Extended Streamflow Guidance
Issued by NWS
FGUS65 KSTR 171856
COLORADO BASIN RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH
SPRING FLOOD POTENTIAL
FOR THE GREEN AND BEAR RIVER BASINS IN WYOMING
FEBRUARY 17, 2015
The 2015 spring runoff flood potential due to snowmelt is
is not high this time for the Upper Green and Bear River
basins. However, it should be emphasized that it is still
early in the snow accumulation season and conditions could
change before the runoff begins.
January precipitation was much below average in all basins across
southwest Wyoming with values ranging from 45 to 55 percent of average.
Seasonal precipitation is slightly below average in both the
Upper Green above Flaming Gorge and Bear River basins.
However, seasonal precipitation is near normal in headwater
areas above Fontenelle reservoir.
Month to date precipitation for the month of February has been near average in
the Green River basin above Fontenelle and below average for all other basins
in southwest Wyoming. February 17th snow water equivalent is 125% of median
above Fontenelle reservoir,110% of median above Flaming Gorge reservoir,
and 63% of median in the headwaters of the Bear River.
Although spring temperatures affect the pattern of snowmelt runoff and
consequently the magnitude of peak flows, peak flows also roughly correspond
to volumetric flows. Current model guidance for April-July runoff
volumes has decreased since the forecasts were issued
at the beginning of February and are near or below average.
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, regardless of snowpack conditions.
The spring runoff flood potential will be re-evaluated in early March
and an updated product will be issued at that time.