COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-03-27 08:40 PDT | ||
| Date/Time (PDT) | Inflow | Date/Time (PDT) | Inflow |
| 2026-03-27 00:00 | 145800 | 2026-03-27 17:00 | 138784.29 |
| 2026-03-26 00:00 | 119300 | 2026-03-27 23:00 | 139181.35 |
| 2026-03-25 00:00 | 124300 | 2026-03-28 05:00 | 139368.07 |
| 2026-03-24 00:00 | 131800 | 2026-03-28 11:00 | 139335.66 |
| 2026-03-23 00:00 | 126900 | 2026-03-28 17:00 | 139206.86 |
| 2026-03-22 00:00 | 113900 | 2026-03-28 23:00 | 139062.56 |
| 2026-03-21 00:00 | 113100 | 2026-03-29 05:00 | 138917.05 |
| 2026-03-20 00:00 | 97700 | 2026-03-29 11:00 | 138394.21 |
| 2026-03-19 00:00 | 103400 | 2026-03-29 17:00 | 136240.78 |
| 2026-03-18 00:00 | 103400 | 2026-03-29 23:00 | 131751.69 |
| 2026-03-17 00:00 | 102300 | 2026-03-30 05:00 | 126210.31 |
| 2026-03-30 11:00 | 121796.62 | ||
| 2026-03-30 17:00 | 119550.06 | ||
| 2026-03-30 23:00 | 118880.35 | ||
| 2026-03-31 05:00 | 118848.43 | ||
| 2026-03-31 11:00 | 118876.14 | ||
| 2026-03-31 17:00 | 118889.59 | ||
| 2026-03-31 23:00 | 118890.73 | ||
| 2026-04-01 05:00 | 118791.58 | ||
| 2026-04-01 11:00 | 118436.26 | ||
| 2026-04-01 17:00 | 117840.46 | ||
| 2026-04-01 23:00 | 117330.64 | ||
| 2026-04-02 05:00 | 117112.4 | ||
| 2026-04-02 11:00 | 117258.08 | ||
| 2026-04-02 17:00 | 117666.63 | ||
| 2026-04-02 23:00 | 118116.99 | ||
| 2026-04-03 05:00 | 118473.86 | ||
| 2026-04-03 11:00 | 118675.06 | ||
| 2026-04-03 17:00 | 118754.28 | ||
| 2026-04-03 23:00 | 118756.3 | ||
| 2026-04-04 05:00 | 118689.8 | ||
| 2026-04-04 11:00 | 118591.24 | ||
| 2026-04-04 17:00 | 118492.19 | ||
| 2026-04-04 23:00 | 118400.41 | ||
| 2026-04-05 05:00 | 118301.02 | ||
| 2026-04-05 11:00 | 118196.59 | ||
| 2026-04-05 17:00 | 118105.32 | ||
| 2026-04-05 23:00 | 118012.64 | ||
| 2026-04-06 05:00 | 117891 | ||