One trick I have started to do is record the various river graph images as part of my photo collection for a given trip, and that way I can relate it to future trips. Especially helpful for trips with known high-water crossing difficulties, like Lincoln Brook (Owl's Head) or Gale River (Galehead), for example.
For example, on 11/17/07, the Pemi East Branch in Lincoln started the morning near 700 cfps and ended the day close to 500 cfps. Crossing Lincoln Brook, which drains to the East Branch, was doable with caution. The gauge height was 6.5 feet +/- .25 feet for that same 24-hour period.
I suspect that with snow and ice, the flows will be restricted some way and the three-season value(s) may not apply in winter. Ambitious Conditions reporters might consider including those value(s) as part of any description of river crossings.
Tim