Windsor tornado was atypical

By Todd Hartman, Rocky Mountain News (Contact)

Published June 10, 2008 at 5:59 p.m.
Updated June 10, 2008 at 5:59 p.m.

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Ted Ullmann / Special To The Rocky/Courtesy Cbs4 News

Ted Ullmann, of Greeley, took this photo a mile east of Windsor on Colorado 392. He was about a mile north of the tornado as it moved west on Eastman Park Boulevard.

Winds up to 150 miles per hour, a storm track covering 34 miles and a mile-wide path of wreckage.

Those are the numbers behind the powerful and unusual tornado that tore through Windsor last month.

A new report from the National Weather Service documents the severity of the storm, which marched relentlessly from southern Weld County, near Platteville, to seven miles east and north of Fort Collins.

NWS scientists believe wind speeds ranged from 130 to 150 miles per hour, making it an EF3 on the Enhanced Fujita Scale that ranks tornadoes from an EF0 to EF5 — one with winds are clocked at over 200 mph.

Twenty F3s have been recorded in Colorado since 1950. And, more tornadoes are reported in Weld County than in any other county in Colorado. But they are usually weak. The last recorded F3 in Weld County came May 15, 1952, and injured five.

"Virtually all, or most tornadoes in Weld County are...F0 or F1," said Bob Glancy, a meteorologist at the weather service's Boulder office who put together the report. "This one, not only was it on the ground for a long period of time, it was also quite powerful."

Its mile-long width and 34-mile track also were remarkable.

"Most tornadoes in this part of the state would generally have tracks of a mile or less; most would have associated wind speeds 110 miles an hour or less — those are two things that stand out the most," Glancy said.

The Windsor Tornado was spawned when a cold weather system more typical of March collided with warmer, wet air from the Gulf of Mexico, providing energy for the storm. Strong winds from the south helped the tornado move so fast across the landscape.

Typically, the "richer, more unstable moisture" that helps fuel such storms lies further east, which is why stronger tornadoes don't often visit the Front Range or even the developed region east along I-25, Glancy said.

"In the Midwest, conditions conducive to larger storms are more prevalent ... because of deeper, low-level moisture, and more wind issues," he said.

A final note on the storm: Its northwesterly track was "very unusual" the report said, as it's far more typical in Colorado for tornadoes to move to the northeast, east or southeast.

• June 10, 2008

  10:33 p.m.

  Suggest removal

  spd writes:

  hmm...must be global warming!

  :p

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