May storm improves outlook, but drought concerns persist for Montana

This week’s widespread, wet storm has brought a measure of relief to parts of Montana reeling from one of the driest winters on record, but water managers say it’s too early to tell how much of that water will stick around to sustain streams, crops and forests through the hottest months of the year.

“I think it’s fair to say that despite the pins and needles we’ve been on after that dry November and December, conditions this May are greatly improved from the last three [Mays],” said Michael Downey, the drought program coordinator with the state’s Department of Natural Resources and Conservation.

Downey said this week’s storm, which deposited several inches of moisture over much of the state, is a “game-changer.” 

“This is the multi-million dollar storm,” he said. “Some producers will have missed it, and others will be thanking their lucky stars that they got done planting.” 

Downey was speaking at a meeting on Thursday of the Governor’s Drought and Water Supply Advisory Committee where state and federal agencies outlined snowpack, precipitation, soil moisture and streamflow trends.

Forecasts still call for a hotter-than-normal summer, Downey said, and he anticipates an increase in the areas of drought in Montana unless more storms materialize.

“Temperature is a big factor for drought onset or removal,” he said. “When it comes to thinking about things like fire danger, we are still very much in wait-and-see mode.”

DNRC Director Amanda Kaster noted that a briefing on 2024 wildfire conditions is slated for early June when forecasters will have more information about the influence of May’s temperature and precipitation trends.

Although this week’s storm was widespread, there was significant regional variation in the amount of precipitation it brought. At the upper end, the Bear Paw Mountains of north-central Montana received 10.3 inches of moisture between May 1 and May 7, while lower elevations along the far northwestern corner of the state topped out at about 0.2 inches, according to a precipitation map produced by Zachary Hoylman with the Montana Climate Office. 

Hoylman said the precipitation appears not to have percolated very far into the soil across most of the state, so its ability to sustain plant growth through the hotter months ahead will be limited.

“Things have improved quite a bit, but we’re not seeing that deep percolation yet,” Hoylman said. “We’re starting with pretty dry soils, which impedes the flow of moisture deeper into the soil column. Time will tell.”

Eric Larson, a water supply specialist with the Natural Resources Conservation Service, noted that seven monitoring sites in western Montana reported their lowest-ever snowpacks on record for this water year, which started on Oct. 1, 2023. (The years of record at those monitoring stations range from 30 to 46 years.)

Sparse precipitation over the last several months, paired with cool temperatures that have slowed run-off, have resulted in some rivers in western Montana reporting record-low streamflow readings, according to Aaron Fiaschetti with the U.S. Geological Survey.

All of the meeting’s presenters agreed that it’s still too early to tell how far-reaching the recent storm’s impacts will be, especially since May and June are typically the wettest months of the year for most of the state and above-normal temperatures are predicted in the coming weeks.  

“I’ve been literally losing sleep over how dry it’s been,” Downey said. “I can rest a little bit easier now, though we’ll see how things fare in May and June.”