The National Weather Service has issued a flood watch for Schuylkill County from 6 p.m. today through Thursday morning.
Kevin Fitzgerald, a meteorologist with the National Weather Service in State College, said Monday the "greatest threat" will be Wednesday evening.
"That's when the hardest rain will fall," he said.
The rain should end by dawn Thursday, Fitzgerald said.
"Right now, we're looking at 2 to 4 inches," he added.
According to the NWS website, 3 to 5 inches are expected through Wednesday night.
Minor flooding is possible, Fitzgerald said.
"There's going to be a wet period here for the next couple of days," he said, adding he did not think there would be a "big flood event" because the ground is relatively dry.