Peakflow Forecasts Header

WILLAPA--NEAR WILLAPA
   State:  Washington    County:  PACIFIC
   Latitude:  46 39' 3" North    Longitude:  123 39' 7" West
   Elevation:  4 feet
   Supporting WFO:  Portland    
   Action Stage:  20'   Flood Stage:  21'   Moderate Flood Stage:  22'
   Major Flood Stage:  24'

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.

WILLAPA--NEAR WILLAPA   (WILW1)
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 % 3.64 136 2026-06-14
90 % 3.64 136 2026-06-14
70 % 3.64 136 2026-06-14
50 % 3.81 167 2026-08-21
30 % 4.15 239 2026-09-19
10 % 4.88 420 2026-09-30
05 % 5.90 744 2026-10-01

Peakflow exceedence plot for WILW1

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