Members of the National Weather Service in Great Falls met with Gallatin County Emergency Management and MTN meteorologists on Wednesday to discuss spring flooding.
The potential for major flooding in The Gallatin Valley over the next couple of months is low. This is partially due to the mountain snowpack being only slightly above normal despite a record-setting April in Bozeman for rainfall.
“We had an extremely wet April, which is great. It helps us build our mountain snowpack, so we have snow for this date which is about 115% of normal, at least for May 8 this time. Our forecast issued on May 1st that we should have near to above average flows in the Gallatin, east Gallatin and some of our smaller streams in this area.” NRCS Water Supply Specialist Lucas Zukiewicz.said.
Despite a few records being set this winter, it pales in comparison to wat we saw in 2018.
“We’re not quite where we were last year, but what we are at is closer to normal, which given how erratic this winter was with wet and dry months, it’s kind of surprising to come out right at normal. And normal flows or slightly above normal flows are great news for everyone in the area,” Zukiewicz.said.
Snowpack isn’t everything; how the snowpack melts and the rainfall we receive are both very important to the flood potential.
“Temperatures that remain above freezing overnight, so as long as we melt out during the day with warmer temperatures then freeze again at night, that creates a nice diurnal cycle of melting and kind of keeps flooding at a minimal level,” Senior Service Hydrologist Arin Peters said.
Take any long-range flooding outlooks with a grain of salt because when it comes to weather, things can change quickly.
“We do get heavy precipitation events. They’re not all that common in Montana, but they are a possibility. Last year we did have a pretty significant heavy precipitation event in north central Montana; that could easily happen down here this year, we don’t know.” Peters added.
A few days of well above average temperatures over the next few weeks can also lead to flooding here in the Valley.
