SLCESGUT Apr, 2023
Download http://www.cbrfc.noaa.gov/product/oup/text/SLCESGUT/SLCESGUT.1680898175.006
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FGUS65 KSTR 072008
ESGUT
NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UT
April 6, 2023
SPRING FLOOD POTENTIAL OUTLOOK
UTAH
Great Salt Lake, Sevier, Virgin, Price/San Rafael, Duchesne and Lower Green
River Basins.
The 2023 spring runoff flood potential due to snowmelt is high at
this time for all major river basins in Utah due to near record
or record snowpack. These basins include the Bear, Weber, Provo,
Six Creeks,Duchesne,Sevier,Virgin,Price/San Rafael,and Green River
basins. It should be emphasized that snow typically accumulates into
April,therefore conditions may change before the runoff begins.
Currently, the following sites are forecast to have mean daily peak flows
at or above the defined flood flow at the given exceedance level:
Segment Threshold Exceedance Value
(probability)
------- -------- -------------
Blacks Fk-Robertson Flood 10
Green-Jensen Flood 50
Green-Green River UT Flood 25
Duchesne - Tabiona Flood 25
Bear-Utah-Wyoming State Line Bankfull 90
Bear-Evanston Flood 10
Bear-Border Flood 90
Logan-Logan Flood 25
Little Bear-Paradise Flood 90
Blacksmith Fork-Hyrum Flood 10
Weber-Oakley Flood 25
Chalk Ck-Coalville Flood 25
Mcleod Ck-Park City Flood 25
Provo-Woodland Flood 10
Little Cottonwood-SLC Flood 50
Big Cottonwood-SLC Flood 90
Mill Ck-SLC Flood 25
Emigration Ck-SLC Flood 50
City CK-Salt Lake City Flood 90
Sevier-Hatch Flood 50
Specific forecast procedures and flood flow levels do not exist for all streams.
Areas that typically experience high water in normal or above
normal snow years will be susceptible during peak runoff this year. Instantaneous
peaks can be higher than mean daily peaks, especially in headwater basins.
Precipitation for all major river basins in Utah was much above average for March
and is also much above average for the water year. April 1 snow water equivalent is
much above median with many basins having record or near record snow conditions.
Temperatures have remained below normal limiting any significant snowmelt which
has resulted in much above normal snow conditions at all elevations.
PRECIPITATION (% OF AVERAGE) AND SNOWPACK (% OF MEDIAN):
SUBBASIN MAR PRECIP OCT-MAR PREC APR 1 SNOWPACK
---------------------- ---------- ------------ -------------
BEAR 205 135 175
WEBER 230 150 220
SIX CREEKS (SLC) 255 160 230
PROVO 245 160 250
SEVIER 195 150 225
VIRGIN 210 170 400
DUCHESNE 210 140 200
PRICE/SAN RAFAEL 220 150 245
Spring temperatures and rain events greatly affect the pattern of snowmelt
runoff and consequently the magnitude of peak flows. It is 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.
A list of specific spring peak flow forecasts is available at:
https://www.cbrfc.noaa.gov/dbdata/station/peakgraph/list/peaklist.html?type=rank
A map of the current spring peak flow forecasts is available at:
https://www.cbrfc.noaa.gov/lmap/lmap.php?interface=peakfp
The spring runoff flood potential will be re-evaulated in mid April and
an updated product will be issued at that time.
CBRFC/P.Kormos, B.Alcorn, T.Grout