The Yellowstone National Park F-4 Tornado

[Hannah.Taylor]

I'm surprised that no one here has posted this.

On July 21, 1987 a tornado touched down 45 miles northeast of Jackson, WY. The tornado crossed large elevation gradients and crossed the Continental Divide at well over 10,000 feet! To date this is the highest elevation a violent tornado (F-4/F-5) has ever been recorded.

Dr. Fujita found that a total of 72 microbursts accompanied this tornado. Miraculously there were no injuries or fatalities.

Teton Wilderness, WY F4 Tornado – July 21, 1987 – Tornado Talk

www.tornadotalk.com

 

[Boris Konon]

I'm surprised that no one here has posted this.

On July 21, 1987 a tornado touched down 45 miles northeast of Jackson, WY. The tornado crossed large elevation gradients and crossed the Continental Divide at well over 10,000 feet! To date this is the highest elevation a violent tornado (F-4/F-5) has ever been recorded.

Dr. Fujita found that a total of 72 microbursts accompanied this tornado. Miraculously there were no injuries or fatalities.

Teton Wilderness, WY F4 Tornado – July 21, 1987 – Tornado Talk

www.tornadotalk.com

This tornado was 2.5 mi wide at one point, making it tied w/ the widest tornado on record up to this time.

For reference, here are all tornadoes w/ at least 2 mi width at some point. Some of this data is from the Tornado Project and not listed in NCEI's Storm Data.

Mulhall OK (unofficial) 5/03/1999 4.3 mi
El Reno OK 5/31/2013 2.6 mi
Hallam NE 5/22/2004 2.5 mi
Teton Wilderness WY 7/21/1987 2.5 mi
Tatum SC 3/28/1984 2.5 mi
Bassfield MS 4/12/2020 2.3 mi
Trousdale KS 5/04/2007 2.2 mi
Moshannon State Forest PA 5/31/1985 2.2 mi
Pardeeville WI 6/07/2008 2.0 mi
Gruver TX 6/09/1971 2.0 mi
Amite LA 4/24/1908 2.0 mi
Reserve KS 5/17/1896 2.0 mi

I've noticed sometimes tornadoes are listed as "average path width" for the entire track, others "max width." It is subjective and hard to determine often where tornadic winds begin and end, esp. when wrapped in an intense RFD, as RFD winds can easily exceed 100 mph.

 

[Hannah.Taylor]

This tornado was 2.5 mi wide at one point, making it tied w/ the widest tornado on record up to this time.

For reference, here are all tornadoes w/ at least 2 mi width at some point. Some of this data is from the Tornado Project and not listed in NCEI's Storm Data.

Mulhall OK (unofficial) 5/03/1999 4.3 mi
El Reno OK 5/31/2013 2.6 mi
Hallam NE 5/22/2004 2.5 mi
Teton Wilderness WY 7/21/1987 2.5 mi
Tatum SC 3/28/1984 2.5 mi
Bassfield MS 4/12/2020 2.3 mi
Trousdale KS 5/04/2007 2.2 mi
Moshannon State Forest PA 5/31/1985 2.2 mi
Pardeeville WI 6/07/2008 2.0 mi
Gruver TX 6/09/1971 2.0 mi
Amite LA 4/24/1908 2.0 mi
Reserve KS 5/17/1896 2.0 mi

I've noticed sometimes tornadoes are listed as "average path width" for the entire track, others "max width." It is subjective and hard to determine often where tornadic winds begin and end, esp. when wrapped in an intense RFD, as RFD winds can easily exceed 100 mph.

Where do you see it was 2.5 miles wide?

In the link I provided it says 2,550 yards. A yard = 3 ft. That would be 7,650 ft, divided by 5,280 ft = 1.4488 miles wide.