Peakflow Forecasts Header

BIG LOST--AT HOWELL RANCH NEAR CHILLY
   State:  Idaho    County:  CUSTER
   Latitude:  43 59' 54" North    Longitude:  114 1' 16" West
   Elevation:  6622 feet
   Supporting WFO:  Pocatello    
   Action Stage:  3.51'   Flood Stage:  4'

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.

BIG LOST--AT HOWELL RANCH NEAR CHILLY   (HWRI1)
Forecasts for Water Year
2026
Ensemble Date: 2026-05-07
Forecast Period: May 7 to September 1
Exceedence
Probability
Stage
feet
Discharge
CFS
Probable
Date of Peak
95 % 2.66 903 2026-05-14
90 % 2.66 903 2026-05-14
70 % 2.70 936 2026-05-22
50 % 2.95 1124 2026-05-29
30 % 3.18 1328 2026-06-06
10 % 3.57 1706 2026-06-14
05 % 3.78 1933 2026-06-18

Peakflow exceedence plot for HWRI1

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