1990 is fast becoming one of the worst years on record for tornadoes and flooding across the middle and southern sections of the nation. So far this year, 726 tornadoes have touched down nationwide, well ahead of the 640 tornadoes recorded during the first six months of last year, and the 30-year average of 482 tornadoes recorded between January and July, said Frederick Ostby of the National Severe Storms Forecast Center here. The nation had 747 tornadoes in the first six months of 1973 _ one of the biggest years for tornadoes since 1950, when the forecast center began keeping reliable records of the storms. There were 756 tornadoes reported in 1982. ``We seem to be on a pace that would put us up with those two years,'' Ostby said. The culprit in this tornado barrage across the Plains is a persistent West Coast pattern of low pressure in the upper atmosphere that is keeping the jet stream anchored at a southern latitude. This year's storms seem particularly violent, as illustrated by the March 13 tornado that cut a swath a mile wide and brought winds of 300 mph to a field in Kansas. The tornado was the strongest to hit the United States since 1985. The first weekend in June saw the worst outburst of tornadoes since 1974. Ostby said 101 tornadoes touched down from Kansas to Kentucky, leaving nine people dead. But a break in the storm pattern may be at hand. As summer wears on, the land warms up and cold air from Canada retreats. This moves the boundary of the jet stream to the north, Ostby said. ``Our longer range computer forecasts are suggestive of that. There is some kind of a readjustment beginning to take place in the upper atmosphere,'' he said. However, a study of tornado trends indicates parts of the Midwest, particularly Kansas and Missouri, are heading into a six-year period of more intense tornadoes. The study of tornadoes since early this century shows that they are concentrated in regions for five- or six-year periods, said Michael Smith, president of WeatherData Inc. But warning of impending storms is becoming more sophisticated, leading to fewer deaths. Tornadoes have caused 20 deaths this year, while an average year in the 1980s saw 52 deaths, and in the 1970s nearly 100, Ostby said. ``There are better watches, better warnings and a better response,'' Ostby said. Ostby credited the quicker response to computers that allow meteorologists to see many sources of data, such as satellite readings, more clearly. Flooding in the South and the Plains has been as destructive as the tornadoes. The death toll from last week's flash floods in Shadyside, Ohio, rose to 21 on Monday, making the flood one of the most deadly in recent years. Authorities held out little hope for more than a dozen others listed as missing. Wegee and Pipe creeks overflowed during storms that dumped 5{ inches of rain in 3{ hours. The floods destroyed as many as 70 houses and damaged up to 40, officials said. Flooding in Texas has been blamed for at least 16 deaths since April. An estimated 10,000 people were forced from their homes, and high water caused hundreds of millions of dollars in damage.
2017 is fast becoming one of the worst years on record for tornadoes and flooding across the middle and southern sections of the country . One tornado in Kansas was the strongest since 1985 . Flooding in the South and the Plains has been as destructive as the tornadoes . Studies of tornadoes indicate they are concentrated in regions for five or six months olds . regions of the Midwest , particularly Kansas and southwest , seem to be entering such a trend . However , because computers allow meteorologists to see more sources of tornadoes more clearly , prediction of impending storms is becoming more sophisticated leading to fewer deaths .