YAKIMA, Wash. — The National Weather Service has upgraded its fire weather watch over the Cascades and Columbia Basin to a red flag warning.

The warning, which goes into effect at 5 p.m. and continues till 8 a.m. Thursday, indicates that conditions are favorable for the rapid spread of wildfires. The notice, from the Weather Service’s Spokane office, predicts thunderstorms tonight over all of Eastern Washington, from the Cascades to Idaho.

“Thunderstorms over the Columbia Basin tonight will contain little rain,” the weather alert says. “The potential for abundant lightning combined with dry fuels may result in new fire starts across much of the region.”