Frost depth data shown in this map is queried from the North Central River Forecast Center (NCRFC) database late morning each day. Frost depth reports here are commonly from frost tube instruments, visual reports from construction or cemetery sites, or other types of electronic probes. Frost conditions are an important factor for hydrologic forecasting as frozen soil limits infiltration of water thereby generating more runoff from rain and snowmelt than soil that is not frozen. Knowing soil frost condition is also important for many activities including agriculture, horticulture, transportation, construction, and even grave digging.

Map of all sites that report frost depth or have reported frost depth in the past, for which there is data in the Missouri Basin River Forecast Center database. Frost depth reports here are commonly from frost tube instruments, visual reports from construction or cemetery sites, or other types of electronic probes. Frost conditions are an important factor for hydrologic forecasting as frozen soil limits infiltration of water thereby generating more runoff from rain and snowmelt than soil that is not frozen. Knowing soil frost condition is also important for many activities including agriculture, horticulture, transportation, construction, and even grave digging.

This Web Map is created to support the 2024 Spring Flood Outlook interactive StoryMap that can be found here: https://storymaps.arcgis.com/stories/895e74ed32b24342a96483c4e852c867. The spring flood risks portrayed in this map are explained in the National Hydrologic Assessment issued by the National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS) on March 21, 2024 (https://www.weather.gov/owp/2024NHA). This map shows the basins with a 50% or more likelihood of exceeding minor, moderate, and major flood levels during April through June, 2024. The National Hydrologic Assessment offers an analysis of flood risk and water supply for Spring 2024 based on late summer, fall, and winter precipitation, frost depth, soil saturation levels, snowpack, current streamflow, and projected spring weather. NOAA's network of 122 Weather Forecast Offices, 13 River Forecast Centers, National Water Center, and other national centers nationwide assess this risk and summarize at the national scale. The 2024 NOAA National Spring Flood Outlook Dataset is generated using the "Long-Range River Flood Risk" for approximately 2,600 river and stream forecast locations across the nation for this spring provided by the National Weather Service. The "Long-Range River Flood Risk" from the river and stream forecast locations are then extrapolated to a basin scale using the Watershed Boundary Dataset (WBD)'s hydrologic unit codes (HUC) provided by the USDA-NRCS, USGS, and EPA. The current "Long Range River Flood Risk" is available at: https://water.weather.gov/ahps/long_range.php. Using the "Long Range River Flood Risk", stakeholders can access a single, nationally consistent map depicting the 3-month risk of minor, moderate, and major river flooding. This risk information is based on NOAA's Ensemble Streamflow Prediction (ESP) forecasts which are generated for approximately 2,600 river and stream forecast locations across the nation. With this capability, stakeholders can quickly view flood risk predicted to affect their specific area of concern.The Long-Range River Flood Risk improves the value of the National Hydrologic Assessment by clearly and objectively communicating flood risk at the local level. The National Weather Service (NWS), in coordination with local officials, defines flood levels for each of its river forecast locations, based on the impact over a given area. The flood categories are defined as follows:Minor Flooding: Minimal or no property damage, but possibly some public threat (e.g., inundation of roads).Moderate Flooding: Some inundation of structures and roads near the stream. Some evacuations of people and/or transfer of property to higher elevations.Major Flooding: Extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.

