Peakflow Forecasts Header

LONG TOM--FERN RIDGE DAM
   State:  Oregon    County:  LANE
   Latitude:  44 7' 24" North    Longitude:  123 17' 54" West
   Elevation:  374 feet
   Supporting WFO:  Portland    
   Inflow Data  

Forecasts are calculated from a forecast time series that approximates flow at a 6 hour time step interval. Observed instantaneous peaks can be higher than model forecast peaks.

LONG TOM--FERN RIDGE DAM   (FRNO3)
Forecasts for Water Year
2026
Ensemble Date: 2025-11-14
Forecast Period: November 14 to March 1
Exceedence
Probability
Inflow
CFS
Probable
Date of Peak
95 % 1249 2025-12-13
90 % 1498 2025-12-22
70 % 3269 2026-01-03
50 % 4090 2026-01-19
30 % 8056 2026-02-02
10 % 17018 2026-02-22
05 % 20320 2026-02-25

Peakflow exceedence plot for FRNO3

 Click to download runoff traces used in forecast.  Click for comma delimited data used in plot.csv icon