Kevin Myatt is The Roanoke Times' weather columnist.

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Weather with Kevin Myatt

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• Locals give storm chasers sunny reception
• 2012's balmy start could turn out to be record-setting
• Virginia Tech study: Supercells can amp up crossing ridges
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• A second “preseason” named tropical system may soon form off Southeast U.S. coast
• Headed for a hot Memorial Day weekend, after a day or two more of scattered downpours
• UPDATE 6:30 AM, 5/23: More showers and storms on Tuesday/Wednesday/Thursday; time to enter summer prediction contest
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Here's one way to slow down the rampant tornado season in the United States -- turn up the heat.

That's what appears to be happening during the next week or so. A large dome of high pressure will cover most of the U.S. east of the Rockies, bringing unseasonably hot temperatures as May rolls into June, and curbing the severe weather season over all but perhaps the northern tier of the United States. Temperatures will probably top 90 degrees even in Roanoke a few days next week.

There's a reason tornadoes don't happen as often in the summer as they do in the spring, why they don't happen as often in tropical areas as in regions with changing seasons, and why people who study tornadoes are hesitant to say that even a rise in the Earth's temperature is a factor in an above-average season.

When hotter summerlike weather builds, several things happen that deter the development of large outbreaks of tornadoes.

• Warmer air aloft can prevent hot air from the surface from rising as rapidly, thereby deterring thunderstorm development.
• Hot high pressure systems contain light winds aloft, insufficient to cause storms to rotate.
• Building high pressure over the U.S. pushes the jet stream farther north, taking the river of air pushing storm systems that can enhance tornadoes away from most of the U.S.

So the heat wave may actually be somewhat welcome news for swaths of the country devastated by tornadoes the past couple of months. The penalty, though, will be searing heat unusually early in the season.

Summer contest

The coming hot weather is a reminder that the summer prediction contest closes at midnight Sunday.

To enter, email your name, location of residence (city, town or part of county), a prediction for Roanoke's hottest temperature between June 1 and Aug. 31 and the date it will occur to weather@roanoke.com.

Taking a break

I'll be taking some time off from Weather Journal through mid-June. Part of that time will be the annual Virginia Tech storm chase trip -- actually the second of two trips, the first of which successfully viewed a tornado in Iowa the same day Joplin, Mo., was hit. Fortunately, it was a much weaker tornado with no loss of life.

We've bumped the trip up a couple of days to take advantage of one last springlike central U.S. severe weather setup on Memorial Day before the summer pattern sets in. Then, we'll just have to see what kind of storm systems can come in over the big high in the far northern states.