The National Weather Service in Great Falls has issued a Flood Warning for rain and snowmelt in areas of southeastern Teton County and northwestern Cascade County.
The warning is in effect until 11:15 a.m. on Thursday, May 17th.
The NWS says that water levels along the Sun River continue to rise due to ongoing snowmelt. Rises will increase more quickly as showers and thunderstorms develop along the Sun River and its tributaries over the next couple of days.
Flood stage will be reached later this evening or tonight at Simms and Fort Shaw, cresting at 8.7 feet by Saturday. Flood stage is expected to be reached at Vaughn by late Thursday or Friday, cresting at 6.7 feet on Saturday.
Locations that will experience flooding include Fort Shaw, Vaughn, Simms, and Sun River.
Significant inundation is expected across portions of the town of Sun River and surrounding low lying areas. Flood waters will impact Highway 200 through Sun River.
Near Vaughn, flood waters will mostly impact low lying agricultural areas.
Flooding of nearby small creeks and streams, country roads, farmland, and other low lying spots is expected as river levels rise along the Sun River.
Areas not currently experiencing flooding may begin to see flooding as early as this evening.