Peakflow Forecasts Header

CLACKAMAS--NEAR OREGON CITY
   State:  Oregon    County:  CLACKAMAS
   Latitude:  45 22' 45" North    Longitude:  122 34' 33" West
   Elevation:  15 feet
   Supporting WFO:  Portland    
   Action Stage:  38'   Flood Stage:  39'   Moderate Flood Stage:  42'
   Major Flood Stage:  46'

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.

CLACKAMAS--NEAR OREGON CITY   (COCO3)
Forecasts for Water Year 2027
Ensemble Date: 2026-10-10
 Forecast Period: October 10 to February 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 28.14 7456 2026-11-22
90 % 29.57 10618 2026-12-01
70 % 31.20 14601 2026-12-14
50 % 33.63 21269 2026-12-29
30 % 36.02 28967 2027-01-09
10 % 39.00 40068 2027-01-27
05 % 40.83 47666 2027-01-31

Peakflow exceedence plot for COCO3

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