‘Heat bubbles’ don’t create a storm shield around city

This column was originally published Aug. 1, 2005:

So there was this foreman of a 10man building crew, and they were really lazy. He had a hard time getting a full day’s work out of them. So one day he decided to use a little reverse psychology on them, and he said, “I’ve got a really easy job today for one of you who doesn’t want to work much. Which one of you is laziest? Raise your hand.”

Nine guys raised their hands. And one guy just sat there.

“What about you?” the foreman said. “Why didn’t you raise your hand, too?”

And the guy says: “It was too much trouble.”

That’s a good one, huh? It doesn’t have anything to do with today’s question. I just thought it was a good joke.

The question is this:

This is in a way an appealing thought, an easy explanation for why storms seem to hit one part of town and not the other. Unfortunately, it is not true.

I know it is not true because I asked David Runyan, a meteorologist at the Phoenix office of the National Weather Service, and he told me so.

Says Runyan: “I think large cities, urban regions, play an important role in weather, in much the same way that huge wildfires actually begin to create weather environments. The rub is, what, or better yet, how does it affect?”

Big bubbles of heat can occur, but what does hot air do? It rises and adds to the makeup of thunderstorms.

Monsoon thunderstorms are complicated. They involve, in varying degrees, heat, moisture, wind and sunshine, and, as Runyan pointed out, too much of one ingredient or not enough of another determines the severity of the storm.

“Storms do not stop at our city’s doorstep or move around the border,” Runyan said. “If ‘the-heat-bubble-protects-us’ were really true, someone would come up with a ‘heat bubble shield’ concept and market it. Right?”

Right.