WPAC: SURIGAE - Post-Tropical

[mrbagyo]

Storm surge in Puraran Beach, Baras, Catanduanes

[mrbagyo]

[StormTracker89]

Quite the difference between JTWC and JMA
02W SURIGAE 210419 0000 14.3N 126.3E WPAC 125 931

And it would appear that JTWC is correct. 2122Z SAR pass shows a fix intensity of 115kt, with some higher values up to about 122kt, so if anything they might be a shade high, but certainly a reasonable and solid initial intensity. The image and graph also highlight the very large RMW and the relatively large extent of the 64kt wind radii.

[euro6208]

For those that don't know yet, JMA uses 10 minute vs JTWC's 1 minute.

[euro6208]

WDPN31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (SURIGAE) WARNING NR 024//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 02W (SURIGAE), LOCATED APPROXIMATELY 308 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED NORTH-NORTHWESTWARD AT 04 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) SHOWS A VERY INTENSE AND HIGHLY SYMMETRICAL SYSTEM THAT HAS
MAINTAINED DEEP CENTRAL DENSE OVERCAST WITH A LARGE AND WELL-DEFINED
37NM EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON THE EYE IN THE MSI LOOP, ADJUSTED FOR SLIGHT TILT AND LINED UP
WITH A MICROWAVE EYE FEATURE IN THE 190524Z ATMS PASS. THE INITIAL
INTENSITY OF 125KTS IS BASED ON A CONSENSUS OF AGENCY DVORAK FINAL-T
ESTIMATES OF T6.0/115KTS (KNES), T6.5/127KTS (PGTW/RJTD) AND THE
OBJECTIVE FINAL-T ESTIMATE OF T6.3/124KTS (ADT), AND REFLECTS THE
SUSTAINED INTENSE CONVECTIVE SIGNATURE OF THE SYSTEM. ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH GOOD RADIAL OUTFLOW, LOW (5-
10KTS) VERTICAL WIND SHEAR (VWS) AND WARM (29-30C) SEA SURFACE
TEMPERATURES (SSTS) IN THE PHILIPPINE SEA. THE CYCLONE IS TRACKING
SLOWLY 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. TY 02W WILL CONTINUE ON ITS NORTH-NORTHWESTWARD TRACK UP TO
TAU 48. AFTERWARD, IT WILL TURN MORE POLEWARD AS IT CRESTS THE STR
AXIS. INCREASING VWS AND DIMINISHING OUTFLOW ALOFT WILL GRADUALLY
WEAKEN THE SYSTEM, DOWN TO 90KTS BY TAU 72. NUMERICAL MODELS ARE IN
GOOD AGREEMENT WITH A GRADUAL AND EVEN CROSS-TRACK SPREAD TO 121NM
BY TAU 48, TIGHTENING TO 78NM BY TAU 72, LENDING FAIR CONFIDENCE IN
THIS PORTION OF THE JTWC FORECAST TRACK WHICH IS LAID CLOSE TO MULTI-
MODEL CONSENSUS.
C. AFTER TAU 72, TY SURIGAE WILL ACCELERATE NORTHEASTWARD ON THE
POLEWARD SIDE OF THE STR. THE ADDITION OF COOLING SSTS WILL WEAKEN
THE SYSTEM FASTER AND BY TAU 120, WILL BE REDUCED TO 55KTS.
CONCURRENTLY AROUND TAU 96, IT WILL UNDERGO EXTRATROPICAL TRANSITION
AS IT ENTERS THE COLD BAROCLINIC ZONE. THE NUMERICAL MODELS REMAIN
FAIRLY TIGHT IN AGREEMENT AND ONLY SPREAD TO 174NM BY TAU 72,
LENDING ALSO FAIR CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC
TRACK FORECAST.//
NNNN

[euro6208]

Becoming better organized.

[rileydoxsee98]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

[euro6208]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

There have been many cases where the eye isn't warm enough and/or cloud tops isn't cold enough but was assessed at 155 knots or higher. You'll be baffled by how low there ADT and Dvorak are.

