* WHAT...Flooding caused by excessive rainfall is possible. * WHERE...A portion of west central Texas, including the following counties, Concho, Crockett, Irion, Kimble, Mason, McCulloch, Menard, San Saba, Schleicher, Sutton and Tom Green. * WHEN...From 9 PM CDT this evening through Friday evening. * 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 crossin