Effective:

2025-02-24T08:43:00-07:00

Expires:

2025-02-26T12:00:00-07:00

Certainty:

Possible

Event:

Hydrologic Outlook

Type:

Alert

Severity:

Unknown

Urgency:

Future

Areas:

Big Horn, MT; Carbon, MT; Carter, MT; Custer, MT; Fallon, MT; Golden Valley, MT; Musselshell, MT; Park, MT; Powder River, MT; Rosebud, MT; Stillwater, MT; Sweet Grass, MT; Treasure, MT; Wheatland, MT; Yellowstone, MT; Sheridan, WY

ESFBYZ A deep and wet snowpack exists across the forecast area. Up to an inch of snow water has melted out of this snowpack over the past few days. This still leaves 1 to 3 inches (more in some areas such as the Wolf Mountains) of water remaining. Continued warm temperatures forecast over the coming days will accelerate snowmelt, releasing this water. With the ground still 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. 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.

Instruction:

Effective:

2025-02-23T13:34:00-07:00

Expires:

2025-02-24T16:00:00-07:00

Certainty:

Possible

Event:

Hydrologic Outlook

Type:

Alert

Severity:

Unknown

Urgency:

Future

Areas:

Big Horn, WY; Hot Springs, WY; Johnson, WY; Park, WY; Washakie, WY

ESFRIW Low elevation snowpack of around 4 to 10 inches exists across much of the northern portion of the Bighorn Basin including Greybull, Lovell, Powell, and Cody. This snowpack contains an estimated 1 to 3 inches of Snow Water Equivalent (SWE). Temperatures beginning are expected to climb into the low 40s to near 50 degrees each afternoon through next weekend. Warmest temperatures look to occur Friday through Sunday (Feb 28 - Mar 2). The warm temperatures, combined with the significant low elevation snowpack, could result in significant melting and injection into local rivers and streams. Ice break up on the Bighorn and Nowood Rivers is possible as well, and could lead to ice jamming and potential resultant flooding. Similar snowpack also exists across portions of northern Johnson County. Although the risk for ice jams is lower, ponding of water and overland runoff could fill culverts and other low-lying areas. Now would be the time to clear snow, ice, and debris from culverts and other flow paths to allow runoff to flow away from buildings and other vulnerable infrastructure. This could include moving deep snow away from the foundations of buildings, relocating equipment to higher ground, and moving livestock out of poorly drained or low- lying areas. Stay tuned for the latest river forecasts.

Instruction: