Water agencies now ask whether a reservoir forecast is any good. They have not agreed on what to measure it against, so no two answers can be compared. A 52-year hindcast on a public reservoir shows what a properly benchmarked answer looks like, and how much a single headline skill number can hide.
The 2026 Pacific Northwest fire season has produced a water problem that has not started yet. The burn scars that matter for source water are not above Seattle or Portland. They are above Wenatchee, Lake Chelan, the Okanogan, the Yakima, The Dalles, Spokane's sole-source aquifer, and Boise.
NOAA is rebuilding the National Water Model on a new framework called NextGen. The next major release, NWM v4, will be the first to run on it. For projects that use NWM forecasts as a model input or a reference dataset, the character of those forecasts is about to change.
