Peakflow Forecasts Header

CHEHALIS--NEAR GRAND MOUND
   State:  Washington    County:  THURSTON
   Latitude:  46 46' 34" North    Longitude:  123 2' 4" West
   Elevation:  124 feet
   Supporting WFO:  Seattle    
   Action Stage:  138.5'   Flood Stage:  141'   Moderate Flood Stage:  142.5'
   Major Flood Stage:  
144'

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.

CHEHALIS--NEAR GRAND MOUND   (CGMW1)
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 % 138.18 12119 2021-12-13
90 % 138.18 12119 2021-12-13
70 % 140.50 18064 2021-12-31
50 % 142.03 22827 2022-01-12
30 % 142.64 27068 2022-01-25
10 % 144.96 48399 2022-02-20
05 % 145.88 59521 2022-03-03

Peakflow exceedence plot for CGMW1

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