A Flash Flood Watch will go into effect at 2 p.m. today and run through 2 a.m. Wednesday according to the National Weather Service in State College.
Beginning this afternoon, a front with move in from the west that will "keep showers and thunderstorms in the forecast," according to the NWS. The heaviest rain is expected today through Tuesday night over the southern half of Pennsylvania. Torrential rainfall is possible from any of the storms, which could lead to flash flooding.
The Flash Flood Watch will cover 22 counties, including Northumberland, Snyder and Union counties.
According to AccuWeather, a series of storms will produce rounds of drenching rain, torrential downpours and thunderstorms over a "swath from the Ohio Valley to the central Appalachians and mid-Atlantic coast this week. Through Friday, the area from Kentucky and southern Illinois through Pennsylvania, New Jersey, Maryland and Delaware will receive a general 2-4 inches of rain."