With an extensive background in energy management and electricity delivery, Christopher Hailstone has a unique perspective on the state’s most critical resources. His expertise in grid reliability is intrinsically linked to the health of our water systems, from hydropower production to agricultural needs. As Montana grapples with a winter of extremes, we sat down with him to understand what the recent record-breaking precipitation really means for our water supply. This conversation unpacks the complex “tale of two snowpacks” that has emerged, exploring why seemingly positive data can be deceptive, the unusual conditions in the Lower Clark Fork basin, and how a warm forecast could drastically alter the outlook for the coming year.
December brought a deluge of precipitation, but it fell as snow at high elevations and rain at lower ones. How does this “tale of two snowpacks” complicate water supply forecasting, and what specific challenges does this create for managing resources throughout the year?
It creates a tremendous amount of uncertainty, which is the last thing you want in water management. That December atmospheric river was a perfect example; it was a massive event, with 70 of our 96 SNOTEL monitoring stations recording their highest or second-highest December precipitation on record. But where that moisture fell as snow versus rain makes all the difference. At high elevations, we built a fantastic, robust snowpack—a solid foundation for our water savings account. But thousands of feet below, that same storm came as rain, washing away the early snow we had and rushing straight into the rivers, causing flooding in some counties. This split reality means we can’t rely on statewide averages. We have to plan for two scenarios at once: managing a healthy, deep snowpack up high while simultaneously facing a potential deficit at lower elevations that could lead to critically low streamflows much earlier than usual.
Many major river basins are showing near-normal or even above-normal snow-water equivalent. Why might this be considered a “deceptively positive” situation, and what hidden risks could this mask for the state’s water supply as we head into spring and summer?
This is the critical point that I think many people miss. You look at a map and see basins like the Yellowstone at 120% of the median or the Gallatin at 107%, and it’s easy to breathe a sigh of relief. But that’s a dangerously simplistic view. Those impressive numbers are almost entirely driven by the massive snowfall at the highest elevations. The hidden risk is the poor condition of the snowpack at middle and lower elevations. This lower-elevation snow is what melts first in the spring, sustaining our river flows through April and May. If that part of the snowpack is weak or nonexistent because the precipitation came as rain, we could see an early, rapid runoff and then a sudden drop-off in water supply. That’s a nightmare scenario for ranchers needing to irrigate, for our aquatic ecosystems, and for maintaining water levels in reservoirs. The health of the peaks is masking the vulnerability of the valleys.
The Lower Clark Fork basin received over 200% of its normal December precipitation but still has a below-average snowpack. Can you explain the dynamics behind this outlier situation and what the practical implications might be for local water users and ecosystems?
The Lower Clark Fork is the poster child for this “tale of two snowpacks” we’re seeing. It was inundated with moisture, receiving a staggering 223% of its normal December precipitation. Yet, its snowpack is lagging at just 86% of the median. The dynamic is simple and stark: temperature. The storms that rolled through were unseasonably warm, so most of that moisture fell as rain, not snow. Instead of building that crucial frozen reservoir, the water caused immediate runoff and even flooding. For local water users, this is incredibly concerning. They experienced a deluge but have very little of it stored for the dry summer months. It’s a stark contrast to last year when the snowpack was at 112% at this time. This year, they face the real possibility of entering the summer with a significant water deficit, which will impact everything from agriculture to the local fishing and recreation economies.
With unseasonably warm temperatures in the forecast, what is the immediate risk to the existing snowpack, especially at those vulnerable lower elevations? Please walk us through how a warm spell now could change the water supply outlook for the rest of the season.
A warm spell in the middle of winter, with temperatures climbing into the upper 40s and 50s, is profoundly damaging to our water supply outlook. First, it halts any new snow accumulation at lower and mid-elevations. Second, and more critically, it actively melts the snowpack that’s already there. This isn’t a gentle, productive spring melt that slowly recharges groundwater. It’s a premature runoff event that sends water rushing down the system far too early. That water is effectively lost for the peak demand season in summer. It’s like spending your savings months before you need them. A few days of unseasonably warm weather now can erase any gains we’ve made and deepen the snow deficit at those vulnerable elevations, potentially shifting our entire water year from a mixed, hopeful start to a definitively concerning one.
What is your forecast for Montana’s water supply this year?
My forecast is one of cautious uncertainty, leaning toward concern if current weather patterns hold. We have a solid foundation thanks to the heavy snow at our highest elevations, which is a significant asset. However, that alone is not enough to guarantee a stable water supply through the summer. Our outlook is now entirely dependent on the weather over the next two to three months. We desperately need a return to colder temperatures and consistent snowfall, especially at those middle and lower elevations, to close the deficit that the warm December storms created. If we continue to see warm, rainy systems, we are on a path toward low spring and summer streamflows, which will have serious consequences. While there is still time for the situation to improve with a few good storm systems, the risk of facing another drought-impacted summer is very real.
