UPDATE: At 8 a.m. Sunday, the National Weather Service issued a red flag warning for Malheur County. Thunderstorms are “expected to become scattered late afternoon and lasting into early evening.”
The National Weather Service is forecasting “dangerously hot conditions” in the Treasure Valley coupled with a threat of thunderstorms Sunday afternoon.
The temperature in Ontario is forecast to hit 103 on Sunday and reach 100 degrees for at least four days, according to the Weather Service.
"Dangerously hot conditions with temperatures up to 105 expected," the forecast said.
A front moving up from California is expected to trigger thunderstorms across central and eastern Oregon, with a 20 percent chance of such storms forecast for the Malheur County area.
In the Treasure Valley area, “This moisture combines with intense daytime heating to bring a threat . . .