7/1/13, “Why this heat wave’s so scary and what’s behind it,” AP, Seth Borenstein
“Q: So what’s causing all this?
A: Part of it is normal summer heat spurts, said meteorologist Kenneth James of the Weather Prediction Center in College Park, Md. But there’s another factor and that’s the jet stream.
Normally the jet stream moves generally west-to-east, but when it slows and swings dramatically to the north or south, extreme weather can happen.
What’s happening now is “a really big kink in the jet stream, about as big as you can see anytime, covering the whole western U.S.,” said heat wave expert Ken Kunkel, a professor of atmospheric sciences at North Carolina State University.
To the west of the kink, in Arizona and Nevada, there’s a high pressure system just parked there with stagnant heat, Kunkel said. And to its east are cool — even record cool — temperatures in Texas, he said.
Q: When will it end?
A: The extreme heat should continue for about a week, but it won’t set records, James said.”…
Comment: The AP headline didn’t match the story.