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:  28.88'   Flood Stage:  29.64'   Moderate Flood Stage:  30.5'
   Major Flood Stage:  
31.63'

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
2024
Ensemble Date: 2024-04-24
Forecast Period: April 24 to August 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 25.23 362 2024-05-03
90 % 25.26 376 2024-05-06
70 % 25.61 548 2024-05-13
50 % 25.65 572 2024-05-22
30 % 25.92 739 2024-06-02
10 % 26.47 1062 2024-06-15
05 % 27.10 1510 2024-06-27

Peakflow exceedence plot for SPEW1

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