By Harold Reutter
The National Weather Service in Nebraska does not have statistics to either refute or buttress a theory by Ted Fujita that southern Nebraska may be at increased risk for severe tornadoes.
Dave Theophilus, Nebraska area manager for the National Weather Service, said he has ''no data either way'' on Fujita's theory.
Theophilus noted Fujita does have an excellent reputation regarding his research into tornadoes.
Fujita's research on storm severity looks at national patterns, while the National Weather in Nebraska tends to look more at statistics for the state, he said. Those types of statistics would not reveal any pattern in where severe storms strike.
The National Weather Service in Nebraska does have statistics on the number of fatalities in Nebraska by decade and those numbers show that 1940-49 with 22 deaths and 1950-59 with 28 deaths were two of the worst on record.
On the surface, those numbers might tend to back up Fujita's claim of a 40-year cycle in severe storms.
However, Theophilus said factors other than storm severity may be at work in the reduced number of tornado deaths in recent years.
''A lot of things have changed in our ability'' to forecast tornadoes and issue warnings to the public since the 1940s and 1950s, he said.
Theophilus said he would like to think the improved warning system has something to do with the reduction in the number of deaths since the 1950s.
Fujita's theory deals only with the intensity of storms, not with the total number of storms.
However, Theophilus said the nation is running well ahead of last year's record pace for the number of tornadoes. ''We're 200 ahead of last year,'' he said.
He said the explanation for the number of storms is simple.
''We have warm, moist air parked over the Midwest'' while an upper level low pressure system associated with the jet stream has been to the west of Nebraska, Theophilus said.
''When that pattern doesn't change for a month, you have a large number of tornadoes,'' he said.
Typically, the jet stream moves from south to north each spring, Theophilus said. That's why May and June are busy months for tornadoes in Nebraska, while the number of tornadoes in the state usually declines later in the summer as the jet stream moves farther north.