1. Missouri River Basin Forecast Brian Anderson Wyoming Area Office Meeting, January 20, 2010

2. Forecast Use the most recent 30 year data for statistical regression Use average future rainfall

3. Snotel Stations Used For Buffalo Bill Snowmelt Runoff Forecast

4. Snow Water Equivalent as of Jan 6, 2010

5. SNOW WATER EQUIVALENT AS PERCENT OF AVERAGE Natural Resources Conservation Service - Monday MORNING SNOW REPORT (No. 11) January 4, 2010 DRAINAGE BASIN1/4/201012/28/200912/21/20091/4/200912/28/2008 SNAKE RIVER 61576310186 UPPER YELLOWSTONE 73748010084 WIND RIVER 7981878688 BIGHORN BASIN 73757810390 SHOSHONE 7071769975 POWDER - TONGUE 828687114110 BELLE FOURCHE 10211373116130 UPPER NORTH PLATTE 9289938993 LOWER N PLATTE,SWT 97102 7577 LITTLE SNAKE RIVER 9287919397 UPPER GREEN RIVER 5150579379 LOWER GREEN RIVER 6465696466 UPPER BEAR RIVER 5961658589 Weighted State Average7880819389

6. Forecast Input Data The forecast program for Buffalo Bill was developed about 15 years ago and uses a multiple linear correlation routine to determine a best fit solution.

7. Forecast Output

8. Water Year April-July Inflow (acre-feet) 2007426,500 2008955,300 2009954,200 2010??? Average = 659,700 Basin above Buffalo Bill Reservoir Snow Water Equivalent

9. Precipitation Outlook - Apr, May, June 2010

11. Buffalo Bill Reservoir Water Supply Forecast January 1 Forecast of April – July Snowmelt Runoff

12. Water Year JanuaryFebruaryMarchAprilMayJune Actual Inflow 2000500,000540,000550,000 500,000 536,200 2001500,000430,000400,000375,000400,000360,000374,800 2002550,000 490,000500,000550,000530,000552,500 2003500,000550,000 650,000560,000540,000667,900 2004630,000530,000 400,000350,000400,000387,000 2005500,000450,000425,000400,000 485,000513,400 2006600,000650,000 600,000500,000470,000545,900 2007500,000 525,000425,000 410,000426,500 2008600,000 680,000720,000875,000955,300 2009630,000700,000650,000700,000750,000720,000954,200 Buffalo Bill Reservoir Forecasted April-July Inflow (acre-feet) The April forecast has been within 10% of actual inflow in 6 of the past 10 years.

13. Annual average 15.80 inches 2009 cumulative total 16.45

14. Operation Minimum, Maximum and Expected

17. Buffalo Bill Dam, Visitor Center, & Shoshone Powerplant