SLCESPAZ NATIONAL WEATHER SERVICE COLORADO BASIN RIVER FORECAST CENTER SALT LAKE CITY, UTAH June 17, 2019 The following are updated forecasts for the Lake Mead Local (or intervening flow). Forecasts include monthly values for June - August. ------------------------------------------------------------------- June 1-16 OBSERVED (EST.) DATA: (From USGS gage data) - values in KAF - (Colorado Diamond Ck 444.3 + Muddy River 1.2 + Virgin River 21.8 - BOR Powell Release 404.0) ~ 63.3 KAF ------------------------------------------------------------------- FORECASTS (using the Ensemble Prediction System): * All Forecasts are the 50% exceedance probability value * Lake Mead Intervening Flow: June - August Forecasts June 85 KAF (137% of average) July 63 KAF (100% of average) August 90 KAF (100% of average) Lake Mead Adjusted Intervening Flow: June - August Forecasts June 64.4 KAF July 64.1 KAF August 101.8 KAF Equation Used for Adjusted Flow: Inflow(BOR) = Inflow(NWS) + Evap(BOR) - Evap(NWS) + BankStorageChange(BOR) ------------------------------------------------------------------- Tributaries: Virgin River nr Littlefield Jun 26.9 KAF (583% of median or 263% of average) Jul 7.1 KAF (122% of median or 100% of average) Aug 9.1 KAF (117% of median or 100% of average) Little Colorado nr Cameron Jun 0.1 KAF (1000% of median or 56% of average) Jul 6.3 KAF ( 256% of median or 100% of average) Aug 19.3 KAF ( 186% of median or 100% of average) Paria Creek nr Lees Ferry Jun 0.9 KAF (318% of median or 203% of average) Jul 1.0 KAF (151% of median or 101% of average) Aug 2.4 KAF (110% of median or 100% of average) * All Forecasts are the 50% exceedance probability value * $$ Finch/CBRFC