WPAC: SURIGAE - Post-Tropical

[CrazyC83]

Unfortunately we will never know the true intensity without Recon. My guess is the peak intensity was 170 kt at 12Z, and it's probably weakened some since (maybe 155 kt now).

[Hayabusa]

What a record that's on par and even better than the monster typhoons of peak season, I wonder now if peak season this year would try to beat this

[mrbagyo]

[Hayabusa]

JTWC didn't say this during Goni

THE INITIAL INTENSITY OF 165KTS IS BASED ON A
CONSENSUS OF MULTIPLE AGENCY DVORAK FINAL-T ESTIMATES RANGING FROM
T7.5 TO T8.0 (155-170KTS) PGTW, KNES, RJTD; AND THE OBJECTIVE
ESTIMATES OF T8.0/170KTS (ADT) AND 164KTS (SATCON), ALL REFLECTING
THE EXTREMELY INTENSE SYSTEM.

[doomhaMwx]

Crazy that an April TY might hold on to the crown for strongest TY this 2021 and is one of WPAC's strongest (most of which formed during Sept-Nov). The only other sub-900mb TY so early in the year is Amy on May 2, 1971: 890mb by JMA (JTWC 150kt).

[aspen]

Crazy that an April TY might hold on to the crown for strongest TY this 2021 and is one of WPAC's strongest (most of which formed during Sept-Nov). The only other sub-900mb TY so early in the year is Amy on May 2, 1971: 890mb by JMA (JTWC 150kt).

https://i.imgur.com/pY7YEH4.png

It’s not wise to give the tropics such a challenge lol

[Hayabusa]

[euro6208]

Record breaker


WDPN31 PGTW 172100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 02W (SURIGAE) WARNING
NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON 02W (SURIGAE), LOCATED APPROXIMATELY 448NM EAST-
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY SHOWS AN INVARIABLY SYMMETRICAL SYSTEM WITH A
CENTRAL DENSE OVERCAST (CDO) MAINTAINING A SHARPLY OUTLINED 12-NM
EYE. THE VERY ROBUST AND TIGHTLY COMPACT SYSTEM HAS SPIRALED TIGHTER
INTO THE CDO, INDICATING IT HAS POTENTIALLY REACHED ITS PEAK
INTENSITY. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE OVER
THE WELL-DEFINED EYE. THE INITIAL INTENSITY OF 165KTS IS BASED ON A
CONSENSUS OF MULTIPLE AGENCY DVORAK FINAL-T ESTIMATES RANGING FROM
T7.5 TO T8.0 (155-170KTS) PGTW, KNES, RJTD; AND THE OBJECTIVE
ESTIMATES OF T8.0/170KTS (ADT) AND 164KTS (SATCON), ALL REFLECTING
THE EXTREMELY INTENSE SYSTEM. ENVIRONMENTAL ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT WITH ROBUST RADIAL OUTFLOW, LOW TO MODERATE
(10-15 KTS) VERTICAL WIND SHEAR, AND WARM (29-30C) SEA SURFACE
TEMPERATURES IN THE PHILIPPINE SEA. STY 02W IS TRACKING TOWARD A
BREAK IN THE RIDGE TO THE NORTH-NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. STY 02W WILL TRACK TO THE NORTHWEST AS THE AFOREMENTIONED
SPLIT IN THE SUBTROPICAL RIDGE (STR) TO THE NORTH-NORTHEAST BUILDS
AND TAKES OVER AS THE MAIN STEERING RIDGE DURING THE NEXT 12 HOURS.
AT THIS SAME TIME, THE SYSTEM WILL BEGIN DECREASING IN INTENSITY AS
IT ENCOUNTERS A REGION OF HIGHER SHEAR (20-25KTS) TO THE NORTH. AS
STY SURIGAE APPROACHES THE RIDGE AXIS, THE NORTHWARD TRAJECTORY WILL
SLOW AS IT ENTERS A SLIGHTLY WEAKER STEERING ENVIRONMENT. AS THE
SYSTEM GAINS LATITUDE, DIVERGENCE ALOFT WILL DECREASE, SHEAR WILL
INCREASE, AND CAUSE THE SYSTEM TO WEAKEN DOWN TO 110KTS BY TAU 48.
NUMERICAL MODELS ARE IN FAIR AGREEMENT DURING THIS PORTION OF THE
FORECAST WITH A GRADUAL AND EVEN CROSS-TRACK SPREAD TO 148NM AT TAU
48. THEREFORE, THERE IS FAIR CONFIDENCE IN THIS PORTION OF THE JTWC
FORECAST TRACK, WHICH IS LAID OVER BUT SLIGHTLY SLOWER THAN THE
MULTI-MODEL CONSENSUS DURING THE SLOW PROGRESSION DURING THE WEAK
STEERING SEGMENT. THE CROSS TRACK ERROR DIVERGES SLIGHTLY GREATER TO
180NM BY TAU 72 AS INDICATED BY THE FAR LEFT OUTLIER OF NVGM AND THE
FAR RIGHT OUTLIER OF JGSM.
C. AFTER TAU 72, STY SURIGAE WILL BEGIN TO RECURVE TO THE
NORTHEAST ALONG THE WESTERN PERIPHERY OF THE STR, CREST THE AXIS,
THEN ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE. AS IT MOVES
FURTHER NORTH, THE ENVIRONMENT WILL CONTINUE TO BE LESS FAVORABLE AS
UPPER LEVEL DIVERGENCE DECREASES LEADING TO A NATURAL WEAKENING OF
THE SYSTEM TO 75KTS BY TAU 120. NUMERICAL MODELS HAVE CLUSTERED
CLOSER, WITH NVGM AS THE ONLY TRACK MEMBER AIMING TOWARDS LUZON AT
TAU 96. ALL OTHER MODELS REMAIN WELL TO THE EAST OF THE ISLAND AND
CONTINUE THE TRACK TO THE NORTHEAST. THE CROSS TRACK SPREAD IS NOW
DOWN TO 425NM AT TAU 120, LENDING FAIR CONFIDENCE IN THE EXTENDED
PORTION OF THE JTWC TRACK FORECAST.//
NNNN

