Biggest underperformers and overperformers

[al78]

I think we can add Philippe to the list of underachievers.

[NotSparta]

I think we can add Philippe to the list of underachievers.

The storm, that is

[ljmac75]

One overperformer would be Hurricane Epsilon of 2005. From being expected to dissipate in a few days to becoming the longest-lived December hurricane on record, very impressive. Zeta in 2005 is in a slightly similar camp. And Zeta in 2020.

What counts as an underperformer depends on whether you want to consider the storm's whole history or just a portion of it. Hurricane Gustav in 2008 strengthened to near category 5 status before striking Cuba, overperforming. But, after emerging into the Gulf of Mexico, it steadily weakened the whole way on its path to landfall rather than steadily strengthening. I really can't think of any really significant storm that underperformed the whole way through.

[tolakram]

Lee is 100% an underperformer---no doubt about it. HAFS models expected it intensify to 170-180 knots, yet it only reached a measly 145 knots.

"Only" 145 kts. I feel you put your expectations way too high. You got a Cat 5 and you're still complaining.

It might have been sarcasm.

[xtyphooncyclonex]

Koinu is a prime example of a multiple time overachiever. Expected to weaken to a cat 2 approach to Taiwan, ended up as a 120-kt cat 4 right before landfall. Supposedly rapidly getting shredded to a TS at the SCS after Taiwan and a surge of shear, instead shot up to a Cat 3 (and maintained strength).

[Teban54]

Philippe joins the list as the latest underperformer. Although spending 2 weeks without getting stronger than 45 kts is quite an "achievement" in itself.

[doomhaMwx]

STY Zeb (1998) was a huge overperformer.
I looked at archived JTWC warnings for Zeb and found that early forecasts only had a category 1 TY hitting Luzon. Notably, operational estimate on 10/12 18Z was 100kt and called for a 120kt peak, but the next warning (10/13 00Z) came out at 150kt! Zeb hit land on the 14th at 155kt.

[HurricaneRyan]

Overperformers:
Alex 2004 and 2010
Ophelia 2011 and 2017
Dennis, Emily, Katrina, Rita and Wilma
Patricia

[aspen]

Overperformers:
Alex 2004 and 2010
Ophelia 2011 and 2017
Dennis, Emily, Katrina, Rita and Wilma
Patricia

I’d say this year’s Ophelia was also a bit of an over-performer, because I certainly wasn’t expecting it to become a borderline hurricane ahead of landfall.

[DorkyMcDorkface]

Initial advisory had a 40kt peak...

[ElectricStorm]

Initial advisory had a 40kt peak...
https://i.postimg.cc/R0zHGZYw/goes16-vis-18-E.gif
https://i.ibb.co/rk0y6mG/recon-AF307-0118-E-OTIS.png

Interesting how the 2017 version of Otis also wasn't expected to do much initially but ended up becoming a major...

[Astromanía]

Never underestimate the EPAC in october when we have el Niño

[Category5Kaiju]

Is it just me, or have many of the (especially) recent EPAC storms been grossly underestimated regarding their peak strengths?

[Hurricane2022]

Is it just me, or have many of the (especially) recent EPAC storms been grossly underestimated regarding their peak strengths?

I agree with you. It is likely that the hurricanes Douglas '20, Felicia '21, Darby '22, and especially Dora and Jova this year, had their peaks underestimated by about 10 - 25 mph. I believe Felicia and Dora were 2 Category 5 hurricanes that the satellite estimates hid, while Darby and Douglas were 2 high-end C4 hurricanes. Jova likely had winds in excess of 175 mph, so we will also wait for the NHC's final verdict and see whether or not they update Jova's peak.

Also the WPAC was not mentioned in this conversation, but I make a point of mentioning some typhoons that were underestimated by the JTWC after 2020, such as Hinnamnor and Nanmadol last year, and Saola this year. Although Hinnamnor was indeed officially a C5, I think its first peak wind strength was probably around 150 - 155 kt, not 140 kt.
Nanmadol and Saola probably had peak intensity around 140 and 145 kt, respectively. Officially, both were classified as Category 4 Super Typhoons, with estimated winds of 135 kt.

In the Atlantic, I think that Sam '21 may also have been a C5 for a brief period, while this year Jose and Ophelia may both have been Category 1 hurricanes.

[aspen]

Add Otis to the list of over-performers. Even just 24 hours ago, I don’t think a single model — not even the HWRF/HAFS — forecast a major hurricane peak, let alone a high end 4. The level of RI we’ve seen has rivaled Wilma (10 mb drop in under 1.5 hr) and Patricia (+80 mph in 12 hours). I’ve never seen a system with such bearish forecasts pull a complete 180 and rival some of the fastest intensifying systems in the Western Hemisphere. 2017’s Otis similarly became a major out of nowhere, but this has been something else.

[MarioProtVI]

Add Otis to the list of over-performers. Even just 24 hours ago, I don’t think a single model — not even the HWRF/HAFS — forecast a major hurricane peak, let alone a high end 4. The level of RI we’ve seen has rivaled Wilma (10 mb drop in under 1.5 hr) and Patricia (+80 mph in 12 hours). I’ve never seen a system with such bearish forecasts pull a complete 180 and rival some of the fastest intensifying systems in the Western Hemisphere. 2017’s Otis similarly became a major out of nowhere, but this has been something else.

And now it is a Cat 5. I think it pretty single handedly topped the list here to the point anything more is kinda useless…

[zhukm29]

2017's Otis was both an underachiever and an overachiever - it was only named on its 21st advisory after staying as a depression for 20 advisories straight despite expectations that it would become a TS much earlier. Then, once it got its name, it proceeded to strengthen into a major that no one expected. Seems like Otis exists just to defy the models and forecasts! But this will likely be the last Otis we see. This was Otis 2017's last advisory as a TD (it was named on the next advisory and the rest was history):

[Teban54]

24 hours ago:

FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 13.6N 97.9W 45 KT 50 MPH
12H 24/1200Z 14.4N 98.3W 50 KT 60 MPH
24H 25/0000Z 15.5N 98.9W 55 KT 65 MPH
36H 25/1200Z 16.4N 99.5W 60 KT 70 MPH
48H 26/0000Z 17.3N 100.3W 50 KT 60 MPH...INLAND
60H 26/1200Z 18.0N 101.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 27/0000Z...DISSIPATED

Now:

INIT 25/0300Z 16.1N 99.7W 140 KT 160 MPH

Otis has explosively intensified 95 kt during the past 24 hours, a mark only exceeded in modern times by Patricia in 2015.

[Category5Kaiju]

I think we should rename the title of thread as the "overperformer" has a clear winner.

[WeatherBoy2000]

I don't think a storm can overachieve much more than this. Unfortunately a model screw up with devastating consequences.