Extended Streamflow Guidance
Issued by NWS
FGUS65 KSTR 042125
National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
March 4, 2015
FLOOD POTENTIAL OUTLOOK
The 2015 spring runoff flood potential due to snowmelt is not high at this time
for the Great Basin, as well as the Sevier, Virgin, Price/San Rafael, and the
Duchesne River Basins.
Current snowpack conditions in the above basins are below average. Current
seasonal snowpack conditions as a percent of median are:
Virgin River Basin 60%
Sevier River Basin 70%
Price/San Rafael River Basin 65%
Duchesne River Basin 65%
--Bear River Basin 85%
--Weber River Basin 65%
--Six Creeks Basin 65%
--Utah Lake 60%
Currently, the following sites are forecast to peak at or above the bankfull
flow at the given exceedance level:
Bear River at Evanston, WY 10%
No sites are currently forecasted to reach flood stage at this time.
Specific forecast procedures and flood flow levels do not exist for all streams.
Given current snowpack conditions, below average to near average peaks may be
anticipated throughout the state
Current volume forecasts for the April through July runoff period are below
average to near average for much of the state. In particular, volume forecasts
in the southern portion of the state and Great Basin are well below average.
It should be emphasized that snow conditions could change
significantly before seasonal runoff begins. While spring temperatures
affect the pattern of snowmelt runoff and, consequently, the magnitude of peak
flows, peak flows also approximately correspond to volumetric flows. It is also
important to recognize that an extended period of much above average temperatures
or heavy rainfall during the melt period can cause or exacerbate flooding
problems in any year.
A list of specific spring peak flow forecasts are available at:
A map of the current spring peak flow forecasts is available at:
CBRFC/W.P. Miller, A.Nielson, T. Cox