1. Intervening flow forecasts (inflow between Lake Mead and Lake Powell) Inflow forecasts needs between Davis & Parker – Havasu operational limits Forecast needs below Havasu to Imperial Dam Precipitation forecasts for irrigators (Imperial Valley) Forecast ability for inflow between Davis and Parker ? Requirement / ability to model downstream to Imperial Dam. Availability of projected releases from Reclamation for Mead, Havasu, and Mohave. Identify relevant rainfall that might affect Imperial Valley irrigation (WFO Chat). Determine the best number to represent upper basin SWE % of average. Communicate differences in Powell to Mead intervening flow means to Reclamation group in Boulder, CO for further discussion Assist CBRFC in determining what diversions/data exist downstream of Mohave applicable to future modeling efforts. Review possibility of funding streamflow gages on the Sacrament and Piute washes including adding additional precipitation gages in these areas. Coordinate with WFO Las Vegas for NWS Chat access ? CBRFC-Lower Reclamation Primary Forecast Issues: Outstanding CBRFC Action Items: Outstanding Reclamation Action Items: Lower Colorado Basin – USBR Items

2. Intervening Flow Forecasts: Lake Powell to Lake Mead Colorado River - Lake Powell to Diamond Fork Little Colorado Paria River Virgin River Muddy Creek Annual Distribution Inflow between Powell & Mead NWSRFS Modeled River Segments Best Skill

3. Lake Mead Intervening Flow – 2010 Forecasts & Observed

4. Forecast Calculations: Colorado @ Diamond Ck (CDCA3) + Virgin above Overton (VLMN2) + Muddy near Glendale (MUDN2) – Colorado @ Lee’s Ferry (CLFA3) Lake Mead Inflow (LKSA3) – Colorado @ Lee’s Ferry (CLFA3) LKSA3 = CDCA3 + MUDN2 + VLTA3 – CLFA3 + local flow Observed Calculation: Colorado @ Diamond Ck (CDCA3) + Virgin above Overton (VLMN2) + Muddy near Glendale (MUDN2) – Colorado @ Lee’s Ferry (CLFA3) 48 43 57 65 79 89 98 98 90 80 69 59.36.33.37.46.53.64.80.85.70.51.51.44 CBRFC monthly evaporation (KAF) Jan-Dec Reclamation monthly evaporation coefficients (feet) Jan-Dec Coefficients are multiplied by the average surface area of Lake Mead over the course of a month. CBRFC Evaporation = CDCA3 + MUDN2 + VLMN2 – Change in Storage – Release – Las Vegas Wash + Southern Nevada Waste Water Diversion

5. Lake Havasu Local Inflow NWSRFS Modeled River Segments Calibration System: Challenges: Finding significant precipitation events during the calibration period (signal to noise ratio) Possible Solutions : Expand Precipitation gages on California side Increase density of precipitation gages Rate current Mojave County streamflow gages Installation of streamflow gages on major washes between Davis and Parker Dams  Sacramento Wash (largest)  Piute Wash

6. Lake Havasu Local Inflow NWSRFS Modeled River Segments Primary Inputs  Observed river stage & reservoir release data  Observed Hourly Data Gage data (Mojave Co. ALERT) NWS Doppler Radar  Forecast Precipitation 6 Hourly QPF Data Operational Forecast System: Additional Operational Data Needs Release schedule or pattern for reservoirs