COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-11-04 08:00 PST | ||
| Date/Time (PST) | Pool Height | Date/Time (PST) | Pool Height |
| 2026-11-04 00:00 | 1289.12 | 2026-11-04 10:00 | 1289.02 |
| 2026-11-03 00:00 | 1288.93 | 2026-11-04 16:00 | 1288.88 |
| 2026-11-02 00:00 | 1288.55 | 2026-11-04 22:00 | 1288.75 |
| 2026-11-01 00:00 | 1288.4 | 2026-11-05 04:00 | 1288.61 |
| 2026-10-30 23:00 | 1288.55 | 2026-11-05 10:00 | 1288.47 |
| 2026-10-29 23:00 | 1288.65 | 2026-11-05 16:00 | 1288.33 |
| 2026-10-28 23:00 | 1288.69 | 2026-11-05 22:00 | 1288.19 |
| 2026-10-27 23:00 | 1288.64 | 2026-11-06 04:00 | 1288.04 |
| 2026-10-26 23:00 | 1288.29 | 2026-11-06 10:00 | 1287.9 |
| 2026-10-25 23:00 | 1288.03 | 2026-11-06 16:00 | 1287.75 |
| 2026-10-24 23:00 | 1287.76 | 2026-11-06 22:00 | 1287.6 |
| 2026-11-07 04:00 | 1287.45 | ||
| 2026-11-07 10:00 | 1287.3 | ||
| 2026-11-07 16:00 | 1287.16 | ||
| 2026-11-07 22:00 | 1287.01 | ||
| 2026-11-08 04:00 | 1286.86 | ||
| 2026-11-08 10:00 | 1286.72 | ||
| 2026-11-08 16:00 | 1286.58 | ||
| 2026-11-08 22:00 | 1286.44 | ||
| 2026-11-09 04:00 | 1286.31 | ||
| 2026-11-09 10:00 | 1286.17 | ||
| 2026-11-09 16:00 | 1286.04 | ||
| 2026-11-09 22:00 | 1285.91 | ||
| 2026-11-10 04:00 | 1285.79 | ||
| 2026-11-10 10:00 | 1285.66 | ||
| 2026-11-10 16:00 | 1285.54 | ||
| 2026-11-10 22:00 | 1285.42 | ||
| 2026-11-11 04:00 | 1285.31 | ||
| 2026-11-11 10:00 | 1285.19 | ||
| 2026-11-11 16:00 | 1285.08 | ||
| 2026-11-11 22:00 | 1284.96 | ||
| 2026-11-12 04:00 | 1284.85 | ||
| 2026-11-12 10:00 | 1284.73 | ||
| 2026-11-12 16:00 | 1284.61 | ||
| 2026-11-12 22:00 | 1284.5 | ||
| 2026-11-13 04:00 | 1284.39 | ||
| 2026-11-13 10:00 | 1284.27 | ||
| 2026-11-13 16:00 | 1284.16 | ||
| 2026-11-13 22:00 | 1284.05 | ||
| 2026-11-14 04:00 | 1283.94 | ||