Hydrologic Outlook issued February 20 at 3:25AM MST by NWS Billings MT

ESFBYZ

An deep and wet snowpack exists across the forecast area after
a record setting February snowfall. 1 to 4 inches of water is
locked in this snowpack. Much warmer temperatures forecast over
the coming days will increase snowmelt, releasing this water.
With the ground frozen, water will not be able to soak in and
will run off. Water flowing overland and accumulating in low lying
areas may result in localized flooding. Water flowing into creeks
and streams will increase the potential for ice jam development
and may result in additional flooding near waterways. Localized
impacts from snowmelt may develop as soon as Friday over the
western foothills and valleys. More widespread impacts are
possible by the end of the weekend into early next week as
overnight low temperatures hover above freezing, producing 24
hour snowmelt potential.

Impacts…Water may accumulate near home foundations increasing
the chance of basement flooding. Plugged culverts, ditches, and
storm drains may result in water on area roadways at times. Water
flowing into creeks and streams will increase the potential for
ice jam development with additional flooding hazards. Unpaved
roads may suddenly thaw and become muddy and impassable. The
severity of the impacts will depend on how quickly the snowpack
melts, how fast the ground thaws, and any precipitation.

Preparation…While flooding is not imminent, if you have not
already done so, now is the time to move equipment and livestock
out of low lying areas, and away from waterways. Move any heavy
accumulations of snow away from structures and take steps to
prevent water from making it into basements. Clear any outside
drains of snow. Do not drive over flooded roadways as the roadbed
may be washed out. Be especially careful driving at night when
water covered roadways are less visible.

Stay tuned to the forecast for the latest temperature and
precipitation trends, along with any warnings or advisories that
may be issued. Please report any flooding to local law enforcement
and have them relay the report to the National Weather Service.