Peakflow Forecasts Header

SOUTH PRAIRIE--AT SOUTH PRAIRIE
   State:  Washington    County:  PIERCE
   Latitude:  47 7' 59" North    Longitude:  122 4' 59" West
   Elevation:  430 feet
   Supporting WFO:  Seattle    
   Action Stage:  28.58'   Flood Stage:  29.34'   Moderate Flood Stage:  30.28'
   Major Flood Stage:  
31.55'

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.

SOUTH PRAIRIE--AT SOUTH PRAIRIE   (SPEW1)
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 % 27.01 1275 2021-12-12
90 % 27.01 1275 2021-12-12
70 % 28.00 1951 2022-01-04
50 % 28.70 2533 2022-01-15
30 % 29.52 3495 2022-01-31
10 % 30.61 5140 2022-02-22
05 % 30.82 5493 2022-03-02

Peakflow exceedence plot for SPEW1

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