Dreamers & Twisters

An isolated tornado or two is expected to occur from 4 to 7 o'clock p.m. in an area 60 miles north and south of Salina, Kans., running northeast to a line 40 miles north and 30 miles south of Kirksville, Mo.

--Typical U.S. Weather Bureau forecast

As the spring tornado season swirled into full blast on the Great Plains last week, such ominous warnings crackled constantly on TV and radio. And it was the proud boast of Meteorologist Donald C. House, head of the Weather Bureau's Severe Local Storm Center at Kansas City, that 55% of the bulletins were right on the button. Another 30% were near misses. Residents of "Tornado Alley" (the south central U.S.) were seldom surprised by unexpected twisters.

Despite the remarkable accuracy of its forecasts, the Weather Bureau is still not sure just why tornadoes occur. They strike out of thunderclouds that form when the temperature of the upper air drops some 3DEG every 300 ft. of altitude. But they appear in some thunderclouds and not in others where conditions seem the same.

In its stubborn search for an explanation, the bureau keeps a dozen airplanes on duty. Last week its weather squadron was near Oklahoma City, right in Tornado Alley, and whenever thunder threatened, a highflying, camera-laden U2* soared far above the thunderheads. Supersonic jets, laden with instruments, darted through the fringe of the clouds. Even far from the core they bounced suddenly from 75 m.p.h. updrafts to downdrafts moving just as fast. At the center of a storm, winds of 350 m.p.h. were not uncommon.

The pilots who handle these hardy planes are called "rough riders." Says Rough Rider Air Force Major John J. Knight, an F106 pilot: "Every time I approach a storm I wonder how rough this one is going to be. You know it is going to be rough, but you don't know how rough. And once you're inside you're so busy you can't think of anything else. You don't horse the controls around. You have to believe your instruments. In those things you can't fly by the seat of your pants, because the seat of your pants doesn't even know where it is."

When the rough riders have flown for a few more years, Weather Bureau experts believe that meteorologists will be able to pick with certainty the specific thunderclouds that will spawn twisters. Next step will be to exercise a sort of birth control over the violent storms, which last year killed 49 people in the U.S. and did at least $50 million worth of damage. No one knows yet how this control can be accomplished, but Bureau Meteorologist Clayton Van Thullenar says: "If we were not dreamers to some extent, we wouldn't be doing this."

* No longer flying over Soviet Russia, the famed U2s go quietly about their weather research at bases reaching from Alaska to Australia. Part of their time is presumably spent collecting data from Caribbean storms.

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