This year has been remarkably quiet in Tornado Alley.

Oklahoma went until the beginning of May to log its first tornado, the latest in the season. Remarkably, Oklahoma City has yet to be placed on a tornado watch. In an average year, Oklahoma City would have already been issued five or six tornado watches by early June. A typical tornado watch persists for an afternoon or evening.

The National Weather Service issues a tornado watch when the conditions are right for tornadoes to develop. A warning is issued when a tornado is on the ground. Oddly, Massachusetts and Vermont have been under tornado watches this year, beating out the state notorious for its vicious twisters.

It comes as no surprise that 2018 is shaping up to be one of the slowest tornado years in recent memory. Just over 330 have been counted so far, down from the nearly 600 that would normally have occurred by this time of year.

Like clockwork, the Great Plains see scores of twisters sweep across the springtime prairie. A thousand tornadoes may touch down in the United States in a given year, about half of them in Tornado Alley.

On May 1, several tornadoes spawned in Kansas and northern Oklahoma along and west of I-35. Most have been relatively weak, with the 17 in Oklahoma in May causing little in the way of damage.

WASHINGTON POST