Yellowstone National Park, Wyoming
Regional Weather Alerts
| Alert: | Special Weather Statement |
| Area(s): | Northern Sweet Grass; Melville Foothills; Southern Wheatland |
| Effective: | 2026-08-12 @ 5:49 pm -> 2026-08-12 @ 6:30 pm |
| Onset: | 2026-08-12 @ 5:49 pm |
| Severity: | Moderate |
| Certainty: | Observed |
| Urgency: | Expected |
| Issued By: | NWS Billings MT on 2026-08-12 @ 5:49 pm |
| Headline: | Special Weather Statement issued August 12 at 4:49PM MDT by NWS Billings MT |
| Description: |
At 449 PM MDT, Doppler radar was tracking a strong thunderstorm 18 miles south of Harlowton, moving east at 20 mph. HAZARD...Wind gusts up to 40 mph and half inch size hail. SOURCE...Radar indicated. IMPACT...Gusty winds could knock down tree limbs and blow around unsecured objects. Minor damage to outdoor objects is possible. Locations impacted include... Mainly rural areas of South Central Wheatland and North Central Sweet Grass Counties. |
| Alert: | Special Weather Statement |
| Area(s): | Little Belt and Highwood Mountains; Big Belt, Bridger and Castle Mountains; Meagher County Valleys |
| Effective: | 2026-08-12 @ 5:34 pm -> 2026-08-12 @ 6:15 pm |
| Onset: | 2026-08-12 @ 5:34 pm |
| Severity: | Moderate |
| Certainty: | Observed |
| Urgency: | Expected |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 5:34 pm |
| Headline: | Special Weather Statement issued August 12 at 4:34PM MDT by NWS Great Falls MT |
| Description: |
At 434 PM MDT, Doppler radar was tracking a strong thunderstorm 25 miles east of White Sulphur Springs, moving east at 15 mph. HAZARD...Wind gusts up to 40 mph and half inch hail. SOURCE...Radar indicated. IMPACT...Gusty winds could knock down tree limbs and blow around unsecured objects. Minor hail damage to vegetation is possible. Locations impacted include... Martinsdale. |
| Alert: | Flood Advisory |
| Area(s): | Carter, MT |
| Effective: | 2026-08-12 @ 4:27 pm -> 2026-08-12 @ 6:15 pm |
| Onset: | 2026-08-12 @ 4:27 pm -> 2026-08-12 @ 6:15 pm |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Billings MT on 2026-08-12 @ 4:27 pm |
| Headline: | Flood Advisory issued August 12 at 3:27PM MDT until August 12 at 5:15PM MDT by NWS Billings MT |
| Description: |
* WHAT...Flooding caused by excessive rainfall continues. * WHERE...Northwestern Carter County in southeastern Montana... * WHEN...Until 515 PM MDT. * IMPACTS...Minor flooding in low-lying and poor drainage areas. Overflowing poor drainage areas. River or stream flows are elevated. * ADDITIONAL DETAILS... - At 325 PM MDT, Doppler radar indicated heavy rain due to thunderstorms. Minor flooding is ongoing or expected to begin shortly in the advisory area. Between 1 and 3 inches of rain have fallen. - Additional rainfall amounts up to 0.5 inches are expected over the area. This additional rain will result in minor flooding. - Some locations that will experience flooding include... Mainly rural areas of Northwestern Carter County. - http://www.weather.gov/safety/flood |
| Alert: | Flash Flood Watch |
| Area(s): | Helena Valley; Canyon Ferry Area |
| Effective: | 2026-08-12 @ 1:42 pm -> 2026-08-13 @ 5:00 am |
| Onset: | 2026-08-12 @ 5:00 pm -> 2026-08-13 @ 5:00 am |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 1:42 pm |
| Headline: | Flash Flood Watch issued August 12 at 12:42PM MDT until August 13 at 4:00AM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flash flooding and debris flows caused by excessive rainfall continue to be possible over the Horse Gulch burn scar. * WHERE...A portion of central Montana, including the following areas, Horse Gulch burn scar, including Riverside Campground. * WHEN...From 4 PM MDT this afternoon through late tonight. * IMPACTS...Heavy rainfall over the Horse Gulch burn scar is expected up to and during the period of the watch. Residents near the Horse Gulch burn scar 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 the Horse Gulch burn scar, which may lead to flash flooding and debris flows. - Some locations that may experience flash flooding include... Horse Gulch burn scar and Riverside Campground. - For flood safety, go to this web page. http://www.weather.gov/safety/flood |
| Alert: | Flash Flood Watch |
| Area(s): | Big Belt, Bridger and Castle Mountains |
| Effective: | 2026-08-12 @ 1:42 pm -> 2026-08-13 @ 7:00 am |
| Onset: | 2026-08-12 @ 5:00 pm -> 2026-08-13 @ 5:00 am |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 1:42 pm |
| Headline: | Flash Flood Watch issued August 12 at 12:42PM MDT until August 13 at 4:00AM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flash flooding and debris flows caused by excessive rainfall are possible over the Horse Gulch burn scar. * WHERE...A portion of central Montana, including the following areas, Horse Gulch burn scar, including Riverside Campground. * WHEN...Thursday evening. * IMPACTS...Heavy rainfall over the Horse Gulch burn scar is expected up to and during the period of the watch. Residents near the Horse Gulch burn scar 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 the Horse Gulch burn scar, which may lead to flash flooding and debris flows. Additional heavy rainfall is possible on Friday, and additional flood statements may be needed over the coming days. - Some locations that may experience flash flooding include... Horse Gulch burn scar and Riverside Campground. - For flood safety, go to this web page. http://www.weather.gov/safety/flood |
