“Forecasts for spring and summer runoff in Montana are the lowest in the Red Rock, Ruby, and Madison River basins."
The above graph really puts it into perspective. It's gonna be a bumpy ride for drift boats this year. All those brand new boats people are itching to use this summer. Not gonna look so new after this season. While it's not the easiest graph to interpret, essentially what it is saying here is, there's a 30% chance that we hit 100% of average for streamflows (KAF or % of average are the unit options. I chose % of average. KAF stands for thousands of acre feet) this season on the upper Madison. Don't like those odds. Further, there's a 50% chance that we hit 90% of average, a 70% chance we hit 80% of average, and a 95% chance that we hit a mere 68% of average.
No doubt it's been a roller coaster snow year. Starting off dry with below average snow, moving to a record setting February that got everyone's hopes up for a recovery in snowpack, and now back to an underwhelming and slightly concerning March snowfall. If it weren't for February snowfall records, we'd be in a really bad spot right now.
While some basins aren't that far off from normal, the upper Madison Basin found itself on the especially naughty list according to Lucas Zukiewicz, USDA Natural Resources Conservation Service (NRCS) water supply specialist for Montana. With only 10 days until we hit the median peak date for snow in the upper Madison, it's safe to say we're not gonna catch normal this year. Thankfully, the high country snowpack is better insulated from above normal temperatures and hasn’t transitioned to discharge just yet according to Luke. Any way you shake it, this year's runoff will be mild. Here's a graphical representation of current snow water equivalent.
Precipitation was down in March:
Average air temp was above normal:
Right now the upper Madison Basin is sitting at 86% of Average.
This next graph is a forecast of streamflows to visualize the relationship between snowpack and the response of regional rivers and streams during spring and summer runoff. It takes a second of staring at this to see what's going on. It's just the same information we've been talking about in a different representation. Low snow year is going to equal shorter and less intense runoff.
Grease up those drift boats. It could get bumpy.