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: 2026-09-10
Forecast Period: September 10 to January 1
Exceedence
Probability
Inflow
CFS
Probable
Date of Peak
95 % 1046 2026-11-17
90 % 1560 2026-11-22
70 % 2254 2026-12-07
50 % 3786 2026-12-14
30 % 6959 2026-12-21
10 % 16756 2026-12-29
05 % 21682 2026-12-30

Peakflow exceedence plot for FRNO3

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