Extended Streamflow Guidance
Issued by NWS
FGUS65 KSTR 031846
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 3, 2017
The 2017 spring runoff flood potential due to snowmelt is
higher than normal for the Upper Green and Bear River basins in
southwest Wyoming at this time due to much above normal snow conditions
in these areas. However, it should be emphasized that snow typically
accumulates into April and May and the threat of spring flooding will largely
be determined by hydrometeorologic events that occur during the next several
The snow water equivalent in the Upper Green and Bear River basins is much
above normal with many locations near or already having exceeded the annual
peak snowpack which typically occurs in April or May.
Many locations had near to or record precipitation for the month
of January. As result of a wet start to the water year, water year
precipitation (October-January) is much above average
for river basins in southwest Wyoming. Precipitation and
snow conditions as of February 1st are listed below.
PRECIPITATION AND SNOWPACK (% OF AVERAGE):
SUBBASIN JAN OCT-JAN FEB 1 JAN
PRECIP PRECIP SNOW FLOW
---------------------- ------ ------- ----- --------
GREEN ABV FLAMING GORGE 205 170 155 130
BEAR RIVER HEADWATERS 230 165 165 110
The current volume forecasts for the April through July runoff period
are much above average for both the Upper Green and Bear River basins.
Although spring temperatures affect the pattern of snowmelt runoff and
consequently the magnitude of peak flows, peak flows may 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.
The spring runoff flood potential will be re-evaluated in mid February and an updated
product will be issued at that time.