Doha - Severe storms have been battering the US Great Plains for more than two days, creating several tornadoes with large hail and damaging winds.As many as six buildings were damaged in Bristow, Oklahoma after high winds and grapefruit-sized hail swept through the Creek Country city which has a population of 4 200.The tornado left a path of destruction and survey teams assigned an EF1 rating to the storm - this means that its winds were estimated between 160 to 180km/h.The storm damaged power lines, homes and uprooted trees. At one point, the National Weather Service referred to the twister as a "catastrophic tornado".One person drowned in central Oklahoma when their car was swept off the road. Two other people were critically injured after a tornado touched down near Dodge City, Kansas. At least 26 tornadoes have been reported from Colorado to Michigan central and eastern Wyoming, and as far north as Michigan's Upper Peninsula.Further rounds of severe thunderstorms are expected across the Plains and the Midwest. Warm, moist, southerly winds continue to be drawn up from the Gulf of Mexico around a large area of high pressure. The feature is known as a "blocking high" because it is preventing the eastward clearance of the storms. Temperatures will approach 30°C across the eastern half of the country.The storms will continue into the weekend. The greatest risk for tornados will be across the appropriately named 'Tornado Alley' with twisters most likely across Nebraska, Kansas and Oklahoma.