Peakflow Forecasts Header

JOHNSON CREEK--AT SYCAMORE
   State:  Oregon    County:  MULTNOMAH
   Latitude:  45 28' 40" North    Longitude:  122 30' 24" West
   Elevation:  228 feet
   Supporting WFO:  Portland    
   Action Stage:  10'   Flood Stage:  11'   Moderate Flood Stage:  13'
   Major Flood Stage:  
14'

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.

JOHNSON CREEK--AT SYCAMORE   (SYCO3)
Forecasts for Water Year
2025
Ensemble Date: 2025-07-02
Forecast Period: July 2 to November 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 1.69 17 2025-07-17
90 % 1.76 20 2025-08-14
70 % 2.04 33 2025-10-09
50 % 2.23 43 2025-10-22
30 % 3.23 113 2025-10-29
10 % 5.05 293 2025-11-01
05 % 7.88 686 2025-11-01

Peakflow exceedence plot for SYCO3

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