Peakflow Forecasts Header

CHEHALIS--NEAR GRAND MOUND
   State:  Washington    County:  THURSTON
   Latitude:  46 46' 33" North    Longitude:  123 2' 9" 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
2024
Ensemble Date: 2024-03-28
Forecast Period: March 28 to July 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 134.90 6094 2024-03-30
90 % 134.90 6094 2024-03-30
70 % 134.90 6094 2024-03-30
50 % 134.90 6094 2024-03-30
30 % 136.01 7949 2024-04-16
10 % 137.69 11119 2024-05-07
05 % 139.74 15769 2024-05-14

Peakflow exceedence plot for CGMW1

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