Peakflow Forecasts Header

GREEN--HOWARD HANSON DAM
   State:  Washington    County:  KING
   Latitude:  47 16' 40" North    Longitude:  121 47' 13" West
   Elevation:  1206 feet
   Supporting WFO:  Seattle    
   Inflow Data  

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.

GREEN--HOWARD HANSON DAM   (HHDW1)
Forecasts for Water Year
2025
Ensemble Date: 2025-05-15
Forecast Period: May 15 to September 1
Exceedence
Probability
Inflow
CFS
Probable
Date of Peak
95 % 849 2025-05-18
90 % 849 2025-05-18
70 % 849 2025-05-18
50 % 1142 2025-05-31
30 % 1534 2025-06-08
10 % 2435 2025-06-19
05 % 2749 2025-07-06

Peakflow exceedence plot for HHDW1

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