Extended Streamflow Guidance
Issued by NWS
FGUS65 KSTR 061805
National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
January 6, 2017
FLOOD POTENTIAL OUTLOOK
Great Salt Lake, Sevier, Virgin and Price/San Rafael and Duchesne
The 2017 spring runoff flood potential due to snowmelt is elevated at
this time for the Bear, Weber, Provo, Duchesne river basins.
December precipitation values were 145-170 percent of average. Snowpacks in Utah
are much above average and range from 145-215 percent of average across the state.
Much above average precipitation and below average temperature resulted in large
early season snowpack which will impact flood potential if temperatures rise
rapidly as the January 1st volumetric forecast are above average.
It should be emphasized that snow accumulation conditions could change quite a
bit before the runoff begins. Although spring temperatures affect the pattern of
snowmelt runoff and consequently the magnitude of peak flows, peak flows also
roughly correspond to volumetric flows. It is also important to keep in mind that
an extended period of much above normal temperatures or heavy rainfall during the
melt period can cause or exacerbate flooding problems in any year.
CBRFC/B.Bernard, A.Nielson, T. Cox