The 2021 National Hydrologic Assessment offers an analysis of flood risk, water supply, and ice break-up and jam flooding for spring 2021 based on late summer, fall, and winter precipitation, frost depth, soil saturation levels, snowpack, current streamflow, and projected spring weather. NOAA's network of 122 Weather Forecast Offices, 13 River Forecast Centers, National Water Center, and other national centers nationwide assess this risk, summarized here at the national scale. Overall, a reduced risk of spring flooding exists this year primarily due to a mainly dry fall and winter, along with limited snow still remaining on the ground. Major flooding is not expected this spring season. Minor to moderate flooding is ongoing across portions of the Lower Missouri River Basin with the flood risk predicted to continue through spring. The exception to the reduced risk is over the Coastal Plain of the Carolinas and Lower Ohio River Basin where flooding is predicted this spring, driven by above normal precipitation over the winter months, which has led to ongoing flooding, elevated streamflows, and highly saturated soil conditions. This wet pattern is expected to continue across the Coastal Plain of the Carolinas and Lower Ohio River Basin through spring, making these regions vulnerable to spring flooding. It is important to note that heavy rainfall at any time can lead to flooding, even in areas where overall risk is considered low. This assessment addresses only spring flood potential on the timescale of weeks to months, not days or hours. Debris flow and flash flooding often associated with burn scars and urban areas can form quickly and occur any time with heavy rainfall events. Nearly every day, flooding happens somewhere in the United States or its territories. Flooding can cause more damage than any other weather-related event...with an annual average direct damage impact of 8 billion dollars a year over the past 40 years, with these impact costs adjusted for inflation. Flooding is one of America's most underrated killers, causing nearly 100 fatalities per year… roughly half of which occur in vehicles. Flowing water can be particularly powerful and dangerous… with just six inches of water able to sweep a person off their feet… and two feet of rushing water able to carry a mid-size car downstream. No vehicle should ever attempt to cross a flooded roadway, and drivers are reminded to “Turn Around, Don’t Drown.” To be prepared, every American should know their flood risk and what to do before, during, and after a flood event. This information is available at www.ready.gov/floods. To remain apprised of your current flood risk, visit weather.gov for the latest official watches and warnings. For detailed hydrologic conditions and forecasts, go to water.weather.gov.

This Web Map is created to support the 2025 Spring Flood Outlook interactive StoryMap that can be found here: https://storymaps.arcgis.com/stories/2b8a69e27501414bbbe1a4befeb00ddb. The spring flood risks portrayed in this map are explained in the National Hydrologic Assessment issued by the National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS) on March 20, 2025 (https://www.weather.gov/owp/2025NHA). This map shows the basins with a 50% or more likelihood of exceeding significant flooding (defined as moderate and major flood levels) during April through June, 2025. The National Hydrologic Assessment offers an analysis of flood risk and water supply for Spring 2024 based on late summer, fall, and winter precipitation, frost depth, soil saturation levels, snowpack, current streamflow, and projected spring weather. NOAA's network of 122 Weather Forecast Offices, 13 River Forecast Centers, National Water Center, and other national centers nationwide assess this risk and summarize at the national scale. The 2025 NOAA National Spring Flood Outlook Dataset is generated using the "Long-Range River Flood Risk" for approximately 2,600 river and stream forecast locations across the nation for this spring provided by the National Weather Service. The "Long-Range River Flood Risk" from the river and stream forecast locations are then extrapolated to a basin scale using the Watershed Boundary Dataset (WBD)'s hydrologic unit codes (HUC) provided by the USDA-NRCS, USGS, and EPA. The current "Long Range River Flood Risk" is available at: https://water.noaa.gov. Using the "Long Range River Flood Risk", stakeholders can access a single, nationally consistent map depicting the 3-month risk of minor, moderate, and major river flooding. This risk information is based on NOAA's Ensemble Streamflow Prediction (ESP) forecasts which are generated for approximately 2,600 river and stream forecast locations across the nation. With this capability, stakeholders can quickly view flood risk predicted to affect their specific area of concern.The Long-Range River Flood Risk improves the value of the National Hydrologic Assessment by clearly and objectively communicating flood risk at the local level. The National Weather Service (NWS), in coordination with local officials, defines flood levels for each of its river forecast locations, based on the impact over a given area. The flood categories are defined as follows:Minor Flooding: Minimal or no property damage, but possibly some public threat (e.g., inundation of roads).Moderate Flooding: Some inundation of structures and roads near the stream. Some evacuations of people and/or transfer of property to higher elevations.Major Flooding: Extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.