Thunder Bay River At Herron Road Near Bolton Flow Report
As of August 6, 2026, Thunder Bay River At Herron Road Near Bolton is flowing at 658 cfs with a gage height of 12.65 ft, rising 55% over the past 24 hours. Source: USGS gauge #04133501, refreshed throughout the day.
Historical Data
Thunder Bay River At Herron Road Near Bolton at a glance
How Thunder Bay River At Herron Road Near Bolton is running right now, where it sits on the map, and the key gauge stats.
Thunder Bay River At Herron Road Near Bolton is flowing at 658 cfs, with the water sitting 12.65 ft at the gage. Flow is up 55% since yesterday — a rising hydrograph.
This is USGS gauge #04133501 in Michigan. Over the past 10 days the average has been 598 cfs, peaking at 831 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Michigan flow report.
Engineering Data
Flow-duration statistics and observed peak-flow context computed from this gauge’s complete daily record (USGS #04133501).
Estimate flows at an ungauged site
Drainage-area ratio transfer from this gauge . Most reliable for hydrologically similar sites in the same watershed with area ratios between roughly 0.5 and 1.5.
Percentiles are flow-duration values computed from this gauge’s observed daily record as archived by Snoflo. Return periods are Weibull plotting-position estimates from observed annual maxima, provided as general reference context only. Always verify against official USGS NWIS records. Part of Snoflo for Engineering.
Streamflow Forecast
Over the next 5 days, Thunder Bay River At Herron Road Near Bolton is expected to recede from today's 424 cfs, toward roughly 371 cfs by 2026-08-10 (likely range 244-565 cfs) -- about normal for the date.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
| Date | Expected (p50) | Likely range (p25–p75) | vs normal | Projected stage |
|---|
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.
Thunder Bay River At Herron Road Near Bolton
The nearby Fletcher Pond and Alpena Dam may also impact the stream's flow. Seasonal trends show increased flow during the spring thaw and decreased flow during the summer months. Interestingly, the hydrology of this streamgauge is heavily influenced by the presence of beaver dams, which can cause significant variations in flow. Overall, this site provides valuable information on the hydrology of the Thunder Bay River and its surrounding areas.
Nearby streamflow levels
Cross-check Thunder Bay River At Herron Road Near Bolton's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Thunder Bay River At Herron Road Near Bolton | 658 cfs |
| Au Sable River Near Mc Kinley | 1,370 cfs |
| Au Sable River Near Curtisville | 1,320 cfs |
| Au Sable River At Mio | 1,460 cfs |
| Pigeon River At Sturgeon Valley Rd Near Vanderbilt | 133 cfs |
| Au Sable River Near Red Oak | 1,290 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Thunder Bay River At Herron Road Near Bolton. 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 |
|---|---|
| Phelps Collins Field | 5 in |
| Nohrsc Snow Paid Observer For Kapn | 0 in |
| Harrisville 2nne | 0 in |
| Vanderbilt 11ene | 0 in |
| Mio Wwtp | 0 in |
| Glennie 2se | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Thunder Bay River At Herron Road Near Bolton.
Boat launches
See all →
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 Thunder Bay River At Herron Road Near Bolton in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Thunder Bay River At Herron Road Near Bolton crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Thunder Bay River At Herron Road Near Bolton
What is the Thunder Bay River At Herron Road Near Bolton flow rate right now?
As of August 6, 2026, Thunder Bay River At Herron Road Near Bolton is flowing at 658 cfs. The live value, gage height, and 24-hour trend are shown at the top of this page.
Is the Thunder Bay River At Herron Road Near Bolton running high or low right now?
Check the percent of median figure on this page: above 100% means Thunder Bay River At Herron Road Near Bolton is running higher than normal for the date, below 100% means lower. The 24-hour trend shows whether it's rising or falling.
Where does the streamflow data for Thunder Bay River At Herron Road Near Bolton come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 04133501. 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 Thunder Bay River At Herron Road Near Bolton 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 Thunder Bay River At Herron Road Near Bolton report
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