If you want to visualize how a heat dome can trap a region in intensely hot weather, picture yourself making a grilled cheese sandwich. It almost acts like a lid on a pot, the National Weather Service's Alex Lamers tells NPR. He's the operations branch chief at the Weather Prediction Center. If you've made grilled cheese in a pan and you put a lid on there, it melts the cheese faster because the lid helps trap the heat and makes it a little bit warmer, Lamers says.
It's a similar concept here: You get a big high-pressure system in the upper parts of the atmosphere and it allows that heat to build underneath over multiple days. The heat dome that's currently putting a hot lid on the Western U.S. will bring high temperatures that are 20 to 30 degrees hotter than normal for early June, the National Weather Service said.
Some 20 million Americans, from California to Texas, were living under a federal excessive heat advisory as of Wednesday, with forecasters issuing alarms about the heat dome in the Western U.S. Another 11 million people were under heat advisories.
We're going to be 108 or 109 starting [Thursday], and that will persist for three days, which is consistent with our definition of a heat wave, although we've been over 100 now for more than a week.
[
add
]
[
|
|
...
]