WPAC: HAGIBIS - Post-Tropical

[Hayabusa]

Wow, it's already past 9Z but HWRF 6Z has it as 877 mb

[euro6208]

Ignoring SATCON


WDPN31 PGTW 090900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 20W (HAGIBIS) WARNING NR
017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 20W (HAGIBIS), LOCATED APPROXIMATELY 258
NM SOUTH-SOUTHWEST OF IWO TO, HAS TRACKED NORTH-NORTHWESTWARD AT
10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) DEPICTS A WELL-DEFINED, SYMMETRIC EYE WITH CONVECTIVE
BANDING WRAPPING INTO THE CENTER. STY 20W HAS MAINTAINED A 30 NM
DIAMETER EYE, SUPPORTING THE INITIAL POSITION WITH GOOD CONFIDENCE.
THE CIRRUS SHIELD AND WIDTH OF THE DEEP CONVECTIVE EYEWALL HAVE
CONTINUED TO THIN OVER THE PAST 6 HOURS. THE INITIAL INTENSITY IS
SET AT 140 KTS WITH FAIR CONFIDENCE BASED ON DVORAK CURRENT
INTENSITY (CI) ESTIMATES OF T7.0 (140 KTS) FROM PGTW AND RJTD, WHICH
IS BETWEEN A 090540Z AUTOMATED DVORAK TECHNIQUE ESTIMATE OF 132 KTS
AND A 090033Z SATCON ESTIMATE OF 154 KTS. UPPER-LEVEL ANALYSIS SHOWS
EXCELLENT EQUATORWARD AND EASTWARD OUTFLOW, AND A POLEWARD OUTFLOW
CHANNEL HAS DEVELOPED, TAPPING INTO A PASSING TROUGH TO THE NORTH.
THE OVERALL ENVIRONMENT REMAINS FAVORABLE FOR BRIEF DEVELOPMENT WITH
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS) AND WARM (29-31 CELSIUS)
SEA SURFACE TEMPERATURES (SST). STY 20W IS TRACKING NORTHWESTWARD
ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE LAST PROGNOSTIC REASONING MESSAGE.
B. STY 20W WILL CONTINUE ALONG ITS NORTH-NORTHWESTWARD TRACK AS A
PASSING MID-LATITUDE TROUGH TO THE NORTH CAUSES THE STR TO REORIENT.
THE FAVORABLE ENVIRONMENT IS EXPECTED TO PERSIST WITH LOW VWS, WARM
SST, AND STRONG UPPER-LEVEL OUTFLOW. STY 20W IS EXPECTED TO MAINTAIN
INTENSITY FOR THE FIRST 12 HOURS AS DIURNAL CONVECTIVE MINIMUM
COMPETES WITH ENHANCED POLEWARD OUTFLOW DUE TO THE TROUGH PASSING TO
THE NORTH. HOWEVER, STY 20W IS EXPECTED TO BEGIN A GRADUAL WEAKENING
TREND AFTER TAU 12 AS THE TROUGH BEGINS TO INTERFERE WITH OUTFLOW.
NUMERICAL MODELS REMAIN IN GOOD CROSS-TRACK AGREEMENT BUT POOR ALONG-
TRACK SPEED AGREEMENT. GFS AND THE GFS ENSEMBLE REMAIN THE
EASTERNMOST OUTLIERS WITH NAVGEM AS THE WESTERNMOST OUTLIER IN THE
SHORT TERM. AT TAU 72, THERE IS 90 NM OF CROSS-TRACK AND 230 NM OF
ALONG-TRACK SPREAD AS THE MODEL SOLUTIONS DIFFER IN TIMING OF
RECURVATURE. PLACED NEAR THE MULTI-MODEL CONSENSUS AND MAIN MODEL
GROUPING, THERE IS GOOD CONFIDENCE IN THE OFFICIAL JTWC FORECAST IN
THIS PORTION OF THE TRACK.
C. IN THE EXTENDED FORECAST PERIOD, STY 20W WILL BEGIN TO RECURVE
AS A SHORTWAVE TROUGH PASSES OVER JAPAN, WEAKENING THE STR. AS VWS
INCREASES AND SSTS DROP BELOW 26 DEGREES CELSIUS AFTER TAU 72, THE
SYSTEM WILL CONTINUE TO WEAKEN AS IT APPROACHES HONSHU. AS STY 20W
TRACKS OVER LAND, FRICTIONAL TERRAIN EFFECTS WILL ALSO BEGIN TO
ERODE THE SYSTEM. STY 20W WILL BEGIN INTERACTING WITH THE TROUGH
AROUND TAU 96, ACCELERATING NORTHEASTWARD AS EXTRATROPICAL
TRANSITION OCCURS. BY TAU 120, THE SYSTEM WILL BE FULLY
EXTRATROPICAL AND EMBEDDED IN THE MID-LATITUDE WESTERLIES. NUMERICAL
MODELS ARE IN FAIR CROSS-TRACK AGREEMENT AFTER RECURVATURE OF STY
20W. HOWEVER, AS THE SYSTEM ACCELERATES, ALONG-TRACK SPREAD GREATLY
INCREASES THROUGH TAU 120. ECMWF, NAVGEM, AND COAMPS-TC ARE SLOWER
THAN THE MULTI-MODEL CONSENSUS AT LATER TAUS. THE JTWC FORECAST
TRACK IS PLACED NEAR BUT SLIGHTLY SLOWER THAN THE MULTI-MODEL
CONSENSUS AFTER TAU 72. BASED ON THE VARIATION IN MODEL TIMING OF
THE RECURVE AND ALONG-TRACK SPEEDS, THERE IS LOW CONFIDENCE IN THIS
PORTION OF THE JTWC TRACK FORECAST.//
NNNN

