Pyrotornadoes

[MNTornadoGuy]

I found damage photographs and a pyroCb photograph from the 1923 Tokyo fire tornado which might have killed up to 38,000 people.

I have more photos but for some reason they aren't loading.

 

[Juliett Bravo Kilo]

I found damage photographs and a pyroCb photograph from the 1923 Tokyo fire tornado which might have killed up to 38,000 people.

If it really killed that many people an argument could be made that this is the deadliest tornado in world history.

 

[MNTornadoGuy]

If it really killed that many people an argument could be made that this is the deadliest tornado in world history.

A large majority of the people were killed by the fire being "carried" by the tornado so I don't know if it would count as a direct result of the tornado.

 

[MNTornadoGuy]

I found some aerial imagery of the Mammoth Pool EF2 pyrotornado. I haven't mapped the entire path yet but it appears it might have been >460 yards wide at some points.

 

[MNTornadoGuy]

I've done some mapping of aerial imagery of the EF2 Mammoth Pool pyrotornado and it seems to have had a very large damage swath. It seems like it might have been up to ~1000 yards wide.

 

[Juliett Bravo Kilo]

So this is interesting, some pyrotornadoes (or ashnadoes, or ash whirls, not sure what to call them) were spawned from a pyroclastic flow of a volcano:





Also, there is a vortex known as an "ash devil" that often forms in the aftermath of forest fires:



Dust devils, steam devils, snow devils, debris devils, leaf devils or hay devils, water devils, coal devils, ash devils, what's next?

 

[MNTornadoGuy]

On April 8, 1926, a lightning strike would spark a massive fire at an oil-tank near San Luis Obispo CA. The intense heat of the fire generated a pyrocumulus and thousands of whirlwinds. Some of these whirlwinds were true pyrotornadoes, the strongest of these being a killer tornado. This F2+ fire tornado traveled a mile from the fire leveling and sweeping away two cottages, uprooted/snapped fruit trees, tore the roof off of a house, and drove a 2x4 through a pump house. The first cottage was lifted several feet in the air and carried 150 ft while the second cottage was lifted 300 ft into the air and carried 100 ft. Debris was found up to 3 miles away. Two fatalities occurred at the first cottage making it the second deadliest tornado in California history.

 

[MNTornadoGuy]

I've been looking into soundings associated with pyrotornadoes and they appear to be associated with an inverted-V profile, moderate (20-45 kt) 0-6 km shear and turning in the vertical wind profiles or a convergence zone.

 

[MNTornadoGuy]

I've done more research into vegetation damage produced by the 2018 Carr Fire EF3 and it is extremely impressive for the Pacific coast. Unlike in most areas of California, the trees destroyed by the pyrotornado were hardwood, specifically a mix of blue oak, interior live oak, and black oak. These trees were shredded, completely debarked, snapped off halfway up, and uprooted. The damage to shrubbery was also impressive with a century cactus being shredded and other types of shrubs being shredded and possibly partially debarked (though I'm uncertain of this.) Some of these shrubs seem to have been mostly untouched by fire. Everything in the intense core had a reddish tint to it as >1 inch of red clay topsoil was scoured and splattered against almost every surface.

 

[MNTornadoGuy]

On December 31st, 2019 a massive and extremely intense bushfire was rapidly spreading towards the town of Wandella, NSW. Flame heights were likely exceeding 100 ft, fireballs erupted from eucalyptus trees, and a pyrocumulonimbus developed. Eventually, this extreme fire behavior generated a massive and extremely intense fire tornado. This tornado tore through the farming community of Wandella, uprooting or snapped off eucalyptus trees up to 4 ft in diameter and 100 ft tall, tearing metal roofs off of structures and scattering them for hundreds of yards, wrapped corrugated iron around trees, and cars were thrown up to a half-mile and mangled beyond recognition.

 

[buckeye05]

Wow! Impressive vehicle damage there^

By the way, was the East Troublesome, CO event ever confirmed as a tornado? The damage looks to me like there was a strong one, with homes swept away and entire ridgelines deforested.

 

[MNTornadoGuy]

Wow! Impressive vehicle damage there^

By the way, was the East Troublesome, CO event ever confirmed as a tornado? The damage looks to me like there was a strong one, with homes swept away and entire ridgelines deforested.

The homes were destroyed by the fire not by the wind though wind damage might have played a part in the destruction of homes in the area. It doesn't seem like it was ever confirmed by NWS Boulder as a tornado or other event. The damage swath was quite large so it was probably a complex of spinups and straight-line wind damage.

 

[MNTornadoGuy]

I’ve done some extensive research into historical pyrotornadoes and I made a database of potential pyrotornadoes going back to 1871. There seems to have been at least 27 pyrotornadic events since 2000.
PYROTOR Database

 

[Juliett Bravo Kilo]

I’ve done some extensive research into historical pyrotornadoes and I made a database of potential pyrotornadoes going back to 1871. There seems to have been at least 27 pyrotornadic events since 2000.
PYROTOR Database

Based on your database, I'm beginning to think that pyrotornadoes are way more common than previously thought, and might (at certain times of the year and certain areas of the country) be as common as regular tornadoes. Pyrometeorology (or whatever you wish to call it) is likely going to be an emerging and growing fields in the coming decades.

 

[MNTornadoGuy]

Based on your database, I'm beginning to think that pyrotornadoes are way more common than previously thought, and might (at certain times of the year and certain areas of the country) be as common as regular tornadoes. Pyrometeorology (or whatever you wish to call it) is likely going to be an emerging and growing fields in the coming decades.

They likely are a lot more common than previously thought. There are many pyroCb/Cu producing fires in the Alaskan, Siberian and Canadian wilderness that likely generate pyrotornadoes.

 

[MNTornadoGuy]

For example here are some PyroCbs from fires in northwestern Canada on 8/4/1998. The tallest of these PyroCbs had tops of 52,490 ft.


Here is a pyroCb in Russia with an overshooting top from 8/15/2017.

 

[MNTornadoGuy]

It appears it might be possible to forecast the potential for pyrotornado development. The strongest pyrotornadoes seem to form in an environment with an inverted-V profile, a Haines Index of over 4, high DCAPE values, steep 0-3 km lapse rates, and high values of 10-meter absolute vorticity. I made an experimental index called the Pyrotornado Index or PTI which uses this formula: ((Haines Index+0-3 km Lapse Rates+DCAPE)/1000)+10-m Absolute Vorticity (1E-5 s-1.) The Carr Fire had a value of 20.41, the Creek Fire had a value of 13.3 while the Loyalton Fire had a value of 11.29.

 

[MNTornadoGuy]

The 2003 Canberra pyro-tornado has been the source of numerous rumors that over-exaggerated its intensity. It produced no EF3 damage and the strongest damage it produced was EF2 in intensity. Vehicles were not mangled and no trees were debarked. It even appears to have been a family of 4 separate tornadoes instead of one long-tracked tornado.

 

[MNTornadoGuy]

The Creek Fire was definitely one of the most intense pyroconvective events in the post-2000 era. The pyrocumulonimbus had all the characteristics that a supercell would. It had an inflow notch, hook echo, BWER, mesocyclone, and even a flying eagle-like formation. The mesocyclone lasted for 8 hours. At points, it had tops of 50,000 ft comparable to supercells on the plains.

 

[MNTornadoGuy]

Fire weather researcher Neil Lareau did an interesting presentation about radar analysis of pyrotornadoes. They talk about the pyrotornadoes at 1:45:40