Nebraska's record-setting heat wave explained, high pressure to blame
GRAND ISLAND, Neb. — One of the hottest weeks in decades is coming to a close in central and eastern Nebraska.
The heat wave has shattered daily records and will likely end up as the hottest six-day stretch in Grand Island since 1966. According to the National Weather Service, a heat dome has driven up temperatures in the desert southwest and south this whole summer. That weather is now making an impact on the plains.
“That high pressure has just shifted north, just enough, to really settle in over us for this week or so," NWS meteorologist Mike Moritz said. "That has really been the catalyst for our hot temperatures.”
Mike Moritz is the Warning Coordination Meteorologist with the NWS Hastings Office. He says high pressure is the key to high heat.
“High pressure builds over an area and that creates what we call a sinking flow," Moritz said. "We use a term subsidence. As the air sinks to the ground it will heat up.”
It’s a normal summer phenomenon, but not quite like this.
“It just so happens it’s a really strong high pressure and it’s creating abnormally warm temperatures across the area,” Moritz said.
The NWS says at least 14 daily high temperature and warm low temperature records have been tied or broken in Grand Island and Hastings in the last week. The daily temperatures are 18-20 degrees above what’s normal for late August.
“It has happened before, it just doesn’t happen very often," Moritz said. "That’s why we really want people to pay attention and heed the advice that’s out there. Ride this heat wave out, limit your activities, be careful and things will improve.”
Moritz says the extreme weather doesn’t have any bearing on future weather. The heat wave’s biggest long-term impact is how it’s worsened drought conditions in the eastern half of the state.
The good news? High temperatures will fall into the 80s starting on Saturday.