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: 2025-07-08
 Forecast Period: July 8 to November 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 10.14 116 2025-09-05
90 % 10.50 202 2025-10-06
70 % 11.48 549 2025-10-20
50 % 11.88 730 2025-10-24
30 % 12.87 1304 2025-10-28
10 % 13.82 2078 2025-11-01
05 % 15.04 3314 2025-11-01

Peakflow exceedence plot for PILW1

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