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It's tornado time, so keep an eye on the sky
Outdoors Columnist Last week I wrote about tornadoes and the Fujita Scale, introduced in 1971 by Dr. T. Theodore Fujita to categorize tornados by intensity and area and to estimate wind speeds. Shortcomings led to the 1992 updating that became known as the Modified Fujita Scale.
More refinements led to the newest measuring device, the Enhanced Fujita Scale, which was implemented for usage on Feb. 1.
The new scale supports and maintains the original tornado database. Additional factors the committee wanted to address and incorporate included consistent assessment of damage, enhanced description of damage with examples and photos that include not only structures but also vegetation, base damage assignment on more than one structure if available, develop a PC-based expert system, develop training materials, data collection, maintain current tornado database, surveys should include additional data, mean and maximum damage path width, basis for damage assignment, latitude/longitude of where the path began and ended, number of hours spent on the damage survey, names of survey team member(s).
Last year 22 tornadoes occurred in Minnesota from May 7 through Sept. 16, 2007. There seems to be a little discrepancy in the information, because one source listed 21 tornadoes and did not include the Sept. 16 tornado in Rogers. A young girl died in that incident. The Aug. 24 tornado in Nicollet and LeSueur counties, rated as F-3, had a path length of 33 miles. Thirty-seven people were injured and one person perished. Eighteen of the tornadoes were rated at F-0 or F-1, three designated as F-3. The Rogers tornado was classified as an F-2.
According to Paul Douglas, WCCO meteorologist, on June 8, 2007, a tornado struck near the small town of Elizabeth, about seven miles northwest of Fergus Falls in western Minnesota. The tornado, traveling northeast, skipped through the area around 2 p.m. and then touched down again north of Pelican Rapids. Damaging funnels were also reported around Crystal Lake and Lake Lida. All sightings were in Otter Tail County.
Weather service warning coordinator Greg Gust said two meteorologists have taken a look at the storm's path. Gust said the tornado was an F-1 at that point with winds of up to 95 miles an hour. The storm cell then strengthened to F-2 as it came across Lake Lida. Funnel clouds were also spotted in central Wilkin County on that same day, but no damage was reported.
This week a tornado appeared north of Bemidji. Clearly it's tornado time.
ANDREA LEE LAMBRECHT, naturalist and outdoors photographer, may be reached at andreal@umn.edu.
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Overcast, 61°
