FGUS65 KSTR 081459 ESGWY COLORADO BASIN RIVER FORECAST CENTER NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH SPRING FLOOD POTENTIAL FOR THE GREEN AND BEAR RIVER BASINS IN WYOMING MARCH 8, 2023 The 2023 spring runoff flood potential due to snowmelt is not high at this time in the Upper Green River and Bear River Basins of southwest Wyoming. Spring peak flows due to snowmelt are expected to be near to slightly above average in the Bear River Basin and below average in the Upper Green River Basin at this time. It should be emphasized that there is still time for significant snow accumulation in March and Apil, and conditions could change before runoff begins. Currently, the following sites are forecast to have mean daily peak flows at or above the listed threshold at the given exceedance level: Segment Threshold Exceedance Value (probability) ------- -------- ------------- Bear-Utah-Wyoming State Line Bankfull 90 Bear-Evanston Bankfull 50 Bear-Border Flood 25 Green-La Barge Bankfull 50 Green-Green River,Wy Bankfull 25 Precipitation in the Bear River Basin was above average during February and is also above average for the water year (October-February) total; March 1 snow water equivalent was much above median. Precipitation in the Upper Green River Basin was near average during February and is also near average for the water year total; March 1 snow water equivalent was above median. PRECIPITATION(% OF AVERAGE) AND SNOWPACK (% OF MEDIAN): SUBBASIN FEB OCT-FEB MAR 1 PRECIP PRECIP SNOW ---------------------- ------ ------- ----- GREEN ABV FLAMING GORGE 95 105 115 BEAR RIVER HEADWATERS 130 125 150 The current volume forecasts for the April thorugh July runoff period are near to above average in the Bear, ranging between 103 and 114% of average, while forecasts in the Upper Green are near to below average and range from 78 to 106% of average. 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: http://www.cbrfc.noaa.gov/rmap/peak/peaklist.php A map of the current spring peak flow forecasts is available at: http://www.cbrfc.noaa.gov/lmap/lmap.php?interface=peak The spring runoff flood potential will be re-evaulated in mid March and an updated product will be issued at that time. CBRFC/Alcorn,Kormos