Active AlertsBig Sky, MT

What: Flash flooding caused by excessive rainfall continues to be possible.
Where: A portion of southwest Montana, including the following areas, Gallatin and Madison County Mountains and Centennial Mountains, Northwest Beaverhead County and Ruby Mountains and Southern Beaverhead Mountains.
When: Until midnight MDT tonight.
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.
Additional Details: - Slow moving thunderstorms capable of producing heavy rain are expected through the evening. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.