Peakflow Forecasts Header

SF STILLAGUAMISH--NEAR GRANITE FALLS
   State:  Washington    County:  SNOHOMISH
   Latitude:  48 6' 13" North    Longitude:  121 56' 44" West
   Elevation:  310 feet
   Supporting WFO:  Seattle    
   Action Stage:  12.9'   Flood Stage:  14'   Moderate Flood Stage:  16'
   Major Flood Stage:  
18'

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.

SF STILLAGUAMISH--NEAR GRANITE FALLS   (GFLW1)
Forecasts for Water Year
2022
Ensemble Date: 2021-12-07
Forecast Period: December 7 to April 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 9.40 7085 2021-12-12
90 % 9.40 7085 2021-12-12
70 % 9.64 7563 2021-12-24
50 % 10.88 10282 2022-01-15
30 % 11.88 12853 2022-02-11
10 % 13.21 16634 2022-03-12
05 % 13.96 18787 2022-03-23

Peakflow exceedence plot for GFLW1

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