1. Upper Snake Reservoir Operations October 13, 2015
Henry’s Fork Watershed Council
Upper Snake Reservoir Operations
October 13, 2015

2. 41% of Capacity

3. 88% of Capacity

4. 29% of Capacity

5. Coordinated Forecast Month-July Snake River nr Heise, ID
January Forecast 109% (4,130 KAF)
78% of Average Precipitation
February Forecast 101% (3,625 KAF)
77% of Average Precipitation
March Forecast 95% (3,256 KAF)
41% of Average Precipitation
April Forecast 78% (2,515 KAF)
59% of Average Precipitation
May Forecast 63% (1,800 KAF)
136% of Average Precipitation

6. 2015 Water Year-to-Date Precipitation

7. WY2015 Percent 30yr Avg. Runoff
Snake River nr Heise, ID
April-July Forecast 78% (2,515 KAF)
April-July Observed 85% (2,740 KAF)
WY2015 Observed 91% (4,530 KAF)
Henrys Fork nr Island Park, ID
April-July Forecast 47% (102 KAF)
April-July Observed 59% (127 KAF)
WY2015 Observed Runoff 68% (319 KAF)

16. 2016 Temperature Outlook

17. 2016 Precipitation Outlook

21. Conclusions System carryover is lower than in 2014 but good overall
Good probability of high system storage for 2016 allocations
Minimum winter flows at most facilities
Not expected to change unless flood control operations are needed
Current winter forecasts lack confidence
Abnormal ocean temperatures
Long-lead forecast uncertainty