UPDATE: Second thunderstorm hits Treasure Valley Monday with violent late afternoon winds

A severe thunderstorm swept into Boise, the Emmett area and Southwestern Boise County Monday afternoon, the National Weather Service reports.

Winds of up to 70 mph are expected until around 4:45 p.m., and rain is expected to continue beyond that time, NWS Observation Program Leader Dave Decker said. The severe thunderstorm warning began at 4:20 p.m.

"We already had a gust of 61 at the airport," Decker said.

Earlier Monday, some Boise residents were awakened by the crash of thunder and rain bouncing off their roofs.

A disturbance formed around Mountain Home about 3 a.m. Monday and slowly moved northwest, bringing lightning and thunder to Boise two hours later.

It’s less common to have a thunderstorm hit the Treasure Valley right before daybreak but not unheard of, said Elizabeth Padian, a meteorologist with the National Weather Service in Boise.

“The disturbance formed without that afternoon heating that is usually the culprit,” Padian said.

The lightning and thunder were followed by strong winds that peaked at 50 mph at 5:52 a.m. Rain began falling at 6 a.m. In the first half-hour .15 of an inch of rain fell at the Boise Airport, Padian said.