Fly Fish ForecastBeta

Hatch predictions for 300+ US rivers — built from live water & weather, then confirmed against real fly-shop reports.

← All rivers

Tomorrow River Near Nelsonville

Tomorrow River · Driftless / Midwest · USGS gage 04080798

Coldwater (summer mean 15.4°C — prime coldwater).

Water
51°F
Flow
33 cfs
Air
69°F
Sky
0%
Predicted hatches · 2026-06-16
PredictedGreen DrakeDrunella spp.0.80
Predicted by conditions; no reports yet. water 10.8°C (51°F) is warming toward the prime band (11-15°C); peak season; watch midday, often cloudy.
flies: Green Drake Parachute #10-12, Cripple, Hares Ear #10
PredictedMidgeChironomidae0.43
Predicted by conditions; no reports yet. water 10.8°C (51°F) is cooling past the prime band (1-10°C); shoulder of the season; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge

PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.