This one is chaseable along the Aurora coast all the way up to Dinapigue. Been to Dilasag last week - Athena's lodge in the town proper can take it - solid concrete building with solid concrete slab roofing (that's where I stayed).
Chasing along Aurora coast is more challenging than going to Cagayan Valley - the road from Baler going up north (though forested) is still landslide/rockslide prone plus it's also mostly up and down zigzag rivaling that of Kennon in Baguio (and most sections still don't have side barriers!)

[Highteeld]

judging by the appearance of the eye as well as its temperature, i think the shear has calmed down quite a bit -- but OHC's have also cooled. Dynamics are probably better now than they were 12 hours ago, but the thermodynamics are lacking, as evidenced by the warming cloud tops. 24 hours from now should be interesting if the shear continues to abate.

[1900hurricane]

That seems to be a fair assessment. Much of the shear was being driven by a powerful upper level ridge. Now that Yutu is moving away from it, its influence is lessening. It's also worth noting that Yutu is actually fairly close to the old Trami upwelling spot right now, so that might be limiting top end convection right now.

[shah83]

It will likely be moving south of the upwelled area soon enough, though.

[doomhaMwx]

High-resolution satellite images from DigitalGlobe's WorldView-3 satellite showing the destruction left by STY Yutu in the islands of Tinian and Saipan.
https://www.washingtonpost.com/graphics ... struction/

[euro6208]

Track agreed and models indicating some renewed strengthening before landfall. How strong remains to be seen.

[Hayabusa]

31W YUTU 181028 0600 17.9N 129.0E WPAC 130 925


CIMSS TROPICAL CYCLONE INTENSITY CONSENSUS FOR YUTU (31W) 2018
CURRENT ESTIMATE
Date (mmddhhmm): 10280436
SATCON: MSLP = 916 hPa MSW = 135 knots
SATCON Member Consensus: 131.0 knots
Pressure -> Wind Using SATCON MSLP: 124 knots
Distance to Outer Closed Isobar Used is 200 nm
Eye Size Correction Used is -5.2 knots Source: IR

Member Estimates

ADT: 940 hPa 112 knots Scene: CDO Date: OCT280540
CIMSS AMSU: 907 hPa 145 knots Bias Corr: 0 (MW) Date: 10272201
ATMS: 904.7 hPa 148.2 knots Date: 10280436
SSMIS: 904.7 hPa 148.2 knots Date: 10280436
CIRA ATMS: 943 hPa 114 knots Date: 10260332

[dexterlabio]

Intensity and track were nailed by UKMET, I must say.

[mrbagyo]

Intensity and track were nailed by UKMET, I must say.

Agree.

[euro6208]

Closeup of the expected landfall, Isabela Province.

WDPN31 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 31W (YUTU) WARNING NR
28//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 31W (YUTU), LOCATED APPROXIMATELY 501 NM EAST-
NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 10 KNOTS
OVER THE PAST SIX HOURS. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A 45-NM RAGGED EYE IN ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) WHICH ALSO SHOWS THE DEEP CONVECTION HAS
ERODED ON THE EASTERN SIDE OF THE CYCLONE. THE INITIAL INTENSITY OF
130 KNOTS FOLLOWS MULTI-AGENCY DVORAK ESTIMATES OF T6.5-T7.0 (127-
140 KNOTS). THE ENVIRONMENT IS MARGINALLY FAVORABLE WITH LOW (10-15
KNOT) VERTICAL WIND SHEAR (VWS), GOOD RADIAL OUTFLOW, AND WARM SEA
SURFACE TEMPERATURE (28-29 CELSIUS) BEING OFFSET BY DRY AIR FROM THE
WEST WRAPPING AROUND TO THE EASTERN PERIPHERY OF THE CYCLONE. STY
31W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF AN EAST-WEST
ORIENTED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. STY 31W WILL CONTINUE TO TRACK WESTWARD TO WEST-SOUTHWESTWARD
TOWARD LUZON, MAKE LANDFALL SHORTLY AFTER TAU 36 AND RE-EMERGE INTO
THE SOUTH CHINA SEA (SCS) AFTER TAU 48. THE SYSTEM IS EXPECTED TO
WEAKEN TO 115 KNOTS PRIOR TO LANDFALL AS DRY AIR CONTINUES TO IMPACT
THE CYCLONE, WEAKEN SIGNIFICANTLY OVER LUZON, AND RE-INTENSIFY
SLIGHTLY IN THE SCS. THE INTENSITY FORECAST CLOSELY FOLLOWS THE HWRF
INTENSITY FORECAST, WHICH HAS A TRACK VERY SIMILAR TO THE JTWC
FORECAST TRACK. THE JTWC TRACK FORECAST IS CLOSE TO THE CONSENSUS
TRACK. WITH SPREAD IN THE MODELS OF ABOUT 150 NM AT TAU 72,
UNCERTAINTY IN THE JTWC TRACK FORECAST IS LOW FOR THIS PORTION OF
THE FORECAST.
C. BEYOND TAU 72, AN APPROACHING MID-LATITUDE TROUGH WILL WEAKEN
THE STR AND ALLOW STY 31W TO RECURVE NORTHWARD. ENVIRONMENTAL
CONDITIONS ARE EXPECTED TO BE MARGINALLY FAVORABLE WITH STRONG
RADIAL OUTFLOW BEING OFFSET BY HIGH VWS AND THE ENTRAINMENT OF COOL,
DRY AIR. EVERY NUMERICAL MODEL MEMBER IN THE CONSENSUS PREDICTS
RECURVATURE BUT, BY TAU 120, THE SPREAD IS ABOUT 400 NM DUE TO
DIFFERENCES IN THE TIMING AND DEGREE OF RECURVATURE. BASED ON THIS
SPREAD, UNCERTAINTY IS LOW IN THE EXTENDED PORTION OF THE JTWC
TRACK FORECAST.//
NNNN

[euro6208]

[TorSkk]

I'd go with 115 kn for 12Z

[Hayabusa]

31W YUTU 181028 1200 17.7N 128.1E WPAC 110 946

[NotoSans]

Convection on the eastern semicircle has started to wane.

