While states along the East Coast prepare for a possible hit by Hurricane Irene, the Northwestern U.S. is battling widespread, lightning-caused wildfires.

A lightning storm started a fire in Montana on Sunday, which has spread across the state and over to Idaho and Wyoming.

Fire conditions rose to critical Thursday, the Associated Press reported.

The Hole in the Wall Fire is 50 percent contained and 5,764 acres have been burned, Montana's KULR8.com reported Thursday evening.

Saddle Complex Fire grows to 21,152 acres. Red flag warning issued for this afternoon, Montana's Bitterroot National Forest Tweeted Thursday.

The fire also spread to eastern Idaho. There is a fast-growing 28,000-acre wildfire raging within miles of a U.S. Energy Department lab that is holding nuclear fuel, and it has been evacuated, Reuters reported.

A lightning storm in central Oregon started about 150 fires, the AP reported.

The Umpqua National Forest could get pretty active because of the number of strikes there, Northwest Interagency Fire Coordination Center spokesperson Mark Morrow said, The Oregonian reported Thursday evening.

The weather is not helping the situation either. There are patterns of hot, dry weather with afternoon storms.

Any time you have storms, it's not just the lightning that's the problem, it's the wind they're producing, National Weather Service meteorologist Joe Lester said, the AP reported. It's going to be an issue we have to keep watching through the weekend and into early next week.