...FLOOD WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH FRIDAY EVENING... * WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...Portions of Montana, including the following counties, Big Horn, Carbon, Golden Valley, Musselshell, Park, Rosebud, Stillwater, Sweet Grass, Treasure, Wheatland and Yellowstone. Portions of north central Wyoming, including the following county, Sheridan. * WHEN...From Thursday afternoon through Friday evening. * IMPACTS...Excessive runoff may result in flooding of creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. Storm drains and ditches may become clogged with debris. Burn scars may experience debris flow. * ADDITIONAL DETAILS... - Periods of showers and thunderstorms producing very heavy rainfall are expected over the watch area. - http://www.weather.gov/safety/flood