Peakflow Forecasts Header

COWLITZ--AT RANDLE
   State:  Washington    County:  LEWIS
   Latitude:  46 31' 57" North    Longitude:  121 57' 20" West
   Elevation:  890 feet
   Supporting WFO:  Seattle    
   Action Stage:  13.2'   Flood Stage:  18'   Moderate Flood Stage:  20'
   Major Flood Stage:  22'

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.

COWLITZ--AT RANDLE   (RAWW1)
Forecasts for Water Year 2026
Ensemble Date: 2026-09-10
 Forecast Period: September 10 to January 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 8.24 4120 2026-11-01
90 % 8.68 4670 2026-11-05
70 % 11.75 8665 2026-11-23
50 % 15.02 13216 2026-11-30
30 % 18.36 18083 2026-12-09
10 % 23.16 32252 2026-12-20
05 % 25.41 42460 2026-12-27

Peakflow exceedence plot for RAWW1

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