Yellowstone National Park, Wyoming

Regional Weather Alerts


     

Alert: Flood Watch
Area(s): Helena Valley; Meagher County Valleys; Canyon Ferry Area; Gallatin Valley
Effective: 2026-09-19 @ 11:06 am -> 2026-09-19 @ 7:00 pm
Onset: 2026-09-19 @ 11:06 am -> 2026-09-19 @ 7:00 pm
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Great Falls MT on 2026-09-19 @ 11:06 am
Headline: Flood Watch issued September 19 at 10:06AM MDT until September 19 at 6:00PM MDT by NWS Great Falls MT
Description: * WHAT...Flooding caused by excessive rainfall continues to be
possible.

* WHERE...The Canyon Ferry Area, Helena Valley, and Meagher County
Valleys in Central Montana

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Excessive runoff may result in flooding of low-lying and
flood-prone locations.

* ADDITIONAL DETAILS...
- An area of rain will bring additional precipitation amounts to
around 0.5 inch today, with locally higher amounts near the
mountains.
- Some locations impacted include Helena, Townsend, White Sulphur
Springs, and Bozeman.
- 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
Effective: 2026-09-19 @ 11:06 am -> 2026-09-19 @ 7:15 pm
Onset: 2026-09-19 @ 11:06 am -> 2026-09-20 @ 1:00 am
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Great Falls MT on 2026-09-19 @ 11:06 am
Headline: Flash Flood Watch issued September 19 at 10:06AM 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...A portion of central Montana, including the following
areas, Big Belt, Bridger and Castle Mountains, Elkhorn and Boulder
Mountains and Little Belt and Highwood Mountains.

* WHEN...Through this evening.

* IMPACTS...Heavy rainfall over the Horse Gulch area and burn scars
from the summer of 2026 is expected up to and during the period of
the watch. Residents near the 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 Advisory
Area(s): Garfield, MT; McCone, MT; Prairie, MT
Effective: 2026-09-19 @ 9:13 am -> 2026-09-19 @ 2:15 pm
Onset: 2026-09-19 @ 9:13 am -> 2026-09-19 @ 2:15 pm
Severity: Minor
Certainty: Likely
Urgency: Expected
Issued By: NWS Glasgow MT on 2026-09-19 @ 9:13 am
Headline: Flood Advisory issued September 19 at 8:13AM MDT until September 19 at 1:15PM MDT by NWS Glasgow MT
Description: * WHAT...Flooding caused by excessive rainfall is expected.

* WHERE...Southern Garfield County in northeastern Montana...
South Central McCone County in northeastern Montana...
Prairie County in northeastern Montana...

* WHEN...Until 115 PM MDT.

* IMPACTS...Minor flooding in low-lying and poor drainage areas.
Water over roadways.

* ADDITIONAL DETAILS...
- At 809 AM 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 2 inches of rain have
fallen.
- Additional rainfall amounts of 0.5 to 2 inches are expected over
the area. This additional rain will result in minor flooding and
could make it nearly impassable on unpaved roadways today.
- Some locations that will experience flooding include...
Terry, Fallon, Hillside, Cohagen, Edwards, Sand Springs, Crow
Rock, Mccloud, Zero and Calypso.
- http://www.weather.gov/safety/flood

Alert: Flood Advisory
Area(s): Broadwater, MT; Meagher, MT
Effective: 2026-09-19 @ 8:46 am -> 2026-09-19 @ 2:45 pm
Onset: 2026-09-19 @ 8:46 am -> 2026-09-19 @ 2:45 pm
Severity: Minor
Certainty: Likely
Urgency: Expected
Issued By: NWS Great Falls MT on 2026-09-19 @ 8:46 am
Headline: Flood Advisory issued September 19 at 7:46AM MDT until September 19 at 1:45PM MDT by NWS Great Falls MT
Description: * WHAT...Flooding caused by excessive rainfall is expected.

* WHERE...Central Meagher County in central Montana...
East Central Broadwater County in southwestern Montana...

* WHEN...Until 145 PM MDT.

* IMPACTS...Minor flooding in low-lying and poor drainage areas.
River or stream flows are elevated.

* ADDITIONAL DETAILS...
- At 746 AM MDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Between 1.5 and 3 inches of rain
have fallen.
- Some locations that will experience flooding include...
Mainly rural areas of Central Meagher and East Central Broadwater
Counties.
- http://www.weather.gov/safety/flood

Alert: Flood Watch
Area(s): Musselshell; Treasure; Northern Rosebud; Custer; Fallon; Northern Stillwater; Powder River; Carter; 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: 2026-09-19 @ 7:42 am -> 2026-09-20 @ 7:45 am
Onset: 2026-09-19 @ 7:42 am -> 2026-09-20 @ 7:00 pm
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Billings MT on 2026-09-19 @ 7:42 am
Headline: Flood Watch issued September 19 at 6:42AM MDT until September 20 at 6:00PM MDT by NWS Billings MT
Description: A slow moving weather system will continue to impact the region
through Sunday. Thunderstorms embedded in the more general rainfall
have the potential to produce flash flooding, particularly over
recent burn scars.

* WHAT...Flooding caused by excessive rainfall is possible, along
with flash flooding over recent burn scars.

* WHERE...All of South Central and Southeast Montana, and Sheridan
County Wyoming.

* WHEN...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...
- Total rainfall amounts between 1 and 3 inches will be common
across the watch area. Locally heavier totals over 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. Any other burn scars from this summer will have elevated
Flash Flood potential as well.
- http://www.weather.gov/safety/flood

Alert: Flood Watch
Area(s): Petroleum; Garfield; Dawson; Prairie; Wibaux
Effective: 2026-09-19 @ 3:01 am -> 2026-09-19 @ 6:15 pm
Onset: 2026-09-19 @ 7:00 am -> 2026-09-20 @ 7:00 pm
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Glasgow MT on 2026-09-19 @ 3:01 am
Headline: Flood Watch issued September 19 at 2:01AM MDT until September 20 at 6:00PM MDT by NWS Glasgow MT
Description: * WHAT...Flooding caused by excessive rainfall is possible.

* WHERE...A portion of northeast Montana, including the following
counties, Dawson, Garfield, Petroleum, Prairie and Wibaux.

* WHEN...From 6 AM MDT this morning through Sunday afternoon.

* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks.

* ADDITIONAL DETAILS...
- Heavy rain is expected along and south of MT 200 between Winnett,
Jordan and Glendive and south of I 94 between Glendive and Wibaux
today, tonight, and Sunday morning. Between one and two inches of
rain is likely with heavier rain possible in embedded
thunderstorms.
- http://www.weather.gov/safety/flood

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