Severe thunderstorms hit US Midwest
A line of severe thunderstorms moved through Midwest USA on Friday night, spawning at least one tornado and hail stones the size of golf balls. The storm generated winds of around 80mph (129kph), cutting the power to over 1000 residents in the area. The same storm system delivered snow further north, in Minnesota and the Dakotas.
A thunderstorm can be described as being ‘severe’ when one or more of a number of criteria is met. The winds gusts have to reach or exceed 57.5mph (92kph), hail greater than 19.1mm (0.75 inches) in diameter is produced or tornadoes have to be generated. This particular storm system fulfilled all three of the necessary criteria needed to class it as ‘severe’.
Over the weekend storms are forecast to develop further south from Texas to the Great Lakes. According to the National Severe Weather Centre, the thunderstorms will continue to be fuelled as cold air from the storm clashes with warmer air flowing out of the Gulf of Mexico. The strongest storms are expected to produce damaging winds and torrential downpours across the Mississippi Valley.
