* WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...A portion of central Pennsylvania, including the following counties, Cambria, Cameron, Clearfield, Elk, McKean, Somerset and Warren. * WHEN...From 4 PM EDT this afternoon through 4 AM EDT Sunday. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. * ADDITIONAL DETAILS... - Numerous heavy showers and thunderstorms may train across Central PA tonight with confidence in greatest rainfall totals highest across the Northwest Mountains and Laurel Highlands on PA. Rainfall rates of 1-2 inches per hour could lead to local storm totals in the range of 2-4 inches. - http://www.weather.gov/safety/flood