Peakflow Forecasts Header

CHEHALIS--AT PORTER
   State:  Washington    County:  GRAYS HARBOR
   Latitude:  46 56' 21" North    Longitude:  123 18' 50" West
   Elevation:  24 feet
   Supporting WFO:  Seattle    
   Action Stage:  45.5'   Flood Stage:  48'   Moderate Flood Stage:  50'
   Major Flood Stage:  52'

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--AT PORTER   (CRPW1)
Forecasts for Water Year 2025
Ensemble Date: 2025-07-03
 Forecast Period: July 3 to November 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 30.70 381 2025-07-08
90 % 30.99 496 2025-09-11
70 % 32.18 1076 2025-10-19
50 % 34.13 2378 2025-10-25
30 % 36.78 4770 2025-10-31
10 % 41.11 9450 2025-11-01
05 % 43.12 11774 2025-11-01

Peakflow exceedence plot for CRPW1

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