[1900hurricane]

Looks like dry air might be the culprit.

[euro6208]

WDPN31 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 31W (YUTU) WARNING NR 30//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 31W (YUTU), LOCATED APPROXIMATELY 385 NM
EAST-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD
AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS UNRAVELING AND COLLAPSING RAIN BANDS FEEDING
INTO A CENTRAL CONVECTION THAT CONTINUED TO WEAKEN, AS EVIDENCED BY
WARMING CLOUD TOPS. THE SYSTEM, HOWEVER, HAS MAINTAINED A 30-NM
RAGGED EYE THAT LINED UP WELL WITH A MICROWAVE EYE IN THE 281721Z
AMSR2 PASS AND USED FOR THE INITIAL POSITION WITH HIGH CONFIDENCE.
THE INITIAL INTENSITY OF 105 KNOTS IS AVERAGED FROM AGENCY AND
OBJECTIVE DVORAK ESTIMATES RANGING FROM T5.0-T6.0. THE ENVIRONMENT
IS LESS FAVORABLE WITH REDUCED UPPER LEVEL OUTFLOW AND MODERATE (15-
20 KNOT) VERTICAL WIND SHEAR (VWS). HOWEVER, ALONG-TRACK SST AND OHC
VALUES REMAIN CONDUCIVE. TY 31W IS TRACKING ALONG THE SOUTHERN
PERIPHERY OF AN EAST-WEST ORIENTED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TY 31W WILL CONTINUE ON A WEST-SOUTHWESTWARD TRACK TOWARD LUZON
AS THE STR BUILDS, MAKE LANDFALL JUST SOUTH OF PALANAN, ISABELA
SHORTLY AFTER TAU 24, DRAG QUICKLY ACROSS THE RUGGED TERRAIN OF LUZON
AND EXIT INTO THE SOUTH CHINA SEA (SCS) JUST AFTER TAU 36. AFTERWARD,
A MID-LATITUDE SHORTWAVE TROUGH APPROACHING FROM THE NORTHWEST WILL
WEAKEN THE STR AND ALLOW THE CYCLONE TO TRACK NORTHWESTWARD. DUE TO
THE DEGRADED ENVIRONMENT, THE SYSTEM WILL CONTINUE TO SLOWLY WEAKEN
TO 95 KNOTS BEFORE LANDFALL, THEN RAPIDLY ERODE TO 60 KNOTS BY TAU 36
DUE TO LAND INTERACTION AND INCREASING VWS AS IT EXITS INTO THE SOUTH
CHINA SEA. AFTERWARD, INCREASED POLEWARD OUTFLOW AHEAD OF THE
SHORTWAVE TROUGH WILL OFFSET THE MARGINAL ENVIRONMENT AND STOKE A
SLIGHT INTENSIFICATION TO 70 KNOTS BY TAU 72. NUMERICAL GUIDANCE IS
IN TIGHT AGREEMENT WITH MINIMAL SPREADING TO 120 NM AT TAU 72,
LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST THAT IS
LAID VERY CLOSE TO CONSENSUS.
C. BEYOND TAU 72, TY YUTU WILL CREST THE STR AXIS AND TRACK MORE
NORTHWARD. INCREASING VWS AND A COLD SURGE EVENT IN THE SCS WILL
GRADUALLY ERODE THE SYSTEM DOWN TO 45 KNOTS BY TAU 120. NUMERICAL
MODEL GUIDANCE AGREEMENT CONTINUES TO TIGHTEN WITH GRADUAL SPREADING
TO 290 NM AT TAU 120. NOTABLE LEFT-OF-TRACK OUTLIERS ARE GFS AND JGSM
FAVORING A DELAYED, WIDER RECURVATURE. THERE IS FAIR CONFIDENCE IN
THE EXTENDED PORTION OF THE JTWC FORECAST TRACK THAT IS LAID JUST
RIGHT OF CONSENSUS TO OFFSET THE LESS LIKELY LEFTWARD MODEL
OUTLIERS.//
NNNN

[mrbagyo]

Looks like an ERC is commencing.
It would be interesting to see if the high OHC / SST can offset the dry air hounding it.

[Hayabusa]

31W YUTU 181029 0000 16.9N 126.2E WPAC 90 956

TY 1826 (Yutu)
Issued at 00:40 UTC, 29 October 2018

<Analysis at 00 UTC, 29 October>
Scale -
Intensity Very strong
Center position N17°00' (17.0°)
E126°05' (126.1°)
Direction and speed of movement WSW 20 km/h (10 kt)
Central pressure 950 hPa
Maximum wind speed near center 45 m/s (85 kt)
Maximum wind gust speed 60 m/s (120 kt)
≥ 50 kt wind area ALL 130 km (70 NM)
≥ 30 kt wind area NW 480 km (260 NM)
SE 330 km (180 NM)

[ManilaTC]

Looks like it has finished ingesting dry air. Its reorganizing its back side convective activity...

[mrbagyo]

 https://twitter.com/iCyclone/status/1056717584995889156