Hurricane Force on the Great Plains | Prairie Public Broadcasting

Hurricane Force on the Great Plains

Aug 8, 2019

August in North Dakota is often a time for rain. The hot and humid conditions can create severe weather conditions, such as raging thunderstorms or tornados. But apart from these well known weather hazards, those conditions can also create downbursts. Unlike tornados, whose winds spiral, downbursts shoot straight down, then rocket off in every direction. The resulting winds can be well over 100 miles per hour and are highly destructive, especially on the plains where there is little to resist them. On this date in 2001, the area around Walsh and Grand Forks counties experienced one such downburst.

It had already been storming. Just 24 hours before, Hillsboro had been experiencing winds up to 110 mph. As the weather continued to develop, the area of Walsh and Grand Forks counties got caught under clashing winds, creating violent convection currents with tornadoes, and hail up to an inch-and-a-half in diameter. The cloud-top temperature was as cold as 90 below zero.

The downburst struck a bit after 8pm. The Grand Forks Air Force Base recorded winds of 114 miles per hour.  8 miles to the south, the Grand Forks National Weather Service recorded winds at 101 miles per hour. By the time the downburst hit Crookston, Minnesota, at 8:56, the wind had dropped a bit, but was still recorded at municipal field at 79 miles per hour.  That still ranked a 12 on the Beaufort Windforce Scale – the highest possible ranking called “hurricane force.”

An employee at the weather service said everyone was unsure if the roof would hold, and quite luckily, it did.  Pictures of the aftermath show trees split apart, with large branches strewn about. One records a black sedan crushed under a tree trunk, and another shows the front of a warehouse completely ripped off. Luckily, the storm only brought property damage and no people died. However, as heat and humidity increase in North Dakota, more of these downbursts could blow in soon.

Dakota Datebook written by Lucid Thomas

Sources:

https://en.wikipedia.org/wiki/Downburst

https://en.wikipedia.org/wiki/Climate_of_North_Dakota#Seasons

https://stormtrack.org/community/threads/what-does-nwsfos-do-when-in-the-path-of-severe-storms-tornado.9597/

https://cimss.ssec.wisc.edu/goes/misc/010808/010808.html

https://en.wikipedia.org/wiki/Beaufort_scale

https://files.dnr.state.mn.us/natural_resources/climate/summaries_and_publications/fargo_climate.pdf