COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend | ||
| Date/Time (PDT) | Inflow | Date/Time (PDT) | Inflow |
| 2021-06-16 00:00 | 132300 | 2021-06-16 23:00 | 136196.35 |
| 2021-06-15 23:59 | 132300 | 2021-06-17 05:00 | 137020.23 |
| 2021-06-15 00:00 | 138200 | 2021-06-17 11:00 | 136901.73 |
| 2021-06-14 23:59 | 138200 | 2021-06-17 17:00 | 136400.53 |
| 2021-06-14 00:00 | 128100 | 2021-06-17 23:00 | 135813.19 |
| 2021-06-13 23:59 | 128100 | 2021-06-18 05:00 | 135235.75 |
| 2021-06-13 00:00 | 141000 | 2021-06-18 11:00 | 134742.25 |
| 2021-06-12 23:59 | 141000 | 2021-06-18 17:00 | 134322.91 |
| 2021-06-12 00:00 | 144400 | 2021-06-18 23:00 | 133939.44 |
| 2021-06-11 23:59 | 144400 | 2021-06-19 05:00 | 133640.26 |
| 2021-06-11 00:00 | 152800 | 2021-06-19 11:00 | 133536.83 |
| 2021-06-10 23:59 | 152800 | 2021-06-19 17:00 | 133552.47 |
| 2021-06-10 00:00 | 166900 | 2021-06-19 23:00 | 133492.54 |
| 2021-06-09 23:59 | 166900 | 2021-06-20 05:00 | 133355.44 |
| 2021-06-09 00:00 | 170200 | 2021-06-20 11:00 | 133184.13 |
| 2021-06-08 23:59 | 170200 | 2021-06-20 17:00 | 133054.69 |
| 2021-06-08 00:00 | 181100 | 2021-06-20 23:00 | 132927.47 |
| 2021-06-07 23:59 | 181100 | 2021-06-21 05:00 | 132676.35 |
| 2021-06-07 00:00 | 194100 | 2021-06-21 11:00 | 131973.18 |
| 2021-06-06 23:59 | 194100 | 2021-06-21 17:00 | 130372.01 |
| 2021-06-06 00:00 | 190300 | 2021-06-21 23:00 | 128221.83 |
| 2021-06-05 23:59 | 190300 | 2021-06-22 05:00 | 126430.85 |
| 2021-06-22 11:00 | 125154.98 | ||
| 2021-06-22 17:00 | 124173.93 | ||
| 2021-06-22 23:00 | 123355.91 | ||
| 2021-06-23 05:00 | 122623.92 | ||
| 2021-06-23 11:00 | 121936.71 | ||
| 2021-06-23 17:00 | 121290.27 | ||
| 2021-06-23 23:00 | 120641.43 | ||
| 2021-06-24 05:00 | 119928.05 | ||
| 2021-06-24 11:00 | 119123.38 | ||
| 2021-06-24 17:00 | 118259.01 | ||
| 2021-06-24 23:00 | 117350.21 | ||
| 2021-06-25 05:00 | 116399.37 | ||
| 2021-06-25 11:00 | 115425.37 | ||
| 2021-06-25 17:00 | 114471.24 | ||
| 2021-06-25 23:00 | 113537.41 | ||
| 2021-06-26 05:00 | 113092.19 | ||