Peakflow Forecasts Header

PILCHUCK--NEAR SNOHOMISH
   State:  Washington    County:  SNOHOMISH
   Latitude:  47 56' 6" North    Longitude:  122 4' 18" West
   Elevation:  0 feet
   Supporting WFO:  Seattle    
   Action Stage:  16'   Flood Stage:  18'   Moderate Flood Stage:  20'
   Major Flood Stage:  22'

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.

PILCHUCK--NEAR SNOHOMISH   (PILW1)
Forecasts for Water Year 2025
Ensemble Date: 2025-05-12
 Forecast Period: May 12 to September 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 10.32 171 2025-05-18
90 % 10.32 171 2025-05-18
70 % 10.78 315 2025-05-28
50 % 11.10 440 2025-06-09
30 % 11.75 770 2025-06-14
10 % 12.32 1142 2025-07-15
05 % 12.58 1338 2025-08-06

Peakflow exceedence plot for PILW1

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