Peakflow Forecasts Header

SNAKE--LOWER GRANITE DAM
   State:  Washington    County:  WHITMAN
   Latitude:  46 42' 0" North    Longitude:  117 25' 59" West
   Elevation:  738 feet
   Supporting WFO:  Spokane    
   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.

SNAKE--LOWER GRANITE DAM   (LGDW1)
Forecasts for Water Year
2025
Ensemble Date: 2025-05-12
Forecast Period: May 12 to September 1
Exceedence
Probability
Inflow
CFS
Probable
Date of Peak
95 % 126180 2025-05-13
90 % 126180 2025-05-13
70 % 126180 2025-05-13
50 % 126180 2025-05-13
30 % 126180 2025-05-13
10 % 145870 2025-06-06
05 % 167796 2025-06-10

Peakflow exceedence plot for LGDW1

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