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 2025
Ensemble Date: 2025-07-15
 Forecast Period: July 15 to November 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 151.89 251 2025-08-18
90 % 152.35 378 2025-09-11
70 % 153.24 666 2025-10-14
50 % 155.61 1771 2025-10-24
30 % 157.64 3210 2025-10-31
10 % 160.46 6211 2025-11-01
05 % 163.07 10262 2025-11-01

Peakflow exceedence plot for CENW1

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