There's no relief in sight for firefighters battling several large wildfires in Washington state, and a lightning storm forecast to sweep through the region Saturday could ignite even more blazes and bring little to no rain.

For weeks, thousands of firefighters have been working to steer the fires away from scattered hillside homes and entire communities, awaiting the fall rains or mountain snow that typically end the wildfire season. The fires are burning on 143 square miles of parched forest, brush and grass.

Thick smoke has blanketed the immediate area of the fires and beyond, forcing one school district to cancel classes entirely. State health officials sent more than 20,000 respirator masks to the region in anticipation of possible shortages.

And still, the wait continues.

Saturday's storm could bring lightning to western Washington and up and down the Cascade Range, with the hardest-hit area likely to be the central region, National Weather Service meteorologist Steven Van Horn said.