Peakflow Forecasts Header

COLUMBIA--BLO PRIEST RAPIDS DAM
   State:  Washington    County:  GRANT
   Latitude:  46 37' 59" North    Longitude:  119 52' 0" West
   Elevation:  388 feet
   Supporting WFO:  Spokane    
   Action Stage:  31'   Flood Stage:  32'   Moderate Flood Stage:  33'
   Major Flood Stage:  
34'

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.

COLUMBIA--BLO PRIEST RAPIDS DAM   (PRDW1)
Forecasts for Water Year
2026
Ensemble Date: 2026-02-06
Forecast Period: February 6 to June 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 17.98 152820 2026-02-25
90 % 18.54 159948 2026-02-28
70 % 19.50 172577 2026-05-06
50 % 20.53 186861 2026-05-28
30 % 22.04 208634 2026-06-01
10 % 23.54 232520 2026-06-01
05 % 24.88 256101 2026-06-01

Peakflow exceedence plot for PRDW1

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