SLCESPAZ NATIONAL WEATHER SERVICE COLORADO BASIN RIVER FORECAST CENTER SALT LAKE CITY, UTAH July 1, 2019 The following are updated forecasts for the Lake Mead Local (or intervening flow). Forecasts include monthly values for July - September. ------------------------------------------------------------------- June 1-30 OBSERVED (EST.) DATA: (From USGS gage data) - values in KAF - (Colorado Diamond Ck 837.2 + Muddy River 2.2 + Virgin River 21.1 - BOR Powell Release 768.8) ~ 91.7 KAF ------------------------------------------------------------------- FORECASTS (using the Ensemble Prediction System): * All Forecasts are the 50% exceedance probability value * Lake Mead Intervening Flow: July - September Forecasts July 63 KAF (100% of average) August 90 KAF (100% of average) September 76 KAF (100% of average) Lake Mead Adjusted Intervening Flow: July - September Forecasts July 59.1 KAF August 101.8 KAF September 68.9 KAF Equation Used for Adjusted Flow: Inflow(BOR) = Inflow(NWS) + Evap(BOR) - Evap(NWS) + BankStorageChange(BOR) ------------------------------------------------------------------- Tributaries: Virgin River nr Littlefield Jul 7.1 KAF (122% of median or 100% of average) Aug 9.1 KAF (117% of median or 100% of average) Sep 9.7 KAF (130% of median or 100% of average) Little Colorado nr Cameron Jul 6.3 KAF (256% of median or 100% of average) Aug 19.3 KAF (186% of median or 100% of average) Sep 13.9 KAF (118% of median or 100% of average) Paria Creek nr Lees Ferry Jul 1.0 KAF (151% of median or 101% of average) Aug 2.4 KAF (110% of median or 100% of average) Sep 2.4 KAF (162% of median or 101% of average) * All Forecasts are the 50% exceedance probability value * $$ Finch/CBRFC