COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-04-27 16:07 PDT | ||
| Date/Time (PDT) | Inflow | Date/Time (PDT) | Inflow |
| 2026-04-27 00:00 | 137600 | 2026-04-27 23:00 | 135900.83 |
| 2026-04-26 00:00 | 134200 | 2026-04-28 05:00 | 135091.72 |
| 2026-04-25 00:00 | 140700 | 2026-04-28 11:00 | 133731.12 |
| 2026-04-24 00:00 | 133100 | 2026-04-28 17:00 | 131957.58 |
| 2026-04-23 00:00 | 128700 | 2026-04-28 23:00 | 131242.87 |
| 2026-04-22 00:00 | 124200 | 2026-04-29 05:00 | 130889.88 |
| 2026-04-21 00:00 | 124900 | 2026-04-29 11:00 | 130541.24 |
| 2026-04-20 00:00 | 125100 | 2026-04-29 17:00 | 130224.98 |
| 2026-04-19 00:00 | 121000 | 2026-04-29 23:00 | 129956.41 |
| 2026-04-18 00:00 | 122900 | 2026-04-30 05:00 | 129697.24 |
| 2026-04-17 00:00 | 117900 | 2026-04-30 11:00 | 129449.86 |
| 2026-04-30 17:00 | 129292.83 | ||
| 2026-04-30 23:00 | 129287.52 | ||
| 2026-05-01 05:00 | 129355.96 | ||
| 2026-05-01 11:00 | 129487.93 | ||
| 2026-05-01 17:00 | 129740.91 | ||
| 2026-05-01 23:00 | 130107.56 | ||
| 2026-05-02 05:00 | 130499.01 | ||
| 2026-05-02 11:00 | 130878.62 | ||
| 2026-05-02 17:00 | 131291.58 | ||
| 2026-05-02 23:00 | 131740.02 | ||
| 2026-05-03 05:00 | 132170.27 | ||
| 2026-05-03 11:00 | 132573.62 | ||
| 2026-05-03 17:00 | 132986.5 | ||
| 2026-05-03 23:00 | 133390.09 | ||
| 2026-05-04 05:00 | 133736.43 | ||
| 2026-05-04 11:00 | 134049 | ||
| 2026-05-04 17:00 | 134395.72 | ||
| 2026-05-04 23:00 | 134777.98 | ||
| 2026-05-05 05:00 | 135161.42 | ||
| 2026-05-05 11:00 | 135592.36 | ||
| 2026-05-05 17:00 | 136170.84 | ||
| 2026-05-05 23:00 | 136912.26 | ||
| 2026-05-06 05:00 | 137763.85 | ||
| 2026-05-06 11:00 | 138708.13 | ||
| 2026-05-06 17:00 | 139728.85 | ||
| 2026-05-06 23:00 | 140751.63 | ||
| 2026-05-07 05:00 | 141693.95 | ||