WPAC: SURIGAE - Post-Tropical

[Hayabusa]

Most members now offshore, you know unless Surigae decides to have a mind on its own

[aspen]

That is a huge outer eyewall, and it’s already very well defined. Maybe Surigae actually could finish its EWRC before running out of warm water; it just needs to fully degrade what’s left of the inner eyewall.

[JW-_-]

[WAcyclone]

Interestingly, there were actually two separate SMAP passes on 17 April, both yielding the exact same windspeed.

The first one at 0921Z yielded 148.4 kt (10-minute, use your preferred conversion factor to calculate the 1-minute windspeed )
BD Enhancement image this time:




The second pass at 2133Z yielded 148.2 kt, yet the BD image looks significantly weaker at this time:



However, I think there is something interesting to point out here. SMAP has a resolution of 39 × 47 km which means there is usually just one or two pixels actually showing very high windspeed values. This was indeed the case with the 2133Z pass which had two pixels at 140+ kt. In the 0921Z pass, however, there were four pixels all showing basically the same value of 145-148 kt. Even in very large-eyed systems it is quite rare to see the max windspeed captured by that many pixels. Maybe there was some undersampling going on in that 0921Z pass?

[JW-_-]

A great storm this one but Tip still remains the greatest I have ever seen of all time in this basin.

[euro6208]

Immense ocean heat available for Surigae. One of the reasons why It became so historically intense.

[euro6208]

The list of category 5 typhoons for the months of January-April with 9 storms. Surigae blisters them all.

Surigae, 190 mph winds, Apr. 17, 2021;
Hester, 185 mph winds, Jan. 1, 1953;
Maysak, 175 mph winds, Mar. 31, 2015;
Thelma, 175 mph winds, Apr. 20, 1956;
Wutip, 165 mph winds, Feb. 23, 2019;
Isa, 165 mph winds, Apr. 20, 1997;
Mitag, 160 mph winds, Mar. 5, 2002;
Andy, 160 mph winds, Apr. 21, 1989;
Ophelia, 160 mph winds, Jan. 13, 1958.

[mrbagyo]

EWRC is almost done

[dexterlabio]

As much as I thought Surigae is a one of a kind Cat5, I still don't think it potentially surpassed Goni at peak strength, especially if we consider Goni's pre-EWRC pinhole-eyed phase.

[JW-_-]

Without planes, those are always going to be the million-dollar questions with high-end v/intense systems. Without that type of data, we will never
know if a system has exceeded the max vorticity records of others. That said there are some excellent people on this site @ estimating with satellite dvorak intensity analysis

[mrbagyo]

As much as I thought Surigae is a one of a kind Cat5, I still don't think it potentially surpassed Goni at peak strength, especially if we consider Goni's pre-EWRC pinhole-eyed phase.

I also think Goni had a more compressed pressure gradient due to the ridge to its north that eventually led it to take a WSW course towards the Philippines.

[mrbagyo]

Can we throw in the "A-word" now?


edit: not yet

[euro6208]

