River Rat
Live conditions and a seasonal streamflow outlook for Montana & Idaho float runs, built from public USGS, NRCS, and NOAA data.
What you're looking at
Each river card shows a few things you can act on:
- A status stamp — is the river runnable right now? Color-coded against a section-specific cfs window (red = unrunnable, amber = bony or pushy, green = ideal).
- A plain-language summary — current status and, where we forecast it, the next time that status is expected to change.
- A chart — the last 45 days of observed flow, a near-term forecast, and, on rivers where our model earns it, a long-range outlook with a likely range. Color-block bands mark the section's runnable window.
Not for safety-critical decisions. These are rough planning forecasts. Check the live USGS gauge and current NWS conditions before launching. A river inside the runnable zone at the gauge can still be very different at any specific rapid.
How the Forecast Works
We show two kinds of forecast, and they answer different questions.
- Near-term — the next week or so. NOAA's short-range river forecast for the days right ahead of you, refreshed daily. The call for "is this weekend going to work?"
- Long-range — the rest of the season. Our own weekly outlook that looks several weeks ahead, with a likely range around it. The call for "when should I plan my trip?"
We publish the long-range outlook only on rivers where it has proven, in back-testing, to beat a simple seasonal average — and only as far ahead as it stays reliable. On regulated or rain-driven rivers, and anywhere the model can't earn its keep, cards show live conditions and a near-term forecast where one's available. We'd rather show less than overpromise.
How Often It Updates
- Hourly — live conditions (current flow, plus gauge height, water temperature, and nearby air quality where available) refresh every hour.
- Daily — the near-term forecast refreshes every day.
- Weekly — every Monday morning Mountain Time, the long-range outlook is regenerated for each river.
- Monthly — on the first of each month, the model behind the long-range outlook is rebuilt from scratch.
Limits and Caveats
- Long-range outlook is for snowmelt rivers. It's built for rivers whose flow is driven by melting snowpack. Regulated and rain-driven rivers show live conditions and, where available, a near-term forecast.
- Weekly resolution. The long-range outlook is week-by-week, not day-by-day. Variation within a week isn't modeled.
- A gauge is one point on the river. Flow at your put-in can differ from the gauge reading, especially below tributaries. Always check the section you're actually running.
- Track record still building. Production forecasts started in April 2026. A meaningful forecast-vs-observed skill assessment will be possible after the 2026 snowmelt season.