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NF STILLAGUAMISH--NEAR ARLINGTON
   State:  Washington    County:  SNOHOMISH
   Latitude:  48 15' 38" North    Longitude:  122 2' 51" West
   Elevation:  89 feet
   Supporting WFO:  Seattle    
   Action Stage:  10.7'   Flood Stage:  13'   Moderate Flood Stage:  14'
   Major Flood Stage:  15'

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.

NF STILLAGUAMISH--NEAR ARLINGTON   (ARGW1)
Forecasts for Water Year 2026
Ensemble Date: 2025-11-16
 Forecast Period: November 16 to March 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 7.67 9445 2025-11-30
90 % 8.36 10890 2025-12-04
70 % 9.78 14146 2025-12-16
50 % 10.57 16090 2026-01-03
30 % 11.54 18615 2026-01-18
10 % 13.99 25614 2026-02-16
05 % 14.51 27202 2026-02-22

Peakflow exceedence plot for ARGW1

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