Park County

Flood Watch issued September 19 at 6:42AM MDT until September 20 at 6:00PM MDT by NWS Billings MT

6:42 AM — September 20th, 6:45 AM

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

Flash Flood Watch issued September 19 at 3:09AM MDT until September 20 at 12:00AM MDT by NWS Great Falls MT

3:09 AM — 3:15 PM

* 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

Flood Watch issued September 19 at 3:09AM MDT until September 19 at 6:00PM MDT by NWS Great Falls MT

3:09 AM — 3:15 PM

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...Portions of central and southwest Montana, including the following areas, in central Montana, Canyon Ferry Area, Helena Valley and Meagher County Valleys. In southwest Montana, Gallatin Valley. * WHEN...Through this afternoon. * 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 1.00 inch today with locally higher amounts near the mountains. - http://www.weather.gov/safety/flood

Flood Watch issued September 19 at 1:34AM MDT until September 20 at 6:00PM MDT by NWS Riverton WY

1:34 AM — 6:00 PM

* WHAT...Flash flooding caused by moderate to heavy rainfall is possible, especially in terrain and poor drainage areas. * WHERE...Portions of central, north central, and northwest Wyoming, including the following areas, in central Wyoming, Owl Creek and Bridger Mountains. In north central Wyoming, Bighorn Mountains Southeast, Bighorn Mountains West, Northeast Johnson County and Southeast Johnson County. In northwest Wyoming, Absaroka Mountains, Cody Foothills and Yellowstone National Park. * WHEN...Through Sunday afternoon. * IMPACTS...Excessive rainfall may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas and around steep terrain. * ADDITIONAL DETAILS... - A slow moving weather system will move across Wyoming today through Sunday and bring rounds of showers and thunderstorms to the region, especially northern Wyoming. Any shower or thunderstorm could produce moderate to heavy rainfall across the Watch Area. - http://www.weather.gov/safety/flood

Flood Advisory issued September 19 at 7:46AM MDT until September 19 at 1:45PM MDT by NWS Great Falls MT

7:46 AM — 1:45 PM

* 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

Hydrologic Outlook issued September 18 at 10:20AM MDT by NWS Riverton WY

September 18th, 10:20 AM — 12:00 PM

ESFRIW A wet weather system will support periods of showers and thunderstorms across Wyoming Friday, Saturday, and Sunday. This weather system is funneling abundant tropical moisture into the state. Given this anomalously high moisture, many thunderstorms will feature heavy rainfall, possibly leading to localized flooding. Poor drainage areas, urban areas, and steep terrain will be the most susceptible locations for this isolated flooding. Many locations could see rainfall totals anywhere between 0.75" to 1.75" through Sunday afternoon, with a majority of this rain falling quickly in thunderstorms. Remember, if you encounter a flooded roadway, turn around don't down!