Yellowstone National Park, Wyoming

Regional Weather Alerts


     

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: Flash Flood Watch
Area(s): Helena Valley; Big Belt, Bridger and Castle Mountains; Canyon Ferry Area
Effective: 2026-08-12 @ 4:50 am -> 2026-08-12 @ 6:00 pm
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 @ 4:50 am
Headline: Flash Flood Watch issued August 12 at 3:50AM 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...From 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. Additional heavy rainfall is possible
Thursday and Friday, and additional flood statements might be
needed for those days as well.
- 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: 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.

Alert: Air Quality Alert
Area(s): Beaverhead, MT; Deer Lodge, MT; Flathead, MT; Gallatin, MT; Granite, MT; Jefferson, MT; Lake, MT; Lewis and Clark, MT; Lincoln, MT; Madison, MT; Mineral, MT; Missoula, MT; Park, MT; Powell, MT; Ravalli, MT; Sanders, MT; Silver Bow, MT
Effective: 2026-08-11 @ 9:15 am -> 2026-08-12 @ 10:00 am
Onset: 2026-08-11 @ 9:15 am
Severity: Unknown
Certainty: Unknown
Urgency: Unknown
Issued By: NWS Great Falls MT on 2026-08-11 @ 9:16 am
Headline: Air Quality Alert issued August 11 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, Gallatin, Granite, Madison,
Park, Flathead, Jefferson, Lake, Lewis and Clark, Lincoln, Mineral,
Missoula, Powell, Ravalli, and Silver Bow counties in effect until
9AM on 08/12/2026
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 08/11/2026, particulate levels in Missoula are
Unhealthy.

As of 8AM on 08/11/2026, particulate levels in Dillon, Frenchtown,
Great Falls and Hamilton are Unhealthy for Sensitive Groups.

As of 8AM on 08/11/2026, particulate levels in Billings, Butte,
Choteau, Columbia Falls, Cut Bank, Helena, Lewistown, Libby, Malta,
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): Broadwater, MT; Sweet Grass, MT; Yellowstone, MT
Effective: 2026-08-11 @ 9:15 am -> 2026-08-12 @ 10:00 am
Onset: 2026-08-11 @ 9:15 am
Severity: Unknown
Certainty: Unknown
Urgency: Unknown
Issued By: NWS Great Falls MT on 2026-08-11 @ 9:16 am
Headline: Air Quality Alert issued August 11 at 8:15AM MDT by NWS Great Falls MT
Description: AQAMT

The Air Quality Alert for Broadwater, Sweet Grass and Yellowstone
Counties has been cancelled.

For more information visit the Montana Department of Environmental
Quality at www.todaysair.mt.gov