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: 2026-03-14
Forecast Period: March 14 to July 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 13.09 4221 2026-03-14
90 % 13.09 4221 2026-03-14
70 % 13.09 4221 2026-03-14
50 % 13.09 4221 2026-03-14
30 % 13.09 4221 2026-03-14
10 % 16.06 6177 2026-03-29
05 % 16.58 6544 2026-04-12

Peakflow exceedence plot for WILW1

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