[Iceresistance]

Becoming better organized.

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

Remember Trami in 2018? It was a CAT 5 when it was stalled!

[rileydoxsee98]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

There have been many cases where the eye isn't warm enough and/or cloud tops isn't cold enough but was assessed at 155 knots or higher. You'll be baffled by how low there ADT and Dvorak are.

Yeah I know. Jebi and Mangkhut are the top examples that comes to mind of non recon storms exceeding their Dvorak imagery. Jebi and Mangkhut if I recall correctly reached their peak intensities at 155-160+knots with W rings, which suggests only a 140knot intensity. You’ve definitely got a good point and your correct however in the case of Surigae the eye wasn’t exactly above and beyond like it was in the case of Jebi. The eye was a little bit supbar for its intensity but maybe im being overly picky on the storm and maybe mesovorts just made the eye look ragged and maybe it really wasn’t. Well anyways. Regardless of that, I don’t know if the winds would’ve had enough time to reach above 155-160knots given the explosive RI and short peak before EWRC began. Plus the outer eye wall could’ve thrown pressure gradient out of whack (see Wilma 2005) during the intensification, which can lead to lower than expected wind speeds for the pressure and structure. Just my 2 cents. I’m sure there’s people in here above my skill level that would disagree and I’m fine with that, and I respect that. I just think that some storms (Halong, Goni peak 2, Surigae peak 1) aren’t as strong as their Dvorak IR suggests.

[rileydoxsee98]

https://twitter.com/200mphcategory5/sta ... 38571?s=21

Anyways, while Surigae looks great now and probably reached a secondary peak of 125-135knots, it has struggled to produce tops colder than -65 and -70C, this is probably due to upwelling, as warm subsurface waters don’t extend as deeply in April. Plus it’s a large system and wasn’t moving very fast, so that doesn’t help either. Overall it did good with what it’s got to work with.

[Meow]

Still a CI7.0-equivalent violent typhoon and expected to sustain its typhoon intensity for 5 days.



<Analysis at 21 JST, 2021/04/19>
Intensity/Category Violent Typhoon
Center Position 14.8N 126.3E
Direction and speed of movement N Slow
Central pressure 915hPa
Maximum wind speed near center 55m/s (105kt)
Maximum wind gust speed 75m/s (150kt)
≥ 50-kt wind area ALL 165km (90NM)
≥ 30-kt wind area ALL 440km (240NM)

[euro6208]

Still a CI7.0-equivalent violent typhoon and expected to sustain its typhoon intensity for 5 days.



<Analysis at 21 JST, 2021/04/19>
Intensity/Category Violent Typhoon
Center Position 14.8N 126.3E
Direction and speed of movement N Slow
Central pressure 915hPa
Maximum wind speed near center 55m/s (105kt)
Maximum wind gust speed 75m/s (150kt)
≥ 50-kt wind area ALL 165km (90NM)
≥ 30-kt wind area ALL 440km (240NM)

That will be hard for people to gasp without any reasoning.

[InfernoFlameCat]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

[euro6208]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

Dorian never reached 165 knots, it only peaked at 160 knots. Highest dvorak for Dorian was only 6.5 = 127 knots. It never reach Cat 5 status according to satellite which is a shame.

But....

[InfernoFlameCat]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

Dorian never reached 165 knots, it only peaked at 160 knots. Highest dvorak for Dorian was only 6.5 = 127 knots. It never reach Cat 5 status according to satellite which is a shame.

My bad did the conversion wrong thought 165knots was 185mph lol. But do you see where I am coming from?

[NXStumpy_Robothing]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

Dorian never reached 165 knots, it only peaked at 160 knots. Highest dvorak for Dorian was only 6.5 = 127 knots. It never reach Cat 5 status according to satellite which is a shame.

But....

