When the clock strikes midnight on the final night of September, we all should "Happy New Water Year!". The water year in Montana ends on September 30th and the new water year beings on October 1st. This cycle is defined by these dates for tracking precipitation, snowpack, streamflow, reservoir levels, and overall water supply conditions. The water cycle is highly seasonal in this time frame, directly impacting wildlife, agriculture, recreation, hydropower, public water systems, even down to our drinking water.
Looking at the water year for the water basins in Montana and things are very good. Just about all of Montana's mountains have seen average or above average precipitation. The Tongue and Powder River Basins are slightly below average. The Rocky Mountain Front and the Sun-Teton-Marias Basin are a whopping 132% of normal.
While most of the mountains have had above average precipitation from last fall until now, precipitation in the lower elevations has been a little more variable. Helena's precipitation is more than 2.5" above normal, which is about 20% more than usual. Great Falls is also running about 20% above average for the water year. Lewistown and central Montana are just about at the historical average. Cut Bank and Havre are both running about an inche below normal, but farther out the Hi-Line, Glasgow has had almost 18" of precipitation compared to the usual of just over 13", that's more than 25% above normal.
With most of Montana having a good water year, parts of the state have been removed from drought status. So you certainly could say "Happy New Water Year!".
I'm meteorologist Curtis Grevenitz and now you are a little more Weather Wise.
