Peakflow Forecasts Header

CHEHALIS--NEAR CENTRALIA
   State:  Washington    County:  LEWIS
   Latitude:  46 42' 42" North    Longitude:  122 58' 43" West
   Elevation:  185 feet
   Supporting WFO:  Seattle    
   Action Stage:  166'   Flood Stage:  168.5'   Moderate Flood Stage:  172'
   Major Flood Stage:  175.5'

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.

CHEHALIS--NEAR CENTRALIA   (CENW1)
Forecasts for Water Year 2026
Ensemble Date: 2026-06-14
 Forecast Period: June 14 to October 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 152.89 547 2026-06-14
90 % 152.89 547 2026-06-14
70 % 152.89 547 2026-06-14
50 % 153.17 641 2026-07-15
30 % 153.58 795 2026-09-10
10 % 154.36 1121 2026-09-28
05 % 156.49 2334 2026-09-30

Peakflow exceedence plot for CENW1

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