Web Portal Changes: The Advanced Hydrologic Prediction Service (AHPS) hosted at https://water.weather.gov will be replaced by the National Water Prediction Service (NWPS), with a target of March 2024. Existing AHPS content and features will be preserved and expanded within NWPS.

Experimental National Water Center Products: Flood Inundation Mapping services are now available for 10% of the U.S. population. Please visit https://www.weather.gov/owp/operations for more information. The National Hydrologic Discussion, Area Hydrologic Discussion, Flood Hazard Outlook, and real-time geospatial services depicting River Forecast Center and National Water Model forecasts, continue to be accessible via the URL above, as described in the StoryMap here.

Weather Forecast Office Great Falls, MT

Missouri Basin River Forecast Center

Hydrograph

River at a Glance

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Probability Information Weekly Chance of Exceeding Levels Chance of Exceeding Levels During Entire Period Short-term Probabilistic Guidance (Experimental)

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Printable Image About this graph Tabular Data (UTC) Tabular Data (MDT) Datum: Not Available Metadata

NOTE: Stage may be affected by ice during winter months. NOTE: Forecasts for the Sun River near Simms are issued as needed during times of high water, but are not routinely available.

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Upstream Gauge

Downstream Gauge

Flood Categories (in feet) Major Flood Stage: 10.5 Moderate Flood Stage: 8.5 Flood Stage: 7.5 Action Stage: 6 Low Stage (in feet): -9999 Historic Crests (1) 13.70 ft on 06/09/1964 (2) 12.48 ft on 06/20/1975 (3) 10.75 ft on 06/20/2018 (4) 9.87 ft on 06/08/2011 (5) 9.15 ft on 05/27/2019 Show More Historic Crests (P): Preliminary values subject to further review. Recent Crests (1) 9.15 ft on 05/27/2019 (2) 10.75 ft on 06/20/2018 (3) 8.10 ft on 05/12/2018 (4) 5.00 ft on 06/25/2014 (5) 4.98 ft on 06/09/2013 Show More Recent Crests (P): Preliminary values subject to further review. Low Water Records Currently none available. For more information on your flood risk go to www.floodsmart.gov. Show FEMA's National Flood Hazard Layers FEMA's National Flood Hazard Layers not showing? Why aren't the FEMA National Flood Hazard Layers showing on the ESRI Map? Possible reasons: There are no FEMA National Flood Hazard Layers for the location which you are viewing on ESRI Maps. The FEMA Web Mapping Service (WMS) is down. Note: Your zoom level may have changed. ESRI's zoom levels must be between 14 and 16 to show National Flood Hazard layers.

Zoom Level:16 Legend FEMA Layer Gauge Location Disclaimer Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.

Flood Impacts & Photos

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12	Major flooding. More than 100,000 acres flood.
10.8	At 10.8 Feet - June 20 2018 - Flooding in the city of Sun River similar to 2011. Most streets under water. Photos estimate water 2 to 4 feet deep. Highway 200 Closed from the 89 Junction all the way to the 287 Junction. Roger's Pass had a culvert washout which closed that section.
10.7	June 2018 - 1st and 2nd street flood in Sun River. Gravel washed away roadway, exposing optic cables. In Fort Shaw - North Fort Shaw Road completely destroyed. Culverts under roadway were exposed.
9.1	May 27, 2019 - At 9.1 feet - Streets and homes in Sun River flooded. Not as bad as the 2018 flood. Highway 200 had water over the highway, with flaggers. Water around homes. Fields did flood.
9	Much of the valley is flooded. Highway 200 flooded. Many homes as well as agricultural land floods.
8.5	Hwy 200 through town of Sun River, between 1st St and 3rd St, under water. Significant inundation of town between river to W, N, and E of town to beyond W Carroll St/Steell St. Sun River-Cascade Rd inundated for approx 1/3 mile to south of town.
8	Water starting to cover Hwy 200 between 1st St and 2nd ST. River well out of banks W, N and E of town and filling old oxbows near town and Hwy 200.
7.5	River out of banks and across highway at Sun River (town). Water over Fairfield Road. River within banks at Simms and Fort Shaw. About two dozen homes in Sun River (town) become isolated.
7	Minor overflow between Fort Shaw and Sun River (town) where the river meanders and gets into the old river bed.
6.5	Some overflow between Fort Shaw and Sun Siver (town) where the river meanders and gets into the old river bed.
6	River is bankfull.
Photos (1) Sun River near Simms looking downstream from highway bridge near gauge house (2) Sun River near Simms looking down at river from bluff

About This Location

Latitude: 47.501628° N, Longitude: 111.931914° W, Horizontal Datum: NAD83/WGS84 River Stage Reference Frame Gauge Height Flood Stage Uses NWS stage 0 ft 7.5 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps Vertical Datum Elevation (gauge height = 0) Elevation (gauge height = flood stage) Elevation information source NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps NGVD 29 Not Available Not Available Older USGS topographic maps, NGVD29 benchmarks MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks Other 3570 ft 3577.5 ft   Current/Historical Observations: U.S. Geological Survey (USGS) Data and Site Info for Simms

Additional Information

Gauge readings available seasonally. Data unavailable during winter months.

Resources

Hydrologic Resources Text Products Past Precipitation Forecast Precipitation River Forecast Centers River Stage Summary MBRFC - Missouri Basin River Forecast Center Upper Missouri Reservoir Inflow Forecasts Milk River Reservoir Inflow Forecasts Water Supply Outlook for the Missouri Basin Great Falls Hydrograph Composite Montana East of Divide Hydrograph Composite Glossary Basin Composites - SNOTEL/Flow/Stage CRREL Map of Current Ice Jams

Additional Resources Area Hydrographs NWS Precipitation and River Forecasting AHPS Iframes for Developers Mobile iNWS for emergency management NWS - Great Falls Home Page USGS - Montana Daily Streamflow Conditions NRCS - Current Snow and Precipitation Data NOHRSC - Snow Information Montana Drought Information NOAA Drought Information Center Montana Ice Jam Awareness Flood Safety Awareness Week March 14-19, 2016 Video: USGS Streamgages - The Silent Superheroes FEMA National Flood Insurance Program

Collaborative Agencies The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here. NWS Information National Weather Service Great Falls Weather Forecast Office 5324 Tri-Hill Frontage Rd Great Falls, MT 59404-4933 (406) 453-2081 Ask Questions/Webmaster Page last modified: 2-Nov-2020 7:28 PM Disclaimer Credits Glossary Privacy Policy About Us Career Opportunities