Top Tornado Wind Speed (in Theory)?

[Steve Holmes]

The A/V films I saw in school said 500 mph, but I've never heard of a DOW estimate of more than 318 mph (Greenfield). So, under perfect conditions, how fast can they go?

 

[Jamie H]

I've seen a few sites say 300-400mph is the limit, based on stidues, but none of them linked to the studies!

 

[Mike Smith]

There was a photogrammetry study of the Dallas tornado of April 1957 where they said they "measured" winds of more than 318 mph. Please see: The tornadoes at Dallas, Tex., April 2, 1957 in SearchWorks catalog

 

[Randy Zipser]

In my master's thesis from 1976, I made the statement: "[In] Hoecker's (1960a) analysis of the Dallas tornado of 2 April 1957...the maximum tangential speed [76 m/sec (170mph)] and upward speed [67 m/sec (150mph)] were derived directly by tracking debris, dust particles, and cloud tags in scaled movies of that tornado, similar to the procedures used in the study reported here." Those velocity figures were taken directly from a published, peer-reviewed paper in the Monthly Weather Review, Vol. 88, pp. 167-180, titled "Wind Speed and Air Flow Patterns in the Dallas Tornado of April 2, 1957."

The statement from the source you reference above is incorrect. It appears to confuse Hoecker's correct information from the MWR with the results of Josh Wurman's Doppler On Wheels (DOW) recorded a "record high" measurement of 295mph as the strongest, most destructive F5 tornado in Oklahoma history up to that time was passing through the Bridge Creek area on its way to Moore, OK, on May 3, 1999. The significance of the "318mph" wind speed reference is due to the fact that in 1999, an F5 tornado had a wind speed estimate range of 261-318mph on the Fujita Tornado Intensity Scale (F-Scale). In several subsequent publications that I have read, the F5 range maximum estimate has been often cited in reference to this tornado rather than the actual Doppler recorded measurement (23mph lower, but certainly within a reasonable range of measurement "error"). I hope this clarification helps.

 

[William Monfredo]

A cop pulls a driver over and says, "Do you know how fast you were going? I'll tell you...sixty miles-per-hour, that's how fast."
The motorist says to the policeman, "Oh yeh, but I wasn't planning on being out that long!"
That joke sort of relates to the fact that we typically look at the quickest quarter-mile and fastest three-second gust.
But on time and space scales where distances & times are way less than I've just mentioned, the speeds arguably go higher.

 

[Randy Zipser]

In my master's thesis from 1976, I made the statement: "[In] Hoecker's (1960a) analysis of the Dallas tornado of 2 April 1957...the maximum tangential speed [76 m/sec (170mph)] and upward speed [67 m/sec (150mph)] were derived directly by tracking debris, dust particles, and cloud tags in scaled movies of that tornado, similar to the procedures used in the study reported here." Those velocity figures were taken directly from a published, peer-reviewed paper in the Monthly Weather Review, Vol. 88, pp. 167-180, titled "Wind Speed and Air Flow Patterns in the Dallas Tornado of April 2, 1957."

The statement from the source you reference above is incorrect. It appears to confuse Hoecker's correct information from the MWR with the results of Josh Wurman's Doppler On Wheels (DOW) recording of a "record high" measurement of 295mph as the strongest, most destructive F5 tornado in Oklahoma history up to that time was passing through the Bridge Creek area on its way to Moore, OK, on May 3, 1999. The significance of the "318mph" wind speed reference is due to the fact that in 1999, an F5 tornado had a wind speed estimate range of 261-318mph on the Fujita Tornado Intensity Scale (F-Scale). In several subsequent publications that I have read, the F5 range maximum estimate has been often cited in reference to this tornado rather than the actual Doppler recorded measurement (23mph lower, but certainly within a reasonable range of measurement "error"). I hope this clarification helps.

One other thing I forgot to mention in the post above was recalling reading about a similar maximum Doppler wind speed in the El Reno, OK, tornado on May 31, 2013 (the same tornado that took the lives of the TWISTEX team: Tim and Paul Samaras and Carl Young). Even though that tornado was rated an EF3 and had a maximum width of over 2.5 miles (over open country), two DOW vehicles were sampling, and both DOWs measured wind speeds over 200mph, with one recording winds of at least 295mph near the surface in a satellite-vortex within the larger tornado circulation.

Since the Joplin, MO, EF5 tornado on May 22, 2011, which Mike Smith described as "as bad as it gets," was not sampled by mobile DOWs, we will never know what the maximum wind speeds were near the ground when Joplin was struck, but we can surmise that similar wind speeds to the OK events above were likely, based upon structural damage observed.