WDPN31 PGTW 180900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 02W (SURIGAE) WARNING
NR 020//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON 02W (SURIGAE), LOCATED APPROXIMATELY 367 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 06 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS SIGNIFICANTLY WARMED CONVECTIVE TOPS OVER AN ENLARGED
CENTRAL DENSE OVERCAST AND UNRAVELING OF FEEDER BANDS. THE EYE,
APPROXIMATELY 10NM IN DIAMETER, HAS BECOME PARTIALLY FILLED BUT
REMAINS DISCERNIBLE AND LENDS HIGH CONFIDENCE IN THE INITIAL
POSITION. IT APPEARS THAT EYEWALL REPLACEMENT HAS COMPLETED AS
EVIDENCED BY THE DISAPPEARANCE OF THE MOAT FEATURE IN THE 180515Z
AMSR2 89GHZ IMAGE. A MICROWAVE EYE IS ALSO EVIDENT IN THE AMSR2
IMAGE AND LINED UP PERFECTLY WITH THE EIR EYE. THE INITIAL INTENSITY
OF 135KTS IS BASED ON THE HIGHER END OF WEAKENING AGENCY DVORAK
FINAL-T ESTIMATES FROM PGTW, RJTD, AND KNES OF T6.5/127KTS; AND THE
OBJECTIVE ESTIMATE OF T6.6/130KTS FROM ADT. ANALYSIS INDICATES THE
ENVIRONMENT HAS BECOME LESS FAVORABLE WITH THE LOW (5-10KT) VERTICAL
WIND SHEAR (VWS) AND WARM (29-30C) SEA SURFACE TEMPERATURES (SSTS)
IN THE PHILIPPINE SEA OFFSET BY DIMINISHING POLEWARD OUTFLOW THAT IS
SUPPRESSED BY THE MIDLATITUDE TROUGH TO THE NORTH. THE CYCLONE IS
TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR)
TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. STY 02W WILL TRACK MORE TO THE NORTH-NORTHWEST AS THE STR
ELONGATES MERIDIONALLY. THE DIMINISHING OUTFLOW OFFSETTING THE LOW
VWS AND WARM SSTS WILL PRIMARILY BE RESPONSIBLE FOR ITS GRADUAL
WEAKENING, DOWN TO 95KTS BY TAU 72. NUMERICAL MODELS ARE IN GOOD
AGREEMENT WITH A GRADUAL AND EVEN CROSS-TRACK SPREAD TO 176NM BY TAU
72, LENDING FAIR CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST
TRACK, WHICH IS LAID CLOSE TO THE MULTI-MODEL CONSENSUS.
C. AFTER TAU 72, STY SURIGAE WILL CREST THE STR AXIS AND BEGIN
ITS RECURVE ON THE POLEWARD SIDE, ACCELERATING NORTHEASTWARD.
INCREASING VWS WILL CONTRIBUTE TO A MORE RAPID DECAY, DOWN TO 75KTS
BY TAU 120. THE NUMERICAL MODELS CLUSTER CLOSER TO 130NM AT TAU 120,
LENDING ALSO FAIR CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC
TRACK FORECAST.//
NNNN

[mrbagyo]

Down to 125

02W SURIGAE 210418 1200 13.6N 126.8E WPAC 125 932

[Hayabusa]

A bit late but UKMET 00Z init it as 888 mb

0000UTC 18.04.2021 0 13.0N 127.6E 888 131

[mrbagyo]

looks like upwelling is now taking its toll on Surigae, convection is starting to look anemic in comparison to yesterday

[Hayabusa]

Today's 12Z AMSU estimate

CIMSS AMSU: 899 hPa 160 knots Bias Corr: 0 (MW) Date: 04181258

CIMSS/NESDIS-USAF/NRL AMSU TC Intensity Estimation:
SUPER TYPHOON 02W
Sunday 18apr21 Time: 1258 UTC
Latitude: 14.49 Longitude: 125.87
Storm position corresponds to AMSU-A FOV 19 [1<--->30]
-----------------------------------------------------------------
| Estimated MSLP: 899 hPa
| Estimated Maximum Sustained Wind: 160 kts
| Estimate Confidence: Good ( +/- 10mb +/- 12kts )
-----------------------------------------------------------------
Channel 8 (~150 hPa) Tb Anomaly: 6.96
Channel 7 (~250 hPa) Tb Anomaly: 7.15
RMW: 41 km
RMW Source is: MW
Environmental Pressure: 1007
Satellite: NOAA-90
ATCF data for Month: 04 Day: 17 Time (UTC): 1800

For imagery, go to http://amsu.ssec.wisc.edu
For all comments and questions mailto:chrisv@ssec.wisc.edu

[Hayabusa]

If this large eye could clear out...

[mrbagyo]

9



mesovortices inside the mega eye?

[InfernoFlameCat]

Almost Annular. Spiral bands still somewhat hanging on however. This is a massive radius of maximum winds if the eye clears out or it could pull a Teddy.