| Alert: | Flash Flood Watch |
| Area(s): | Big Belt, Bridger and Castle Mountains |
| Effective: | 2026-08-12 @ 1:42 pm -> 2026-08-13 @ 7:00 am |
| Onset: | 2026-08-13 @ 7:00 pm -> 2026-08-14 @ 1:00 am |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 1:42 pm |
| Headline: | Flash Flood Watch issued August 12 at 12:42PM MDT until August 14 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 burn scar. * WHERE...A portion of central Montana, including the following areas, Horse Gulch burn scar, including Riverside Campground. * WHEN...Thursday evening. * IMPACTS...Heavy rainfall over the Horse Gulch burn scar is expected up to and during the period of the watch. Residents near the Horse Gulch burn scar 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 the Horse Gulch burn scar, which may lead to flash flooding and debris flows. Additional heavy rainfall is possible on Friday, and additional flood statements may be needed over the coming days. - Some locations that may experience flash flooding include... Horse Gulch burn scar and Riverside Campground. - For flood safety, go to this web page. http://www.weather.gov/safety/flood |
| Alert: | Air Quality Alert |
| Area(s): | Beaverhead, MT; Deer Lodge, MT; Granite, MT; Madison, MT; Missoula, MT; Ravalli, MT; Silver Bow, MT |
| Effective: | 2026-08-12 @ 9:15 am -> 2026-08-13 @ 10:00 am |
| Onset: | 2026-08-12 @ 9:15 am |
| Severity: | Unknown |
| Certainty: | Unknown |
| Urgency: | Unknown |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 9:20 am |
| Headline: | Air Quality Alert issued August 12 at 8:15AM MDT by NWS Great Falls MT |
| Description: |
AQAMT The Montana Department of Environmental Quality has issued an air quality alert for Beaverhead, Deer Lodge, Granite, Silver Bow, Madison, Missoula, Ravalli counties in effect until 9AM on 08/13/2026 An Air Quality Alert means that particulates have been trending upwards and that an exceedance of the 24 hour National Ambient Air Quality Standard (NAAQS) has occurred or may occur in the near future. Elevated particulate levels from wildfire smoke As of 8AM on 08/12/2026, particulate levels in Dillon are Unhealthy. As of 8AM on 08/12/2026, particulate levels in Frenchtown and Missoula are Unhealthy for Sensitive Groups. As of 8AM on 08/12/2026, particulate levels in Billings, Butte, Choteau, Columbia Falls, Cut Bank, Great Falls, Hamilton, Havre, Helena, Lewistown, Libby, Malta, Sleeping Giant, Thompson Falls and West Yellowstone are Moderate. When air quality is Unhealthy... State and local health officials recommend that people with respiratory or heart disease, the elderly, and children should avoid prolonged exertion; everyone else should limit prolonged exertion. When air quality is Unhealthy for Sensitive Groups... State and local health officials recommend that people with respiratory or heart disease, the elderly and children should limit prolonged exertion. When air quality is Moderate... State and local health officials recommend that unusually sensitive people should consider reducing prolonged or heavy exertion. For more information visit the Montana Department of Environmental Quality at http://todaysair.mtdeq.us |
| Alert: | Air Quality Alert |
| Area(s): | Flathead, MT; Gallatin, MT; Jefferson, MT; Lake, MT; Lewis and Clark, MT; Lincoln, MT; Mineral, MT; Park, MT; Powell, MT; Sanders, MT |
| Effective: | 2026-08-12 @ 9:15 am -> 2026-08-13 @ 10:00 am |
| Onset: | 2026-08-12 @ 9:15 am |
| Severity: | Unknown |
| Certainty: | Unknown |
| Urgency: | Unknown |
| Issued By: | NWS Great Falls MT on 2026-08-12 @ 9:20 am |
| Headline: | Air Quality Alert issued August 12 at 8:15AM MDT by NWS Great Falls MT |
| Description: |
AQAMT The Air Quality Alert for Flathead, Gallatin, Jefferson, Lake, Lewis and Clark, Lincoln, Mineral, Park, Powell and Sanders Counties has been cancelled. For more information visit the Montana Department of Environmental Quality at www.todaysair.mt.gov |
| Alert: | Lake Wind Advisory |
| Area(s): | Flathead/Mission Valleys |
| Effective: | 2026-08-12 @ 3:22 am -> 2026-08-13 @ 1:00 am |
| Onset: | 2026-08-12 @ 7:00 pm -> 2026-08-13 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-08-12 @ 3:22 am |
| Headline: | Lake Wind Advisory issued August 12 at 2:22AM MDT until August 13 at 12:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Northeast winds 15 to 25 mph with gusts up to 40 mph expected. * WHERE...Flathead Lake and smaller lakes across the Flathead and Mission Valley region. * WHEN...From 6 PM this evening to midnight MDT tonight. * IMPACTS...Strong winds and rough waves on area lakes will create hazardous conditions for small craft. |