Yellowstone National Park, Wyoming
Regional Weather Alerts
| Alert: | Flash Flood Watch |
| Area(s): | Northwest Beaverhead County |
| Effective: | 2026-09-18 @ 4:21 am -> 2026-09-18 @ 4:15 pm |
| Onset: | 2026-09-18 @ 4:00 pm -> 2026-09-19 @ 7:00 pm |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-09-18 @ 4:21 am |
| Headline: | Flash Flood Watch issued September 18 at 3:21AM MDT until September 19 at 6:00PM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flash flooding and debris flows caused by excessive rainfall continue to be possible over the Sand Creek and Bobcat Lakes Burn Scars. * WHERE...A portion of southwest Montana, including the following area, Northwest Beaverhead County. * WHEN...From 3 PM MDT this afternoon through Saturday afternoon. * IMPACTS...Heavy rainfall over the Sand Creek and Bobcat Lakes Burn Scars is expected up to and during the period of the watch. Residents near the Sand Creek and Bobcat Lakes Burn Scars should prepare for potential debris flow. Be sure to stay up to date with information from local authorities. Heavy rainfall could trigger flash flooding of low-lying areas, urbanized street flooding, and debris flows in and near recent wildfire burn scars. * ADDITIONAL DETAILS... - Showers and thunderstorms capable of producing locally intense rainfall are forecast to develop over the burn scar late this afternoon through this evening with additional precipitation expected through Saturday, which may lead to flash flooding and debris flows. - Some locations that may experience flash flooding include... Areas near the Sand Creek and Bobcat Lakes Burn Scars, including portions of the Pioneer Mountains Scenic Byway. - http://www.weather.gov/safety/flood |
| Alert: | Flash Flood Watch |
| Area(s): | Little Belt and Highwood Mountains; Big Belt, Bridger and Castle Mountains; Elkhorn and Boulder Mountains; Gallatin Valley |
| Effective: | 2026-09-18 @ 4:21 am -> 2026-09-18 @ 4:15 pm |
| Onset: | 2026-09-18 @ 7:00 pm -> 2026-09-20 @ 1:00 am |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-09-18 @ 4:21 am |
| Headline: | Flash Flood Watch issued September 18 at 3:21AM MDT until September 20 at 12:00AM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flash flooding and debris flows caused by excessive rainfall are possible over the Horse Gulch area and burn scars from the summer of 2026. * WHERE...Portions of central and southwest Montana, including the following areas, in central Montana, Big Belt, Bridger and Castle Mountains, Elkhorn and Boulder Mountains and Little Belt and Highwood Mountains. In southwest Montana, Gallatin Valley. * WHEN...From this evening through Saturday evening. * IMPACTS...Heavy rainfall over the Horse Gulch and Burn Scars of 2026 is expected up to and during the period of the watch. Residents near he Horse Gulch area and burn scars from the summer of 2026 should prepare for potential debris flow. Be sure to stay up to date with information from local authorities. Heavy rainfall could trigger flash flooding of low-lying areas, urbanized street flooding, and debris flows in and near recent wildfire burn scars. * ADDITIONAL DETAILS... - National Weather Service Meteorologists are forecasting heavy rainfall over recent burn scars, which may lead to flash flooding and debris flows. - Some locations that may experience flash flooding include... Areas near recent burn scars from the summer 2026 and the Horse Gulch area. - http://www.weather.gov/safety/flood |
| Alert: | Flood Watch |
| Area(s): | Musselshell; Treasure; Northern Rosebud; Northern Stillwater; Powder River; Northern Park; Golden Valley; Red Lodge Foothills; Northern Big Horn; Southern Rosebud; Judith Gap; Paradise Valley; Livingston Area; Beartooth Foothills; Absaroka/Beartooth Mountains; Crazy Mountains; Southern Big Horn; Southeastern Carbon; Northern Sweet Grass; Bighorn Canyon; Northern Carbon; Pryor/Northern Bighorn Mountains; Melville Foothills; Northeastern Yellowstone; Southern Wheatland; Southwestern Yellowstone; Northeast Bighorn Mountains; Sheridan Foothills |
| Effective: | 2026-09-18 @ 3:50 am -> 2026-09-19 @ 4:00 am |
| Onset: | 2026-09-18 @ 7:00 pm -> 2026-09-20 @ 7:00 pm |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Billings MT on 2026-09-18 @ 3:50 am |
| Headline: | Flood Watch issued September 18 at 2:50AM MDT until September 20 at 6:00PM MDT by NWS Billings MT |
| Description: |
A strong and slow moving weather system will impact the region tonight through Sunday. Well above normal atmospheric moisture levels combined with the dynamics from this storm system will provide the potential for heavy rainfall during this period. Thunderstorms embedded in the more general rainfall will have the potential to produce flash flooding, particularly over recent burn scars. * WHAT...Flooding caused by excessive rainfall is possible, along with Flash Flooding of recent burn scars. * WHERE...All of South Central Montana, Portions of Southeast Montana, and Sheridan County Wyoming. * WHEN...From this evening through Sunday afternoon. * IMPACTS...Excessive runoff may result in flooding of creeks and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - 1 to 2.5 inches of rainfall is expected across the watch area tonight through Sunday. Locally heavier totals up to 4 inches are possible where thunderstorm activity is more persistent. - The Robertson Draw, East Side, Elk, and McGhee-Remington burn scars are particularly vulnerable to Flash Flooding and debris flows during the watch period. Any other burn scars from this summer will have elevated Flash Flood potential as well. - http://www.weather.gov/safety/flood |
