Updated: March 5, 2014
Spring Flood and Water Resource Outlook
This spring flood and water resource outlook is for the North Platte Hydrologic Service Area (HSA), which covers western and north central Nebraska. The river basins include: in the eastern panhandle and western Nebraska, the North and South Platte Rivers and the initial portion of the Platte River; in southwest Nebraska, Frenchman Creek and Stinking Water Creek; in the sandhills of Nebraska, the Loup and Dismal Rivers; and in north central Nebraska, portions of the Elkhorn and Niobrara Rivers.
You can find the Probabalistic Hydrologic Outlook for the North Platte, NE Hydrologic Warning Area here.
Current Flooding and Spring Flood Potential
No flooding is occurring as of March 5, 2014, however recent cold has caused ice jamming on many rivers to bring stages to elevated levels. To obtain the latest watches, warnings, statements, and advisories at any time, go to: http://www.crh.noaa.gov/hazards/lbf.
At this time, chances for flooding over the next several months due to snowmelt is low. However, if further significant snow occurs yet this season the potential for flooding due to snowmelt may change, primarily in small creeks and streams. The flood potential due to ice jams is above average as cold temperatures have cause ice to reform on many area rivers and ice jamming has caused elevated stages in many areas. As warm temperatures return and the ice breaks up, further ice jam flooding is possible. The potential for flooding from reservoir releases is around average. This potential will vary based on the amount of water that is released due to downstream demands later this spring and summer. The potential for rainfall induced flash flooding is not quantifiable, as this type of flooding is most likely to occur during the spring and summer months.
Rivers and streams in the Republican River basin are running well below average, with readings of less than 10 percent of normal. The remainder of rivers and streams across western and north central Nebraska are observing near or above average streamflows. The rivers and streams with the higher flows are primarily due to increased runoff from recently melted snow and ice, however many are being impacted by ice at the current time. Below is a map showing how the current streamflow compares to historical streamflows with blue colors signifying above normal conditions, green colors meaning near normal, and oranges and reds being below normal. Click on the image to go to the USGS webpage for specifics on streamflow in your area.
Image courtesy of the USGS
Ground water levels vary across western and north central Nebraska. Below normal ground water depths are being observed across southwest Nebraska, while near normal depths are being observed for much of the remainder of the area. Where the ground water depths are lowest, sites were reporting levels at or below 25 percent of normal. The graphic below links to groundwater depth information courtesy of the USGS.
Image courtesy of the USGS
Mountain Snowpack and Inflows into the North and South Platte Rivers
As of early March, snowpack in the source regions of the North and South Platte Rivers above normal. In the North Platte River basin, snow water equivalent averaged near 125 percent of normal, while snow water equivalent in the South Platte River basin averaged near 135 percent of normal.
Although mountain snowpack is above normal, reservoirs along the North Platte River have storage available and can take in the increased snowmelt runoff to keep flood potential near normal. However, there does remain chances for flooding due to reservoir releases downstream of Lake McConaughy this spring and early summer, which will depend on demands downstream.
Along the South Platte River, with current flows and mountain snowpack both above normal, chances for snowmelt runoff flooding are slightly above normal.
NRCS data: Plot courtesy of the University of Wyoming
Snow Cover and Liquid Water Content
Snow cover across western and north central Nebraska varies as of March 5th, from 0 to 6 inches. The deeper snow is across northern Nebraska, in the Niobrara and Elkhorn River basins. Other areas have minimal snow cover.
Since October 1, 2013, precipitation has been near or slightly below average for much of western and north central Nebraska. The exception is across the far northern parts of Nebraska into the panhandle, from northern Cherry County into Sheridan County, where higher precipitation fell in October to bring amounts for the season above average. Also, locations from southwest Nebraska into the panhandle, from Chase County into Deuel and Garden counties saw above normal snow in February, with some places measuring above 20 inches.
According to the U.S. Drought Monitor, drought conditions have improved for much of western and north central Nebraska. However much of the area does continue to observe severe to extreme drought conditions, which is ongoing from October of 2012.
Specifically, moderate to extreme drought conditions were occurring roughtly south of Highway 20 from Ewing to Hay Springs. Areas south of Highway 2 from Antioch to Dunning, and west from Dunning to Eustis were experiencing severe to extreme drought conditions. Extreme drought continued across western Frontier, Hayes, southwestern Lincoln, eastern Perkins, and eastern Chase counties. North of Highway 20, no drought conditions were occurring.
Image courtesy of the US Drought Monitor
Soil Conditions and Frost Depths
According to the US Drought Monitor, soil moisture varies across western and north central Nebraska, from well below normal across southwest Nebraska in the Republican River basin to slightly above normal in the Niobrara River basin. The remainder of the area is observing near normal soil moisture.
Recent cold weather has caused frost depths to increase, with readings across the area of 6 to 12 inches.
Current Reservoir Data along the North Platte River
Normal operations are ongoing at area dams and reservoirs along the North Platte River for this time of year. With little or no flows coming from these reservoirs, levels have stayed fairly steady or saw slight rises through the winter season.
Lake McConaughy Elevation over the past Month
Current Reservoir Data for the Wyoming Reservoir System
|Seminoe Reservoir||Pathfinder Reservoir|
|Glendo Reservoir||Guernsey Reservoir|
courtesy of the Bureau of Reclamation
Precipitation and Temperature Outlook
According to the Climate Prediction Center, the 8 to 14 day outlook for western and north central Nebraska indicates equal chances for below, near, or above normal temperatures and for and higher chances for above normal precipitation for southwest Nebraska and equal chances for below, near, or above normal precipitation for the remainder of western and north central Nebraska.
|8 to 14 day Temperature Outlook||8 to 14 day Precipitation Outlook|
The three month outlook for March, April, and May indicates equal chances of above, near, or below normal for both temperature and precipitation.
Three Month Temperature Outlook
Three Month Precipitation Outlook
Questions or Comments
If you have questions or comments about this spring flood and water resource outlook please contact:
Hydrologic Program Leader
National Weather Service
5250 E. Lee Bird Drive
North Platte, NE 69101