Peakflow Forecasts Header

BLACKFOOT--NEAR BONNER
   State:  Montana    County:  MISSOULA
   Latitude:  46 53' 58" North    Longitude:  113 45' 20" West
   Elevation:  3345 feet
   Supporting WFO:  Missoula    
   Action Stage:  9.5'   Flood Stage:  10'   Moderate Flood Stage:  16'
   Major Flood Stage:  17'

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.

BLACKFOOT--NEAR BONNER   (BONM8)
Forecasts for Water Year 2026
Ensemble Date: 2026-03-14
 Forecast Period: March 14 to July 1
Exceedence
Probability 		Stage
feet 		Discharge
CFS 		Probable
Date of Peak
95 % 5.47 4593 2026-04-24
90 % 5.63 4879 2026-04-30
70 % 6.04 5623 2026-05-18
50 % 6.38 6290 2026-05-26
30 % 6.69 6942 2026-05-31
10 % 7.48 8688 2026-06-10
05 % 8.09 10148 2026-06-21

Peakflow exceedence plot for BONM8

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