Chehalis River Near Grand Mound flow report
As of July 13, 2026, Chehalis River Near Grand Mound is flowing at 313 cfs with a gage height of 129.12 ft, holding steady over the past 24 hours. Source: USGS gauge #12027500, refreshed throughout the day.
Historical Data
Chehalis River Near Grand Mound at a glance
How Chehalis River Near Grand Mound is running right now, where it sits on the map, and the key gauge stats.
Chehalis River Near Grand Mound is flowing at 313 cfs, with the water sitting 129.12 ft at the gage. Flow has held roughly steady over the past 24 hours.
This is USGS gauge #12027500 in Washington. Over the past 10 days the average has been 343 cfs, peaking at 397 cfs.
Over the next 5 days, Chehalis River Near Grand Mound is expected to recede from today's 317 cfs, toward roughly 274 cfs by 2026-07-17 (likely range 140-535 cfs) -- drier than normal for the date.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Washington flow report.
Streamflow Forecast
Powered by PULSE — Snoflo’s Predictive Unified Learning & Simulation Engine, which learns from how this river has answered every past storm, snowmelt, and dry spell to forecast where it’s headed with a precision generic models can’t match.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Chehalis River Near Grand Mound
The river is fed by several smaller tributaries and is affected by two major dams, Mayfield and Chehalis. Seasonally, the river exhibits a predictable pattern of higher flows in the fall and winter months due to increased precipitation. Interestingly, the Chehalis River is known for its significant annual flooding, with the most severe recorded in 2007. This underscores the importance of monitoring and managing this river system for the safety of local communities and ecosystems.
Nearby streamflow levels
Cross-check Chehalis River Near Grand Mound's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Chehalis River Near Grand Mound | 313 cfs |
| Skookumchuck River Near Bucoda | 126 cfs |
| Chehalis River Near Adna | 98 cfs |
| Newaukum River Near Chehalis | 64 cfs |
| Skookumchuck River Bl Bldy Run Cr Nr Centralia | 102 cfs |
| Nf Newaukum River Above Bear Creek Near Forest | 73 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Chehalis River Near Grand Mound. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Kelso-Longview Airport | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Chehalis River Near Grand Mound.
Boat launches
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River runs
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River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Chehalis River Near Grand Mound in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Chehalis River Near Grand Mound crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Chehalis River Near Grand Mound
Where does the streamflow data for Chehalis River Near Grand Mound come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 12027500. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Chehalis River Near Grand Mound rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Chehalis River Near Grand Mound report
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