[Hayabusa]

20W HAGIBIS 191009 1200 21.2N 139.6E WPAC 140 910

[1900hurricane]

Another eyewall replacement may be coming.

[Highteeld]

Another eyewall replacement may be coming.

https://i.imgur.com/3niMFSd.jpg

Sure looks like it. Would probably explain why the second peak of this storm wasn't as impressive as expected.

[NotoSans]

 https://twitter.com/philipslau681/status/1181947901691383808

[1900hurricane]

A RMW estimate under 35 km is unrealistic right now I think.

[1900hurricane]

This is probably going to look pretty spectacular once the sun comes up.

[Highteeld]

JTWC continues 140 knots

20W HAGIBIS 191009 1800 22.0N 139.8E WPAC 140 918

[CryHavoc]

This is probably going to look pretty spectacular once the sun comes up.

https://i.imgur.com/TM04hbS.gif

That eye is so impressively round. o_o

[1900hurricane]

JTWC continues 140 knots

20W HAGIBIS 191009 1800 22.0N 139.8E WPAC 140 918

Seems reasonable. I was actually wondering if they were going to drop to 135 kt since W has occasionally fallen below width requirements.

[1900hurricane]

This is probably going to look pretty spectacular once the sun comes up.

https://i.imgur.com/TM04hbS.gif

That eye is so impressively round. o_o

You can even see the low level clouds moving around in it. Pretty cool, but won't hold a candle to actual visible imagery!

[Highteeld]

JTWC continues 140 knots

20W HAGIBIS 191009 1800 22.0N 139.8E WPAC 140 918

Adjusted to 905 mb

20W HAGIBIS 191009 1800 22.0N 139.8E WPAC 140 905

[1900hurricane]

 https://twitter.com/1900hurricane/status/1182036195460751361

[Hayabusa]

[Highteeld]

It would appear to be intensifying

[mrbagyo]

[1900hurricane]

Looks like the outer eyewall feature has given up some, which is probably why the tops got colder again. NW side is a little weak, which matches with conventional imagery.

[Dylan]

 https://twitter.com/DylanFedericoWX/status/1182054129667121152

[Highteeld]

Looks like the outer eyewall feature has given up some, which is probably why the tops got colder again. NW side is a little weak, which matches with conventional imagery.

https://i.imgur.com/xq1Ygd2.jpg

Yeah. It was a weak eyewall to begin with... so the ERC failing isn't super surprising I guess.