COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-09-19 09:48 PDT | ||
| Date/Time (PDT) | Inflow | Date/Time (PDT) | Inflow |
| 2026-09-19 00:00 | 70500 | 2026-09-19 17:00 | 70490.5 |
| 2026-09-18 00:00 | 63800 | 2026-09-19 23:00 | 71136.19 |
| 2026-09-17 00:00 | 62800 | 2026-09-20 05:00 | 72011.9 |
| 2026-09-16 00:00 | 69100 | 2026-09-20 11:00 | 72952.22 |
| 2026-09-15 00:00 | 73500 | 2026-09-20 17:00 | 73811.79 |
| 2026-09-14 00:00 | 61300 | 2026-09-20 23:00 | 74460.98 |
| 2026-09-13 00:00 | 74500 | 2026-09-21 05:00 | 74871.38 |
| 2026-09-12 00:00 | 69700 | 2026-09-21 11:00 | 75128.33 |
| 2026-09-11 00:00 | 68000 | 2026-09-21 17:00 | 75328.87 |
| 2026-09-10 00:00 | 65000 | 2026-09-21 23:00 | 75416.39 |
| 2026-09-09 00:00 | 63300 | 2026-09-22 05:00 | 75401.01 |
| 2026-09-22 11:00 | 75355.84 | ||
| 2026-09-22 17:00 | 75304.06 | ||
| 2026-09-22 23:00 | 75248.45 | ||
| 2026-09-23 05:00 | 75191.26 | ||
| 2026-09-23 11:00 | 75133.84 | ||
| 2026-09-23 17:00 | 75079.28 | ||
| 2026-09-23 23:00 | 75022.72 | ||
| 2026-09-24 05:00 | 74966.12 | ||
| 2026-09-24 11:00 | 74910.89 | ||
| 2026-09-24 17:00 | 74858.03 | ||
| 2026-09-24 23:00 | 74805.5 | ||
| 2026-09-25 05:00 | 74753.24 | ||
| 2026-09-25 11:00 | 74702.04 | ||
| 2026-09-25 17:00 | 74653.31 | ||
| 2026-09-25 23:00 | 74603.17 | ||
| 2026-09-26 05:00 | 74244.4 | ||
| 2026-09-26 11:00 | 72898.6 | ||
| 2026-09-26 17:00 | 70772.78 | ||
| 2026-09-26 23:00 | 69132.29 | ||
| 2026-09-27 05:00 | 68482.81 | ||
| 2026-09-27 11:00 | 68322.68 | ||
| 2026-09-27 17:00 | 68259.22 | ||
| 2026-09-27 23:00 | 68207.11 | ||
| 2026-09-28 05:00 | 68167.59 | ||
| 2026-09-28 11:00 | 68186.56 | ||
| 2026-09-28 17:00 | 68344.85 | ||
| 2026-09-28 23:00 | 68691.53 | ||
| 2026-09-29 05:00 | 69159.41 | ||