Flood Watch issued April 27 at 3:46AM MDT until April 29 at 12:00AM MDT by NWS Billings MT

Runoff from a combination of heavy rain and some mid elevation snow
melt may cause flooding of streams and low lying areas in and
downstream of the foothills. Moderate to heavy rainfall over recent
burn areas (Robertson Draw and American Fork) may produce flash
flooding in and downstream of the burned area.

* WHAT…Flooding caused by rain and snowmelt remains a threat.

* WHERE…Portions of south central Montana, including the following
areas, Bighorn Canyon, Pryor/Northern Bighorn Mountains and
Southern Big Horn and north central Wyoming, including the
following areas, Northeast Bighorn Mountains and Sheridan
Foothills.

* WHEN…From this evening through Monday evening.

* IMPACTS…Excessive runoff may result in flooding of streams and
other low-lying and flood-prone locations close to the foothills.
Some roads may become impassable. Now is the time to move
equipment and livestock to higher ground away from waterways.
Recent burn scars may be more susceptible to produce flash
flooding, including the Elk burn scar west of Dayton and Sheridan.

* ADDITIONAL DETAILS…
– Scattered showers and thunderstorms this evening will turn to
more persistent rain into the overnight hours. Snow levels
will fall from 9500 feet this evening to around 5000 feet
Monday morning. Rain falling on snow may melt 1 to 3 inches
of snow water before cooler temperatures change precipitation
to snow in the foothills, ending the snowmelt. The
combination of precipitation and snowmelt may result in a 2
to 4 inch water event with rapid runoff filling small streams
and creeks along the foothills.
– http://www.weather.gov/safety/flood