Dust Storms in the Great Plains

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  • Months of searing heat and drought conditions have contributed to loose topsoil, favourable conditions for sediment entrainment in strong winds. Photo: Gareth Fuller/Press Association Images.

    Image from the MODIS instrument on NASA's Aqua satellite showing the extent of Thursday's dust storm.

    Wildfires have already affected Nebraska and South Dakota this year, as can be seen from the MODIS instrument on NASA's Terra satellite on 22nd July.

  • Dust Storms in the Great Plains
    20.10.2012 13:45

     

    Strong winds, due to an autumnal storm, wreaked havoc across parts of the Great Plains of the USA on Thursday, with dust storms, power outages and interstate pile-ups amongst numerous disruptions.


    A low pressure system formed over southern parts of the Canadian province of Manitoba on Tuesday and moved south-east across Minnesota on Wednesday. By Thursday, the depression was centred across the Midwest region, leading to disruptive gale force north-westerly winds over the Great Plains and gusts of around 50-70mph across the Dakotas and Nebraska. Among the highest gusts recorded were 70mph at Ord, Nebraska and 71mph at Winner Regional Airport in South Dakota. The winds caused trees to topple in the city of Columbus and parts of the downtown area lost power. There were also power outages to 725 customers in the nearby city of Norfolk.

    Meanwhile, a combination of an extended drought and the action of farmers ploughing their fields ready for winter planting has led to soil being loosened in recent weeks. The strong winds associated with the low pressure readily picked up the sediment on Thursday, causing dust storms spanning hundreds of miles laterally and several thousand feet vertically in the atmosphere. The satellite image to the left of this article, courtesy of NASA, indicates how the origin of the main dust storm appeared to originate from southern Nebraska, with other localised sources in Kansas and Oklahoma.

    Dust kicked up by the winds caused near-blackout conditions due to the trapping of sunlight, leading to severe hazards on transport routes. Poor visibility conditions caused vehicle collisions on Interstates 35 and 80 and the closure of a 45 mile stretch of road. High winds were also blamed for the spreading of wildfires across Nebraska, with 16,000 acres of land burned in Cherry County alone, although they have now been all but extinguished, helped by calmer winds.

    The dust storms were an unwelcome reminder of the Dust Bowl, a period of severe drought in the 1930s which led to extensive “black blizzards” and “black rollers”, as they came to be dubbed across the Great Plains. Millions of acres of farmland were destroyed and thousands of people were displaced through the course of the decade.

     

    By: Nick Prebble