Kevin Myatt is The Roanoke Times' weather columnist.

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We're all going to be under a big tent full of hot air -- and no, I'm not talking about the election season.

Stagnant, hot air has been building over the south-central United States the past several days. That dome of high pressure -- the big tent, if you will -- is expanding eastward, and we'll be under it by this weekend, with temperatures topping 90 in much of Southwest Virginia.

Several days next week look like strong bets for highs in the mid 90s or higher in Roanoke.

The exact location of highs, lows and fronts will determine whether we have a three-day hot spell or a weeklong heat wave in which temperatures flirt with 100 daily.

Whether this becomes a historic heat wave or just a brief patch of sticky heat also depends on a lot of local details.

If light westerly winds develop, as often happened in last year's roasting August, the heating and drying process of hot air being compressed as it is shoved down the eastern slopes of our Appalachian ridges could push temperatures above 100 degrees.

On the flip side, any clusters of thunderstorms that form in the Ohio Valley and manage to make it across the mountains into Virginia could disrupt the heat. Even storms that die on the way can send out a cooling burst of wind.

There is a tricky trade-off between heat and humidity. The more humid it is, the worse it can feel as the heat index rises. But more humidity can also keep the temperature from rising as fast and also makes it more possible for heat-reducing clouds and storms to develop. Drier air doesn't feel as sultry, but can allow heating to occur faster.

Enough humidity will be hanging around on many days to allow some showers and thunderstorms to crop up in afternoon heating, but anything that develops won't move much, so cooling effects will be very localized.

Record highs for Roanoke are unlikely Monday and Tuesday -- the records are 103 for Aug. 4 and 105 for Aug. 5, each set in 1930. Sunday's record is 100, set in 1963 -- reachable, but doubtful. Any 100-degree high temperature would make this the first time in 20 years that Roanoke has reached triple digits on at least one day in consecutive years.

I know some people who would actually vote for 100-degree heat over snow, though, among the Weather Journal constituency, they are a fringe party.

But fall really isn't that far away now. This kind of heat will be long behind us by Election Day.