Milk River Basin - Water Supply Forecasts

Below-average to average natural runoff volumes are forecast for the March to September 2002 period in the Milk River basin (Table 2a). Current forecasts in the basin range from 49 to 95 % of the median. Current forecasted values for the March to September period for the Milk River at Milk River would rank 25th lowest in 84-years of record (1912-95). The June 1 forecasts changed significantly from last month's (increases between 10 and 40 %) due to a major snowstorm that impacted the headwaters portion of the basin in mid-May. Current runoff volume forecasts for this year are 28 to 71% higher than recorded runoff volumes last summer.

The first three months of the forecast period have been completed. The March-May 2002 recorded runoff volumes were below-average at Eastern Crossing and above-average at Western Crossing, ranging from 45 to 117 % of the median. The large difference in volume is attributed to the travel time of the river. The Milk River at Western Crossing peaked at the end of May and the peak had not reached Eastern Crossing as of May 31. Therefore, the difference in the percentage of the volume should be smaller next month. The remaining volume forecast, which is the March to September 2002 forecast minus the recorded volume to date, is available in Table 2b.