[doomhaMwx]

 https://twitter.com/splillo/status/1383531246555328526

[JW-_-]

Seems the old school ens using potential intensity and a nondimensional measure of mid-tropospheric specific humidity x as variables
were in ballpark with this system.

[Hayabusa]

Since JMA rated it as 120 knots, that translates to 170 knots 1 min.

TY2102(Surigae)
Issued at 2021/04/17 21:45 UTC
Analisys at 04/17 21 UTC
Category TY
Scale -
Intensity Violent
Center Position N13°0′(13.0°)
E128°5′(128.1°)
Direction and speed of movement NW 20km/h(11kt)
Central pressure 895hPa
Maximum wind speed near the center 60m/s(120kt)
Maximum wind gust speed 85m/s(170kt)
50-kt wind area E280km(150NM)
W220km(120NM)
30-kt wind area WIDE390km(210NM)
Forecast at 04/18 21 UTC
Category TY
Intensity Violent
Center of probability circle N14°20′(14.3°)
E126°50′(126.8°)
Direction and speed of movement NW Slowly
Central pressure 895hPa
Maximum wind speed near the center 60m/s(120kt)
Maximum wind gust speed 85m/s(170kt)
Radius of probability circle 95km(50NM)
Storm warning area E370km(200NM)
W310km(170NM)

[euro6208]

Strongest April typhoon on record

Strongest Pre-June TC on record in the Northern Hemisphere.

The 5th typhoon since 2010 to achieve a CI of 8.0

2nd 8.0 typhoon in 6 months.

What a record breaker. Now if only we have those planes...return...

[mrbagyo]

The inner eye is filling up

[Hayabusa]

Also it's the first time since Meranti JMA gave a sub 900 mb pressure and in April at that!

[euro6208]

Unfortunately we will never know the true intensity without Recon. My guess is the peak intensity was 170 kt at 12Z, and it's probably weakened some since (maybe 155 kt now).

JTWC has an irrational fear of analyzing storms as being stronger than 170kts. I'd go with 175 to as high as 185 knots. Leaning more to 180 knots.

[ElectricStorm]

Unfortunately we will never know the true intensity without Recon. My guess is the peak intensity was 170 kt at 12Z, and it's probably weakened some since (maybe 155 kt now).

JTWC has an irrational fear of analyzing storms as being stronger than 170kts. I'd go with 175 to as high as 185 knots. Leaning more to 180 knots.

Nah I wouldn't go that high. I would go 165-170kts. Similar to Goni

[JW-_-]

Philippines sea is always with elnino like conditions SST wise. Everything else just gelled together.These days across the NH just entry-level cat5's
are becoming a thing of the past

[Hayabusa]

If Surigae could complete that erc soon, it may have a secondary peak.
Look at that almost came close to the theoretical MPI

02W
TYPHOON 02W 18:00UTC 17April2021
UW-CIMSS Experimental Vertical Shear and TC Intensity Trend Estimates

Current Conditions (from JTWC) :
Latitude : 12:39:43 N
Longitude : 128:15:51 E
Intensity (MSLP) : 879.0 hPa

Max Pot Int (MPI,from Emanuel) : 858.0 hPa
MPI differential (MSLP-MPI) : 21.0 hPa

CIMSS Vertical Shear Magnitude : 7.8 m/s (15.1 kts)
Direction : 91.5 deg

Outlook for TC Intensification Based on Current
Env. Shear Values and MPI Differential
Forecast Interval : 6hr 12hr 18hr 24hr
N N N N

Legend : VF-Very Favorable F-Favorable N-Neutral
U-Unfavorable VU-Very Unfavorable

-- Mean Intensity Trend (negative indicates TC deepening) --
6hr 12hr 18hr 24hr
VF <-3.0mb/ 6hr <-6.0mb/12hr <-9.0mb/18hr <-12.0mb/24hr
F -3.0 - -1.5 -6.0 - -3.0 -9.0 - -4.5 -12.0 - -6.0
N -1.5 - +1.5 -3.0 - +3.0 -4.5 - +4.5 -6.0 - +6.0
U +1.5 - +3.0 +3.0 - +6.0 +4.5 - +9.0 +6.0 -+12.0
VU >+3.0 >+6.0 >+9.0 >+12.0

[Subtrop]

02W SURIGAE 210418 0000 13.2N 127.7E WPAC 150 911

[Iceresistance]

JTWC didn't say this during Goni

THE INITIAL INTENSITY OF 165KTS IS BASED ON A
CONSENSUS OF MULTIPLE AGENCY DVORAK FINAL-T ESTIMATES RANGING FROM
T7.5 TO T8.0 (155-170KTS) PGTW, KNES, RJTD; AND THE OBJECTIVE
ESTIMATES OF T8.0/170KTS (ADT) AND 164KTS (SATCON), ALL REFLECTING
THE EXTREMELY INTENSE SYSTEM.

Goni was harder to forecast because of a Pinhole Eye