Peakflow Forecasts Header

GRANDE RONDE--NEAR PERRY
   State:  Oregon    County:  UNION
   Latitude:  45 21' 15" North    Longitude:  118 11' 29" West
   Elevation:  2950 feet    Gage Datum:  
   Supporting WFO:  Pendleton    
   Action Stage:  5.8'   Flood Stage:  6.6'   Moderate Flood Stage:  7.5'

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.

GRANDE RONDE--NEAR PERRY   (LGNO3)
Forecasts for Water Year 2025
Ensemble Date: 2025-07-07
 Forecast Period: July 7 to November 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 1.07 43 2025-08-08
90 % 1.12 50 2025-08-20
70 % 1.27 72 2025-09-26
50 % 1.33 84 2025-10-21
30 % 1.41 99 2025-10-25
10 % 1.87 231 2025-10-30
05 % 1.93 250 2025-10-31

Peakflow exceedence plot for LGNO3

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