For its intensity, Dorian was comparatively shallow in terms of convection; I believe the cloud tops never really topped a uniform temperature of -60 to -65 C, but the eye was something like 25 to 27C. It was odd considering Dorian's known strength and shows the limit of satellite analysis.

[rileydoxsee98]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

Dorian is one of a kind. Only thing that’s like it is, well Irma. But Dorian is even more of one a of a kind. I think Dorian is such an anomaly that it’s one of those rare occasions you can get extreme intensity with cloud tops like that. However I’m not so sure if the tropopause would’ve allowed the cloud tops to be deeper and they if were deeper I’m not sure it would’ve made it any stronger tbh. It’s really a unique case. Anyways the recon for Dorian supports 155-165kts depending on how you interpret it. For me I agree on the 160kts estimate. Anyways in the case of Surigae my argument isn’t against CDO, cloud top, and structure because those things do indeed support the 165kt intensity the JTWC went with (albeit 6 hours too late, but typical JTWC). The issue is that the eye temperature, shape and stability and overall eye integrity doesn’t really support that. Also the microwave imagery was about average and the eye wasn’t as dry as most cyclones that reach 165+knots were. I’m defo not denying the possibility that it was 165+knots as several estimates indicated it could’ve been. But given what we have to go by, I just don’t see much reason to go above 155-160kts with the eye and overall inner core structure. FWIW, a SMAP pass about 3-4 hours prior to the peak recorded 148knots 10 min sustained. That supports an intensity of 155knots. You can go 160kts when factoring in other things and the fact it intensified after the SMAP pass.

[Iceresistance]

So what’s everyone’s estimate for the peak? I’ve seen a lot of people with 165-175kt estimates and while those figures are not impossible I am personally against going this high. Now I totally get that JMA and NHC went with T8.0 (and ADT). However I just don’t feel that it was a true T8.0. Maybe I’m being too picky on it, but to me the eye wasn’t dry enough, warm enough or symmetrical and steady enough to really suggest an intensity above 155-160knots. Coupled with the development of double eye wall during its RI Phase and that’ll hurt the winds. Anyways I feel like T8.0 isn’t that coveted elite Category as it used to be. They seem to be giving them out more easily now, and using SABs CDG roles like half of WPAC 7.5s Will now be 8.0s. Anyways my estimate for the peak of Surigae is 155kts/902mb. This probably seems low to a lot of people in here; but for me there’s not anything that really suggest it was anything above 155-160kts. The same can be said about Goni’s 2nd peak, and Halong at peak. Both of which I believe we’re overestimated.

What would you say about hurricane Dorian? I think an 8.0 rating Justifies incredible wind speeds because if Dorian was 165 knots, which it was with those warm cloud tops, how would Surigae not be 190mph at least. Its also april so there is no low troposphere thing going on either.

My estimate with Surigae's peak is close to the JTWC at 190 mph & 890 MB

The WPAC area is the most tropical of all regions, capable of -100°C Cloud tops, since there are very dangerous storms that can happen & usually there are no Islands with airports where they peak, Recon is usually not possible for the true estimate of the Super Typhoons because the winds could crash them!

Dorian on Dvorak was up to 160 mph, but Recon (Since the storm was VERY CLOSE to Florida) showed the true wind speed of 185 mph & 910 M . . .

[InfernoFlameCat]

The thing about this storm is that when mesovortices are present, they tend to suck out bits of the wall cloud and spin it around the edge of the eye. Thats why Dvorak becomes somewhat unreliable with 150mph + systems along with some other strange things that occur with super TCs. Also Surigae was a compact Cyclone which means it doesn't need to be as impressive as say Hayian to reach 190mph (I know Hayian was 195 but it looked quite a bit better than Surigae) which was a much larger system and needed alot more energy to achieve those kinds of windspeeds. Goni was exceptionally compact as well. The smaller the storm the sharper the pressure gradient and therefore the less power needed to achieve higher windspeeds. This is why I think Surigae achieved 165+knots.