* WHAT...Flooding caused by excessive rainfall is possible. * WHERE...A portion of northwest Washington, including the following counties, Skagit and Whatcom. * WHEN...Through Tuesday morning. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - Heavy rainfall over the northern Cascades has diminished but what has already fallen continues to force rises on the rivers flowing off the mountains in the watch area. The Skagit River will approach flood stage tonight and Nooksack River tomorrow morning with flooding possible. - http://www.weather.gov/safety/flood