Boise, ID -

National Weather Service warned Idaho residents traveling or recreating on National Forest lands to be wary of possible flash flooding, as recent wildfires have scorched what ordinarily would have been rain-sopping vegetation from hillsides.

A flash flood watch goes into effect at midnight and continues through Tuesday on Boise National Forest areas burned by the massive Elk, Pony and Little Queens fires.

Additionally, a flash flood watch is also in effect for the Payette National Forest where the Weiser Complex Fire has burned about 40 square miles along the Snake River near Brownlee Reservoir.

Forest managers say fire-hardened soil will repel rainfall, preventing it from soaking into the earth.

And heavy rain is expected in recently-burned areas, beginning Monday night.

As a consequence, creeks and rivers could swell quickly.