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SALT LAKE CITY — Glen Merrill wasn't alone in fearing the worst as Utah's snowpack surged to 30 inches for the first time on record in early April.
This statewide average doesn't take into account many of the "mind-blowing" extremes happening in parts all over the state. Several high-elevation mountain locations in Utah surpassed 70 inches of snow water equivalent, including some that got over 80 inches. Mid-elevation locations were even "more anomalous" in his estimation, with some hitting 50 inches at 6,000 feet elevation.
It kept climbing, and what ended up in the mountains had to melt and come into the valleys at some point.
However, a mix of good planning, along with a series of fortunate weather events from late-April into June, ultimately spared Utah from the type of widespread flooding that Merrill, a meteorologist and hydrologist for the National Weather Service, and others worried about.
"I'm going to argue that the snowmelt runoff this year was as efficient as it could have been," he said during a Utah Emergency Management Administration council meeting Tuesday morning. "The chances of that occurring are very, very small. The chances of having a record-breaking snowpack is very, very small, so they kind of played off each other."
While the snowmelt flooding threat is gone — as about 99.3% of that 30-inch snowpack has melted — Merrill and other experts warned the council that Utah isn't necessarily out of the woods when it comes to impacts tied to the snowpack. Wildfire risks are forecast to rise and drought conditions will likely worsen as warmer, drier conditions finally impact the state.
How Utah ended up with a near-perfect snowmelt
Flood preparation work began while snow was still falling in the mountains. Several water managers began releasing water from reservoirs early when they realized there was more water in the mountains than reservoirs had capacity to hold. State, county and municipal crews also got to work clearing out as much brush and debris as possible in snowmelt-fueled creeks and streams, to avoid buildup-caused flooding as possible.
Even then, experts routinely said the weather would ultimately determine flood impact. Those worries Merrill and others expressed were ultimately quelled when the weather cooperated.
Utah's snowmelt eventually began the second week of April. This initial melt was a little more even because Utah's average temperature in April ended up at 44.4 degrees, 1.1 degrees below the 20th century average.
On top of that, some additional mid-April storms helped pause the snowmelt in the northern half of the state until the end of the month. Then, in May, when the average temperature jumped up to 57.8 degrees, which is 3.1 degrees above normal, weeks of peculiar storm activity lessened the blow by slowing the melting process down to rates "that were within a window of very efficient runoff," Merrill explained.
You can thank the weather gods for how it panned out. ... It's exactly what we needed for how much snow we had left.
–Glen Merrill, National Weather Service
This continued into June, resulting in high-elevation locations melting more evenly than expected. Merrill said the snowmelt fueling Little Cottonwood Creek exemplified most other waterways. It never reached flood stage because the melt was spread out over a longer period of time than in a bad flood year like 1983.
"You can thank the weather gods for how it panned out. ... It's exactly what we needed for how much snow we had left," he said. "We saw localized flooding — we weren't going to escape that — but we didn't see that widespread historical flooding that we could have experienced if the weather had not behaved the way that it did."
The Natural Resources Conservation Service notes there are 0.2 inches of statewide snowpack still left, but all that remains is not enough to cause a risk of flooding. The efficient runoff helped many of the state's reservoirs reach capacity this month, and the state's reservoir system, combined, is up to 86% full, as compared to 42% in November.
Utah's drought situation also drastically improved since the start of the 2023 water year in October. A little more than 10% of Utah remains in moderate drought, while the rest of the state is either abnormally dry, or out of any drought status, according to the U.S. Drought Monitor.
Wildfire risk increasing, landslide risk decreasing
Despite the series of storms in April and May, both months actually ended up producing below-normal precipitation statewide, according to the National Centers for Environmental Information, which compiles weather service data. Combined, the two months ended up 0.89 inches below the 20th century normal.
That odd daily storm activity is coming to an end, helping temperatures finally reach closer to normal for the start of summer. Merrill says drier conditions are likely to persist for at least the next few weeks, and it's highly possible that this summer's monsoon season won't be as strong, as an El Niño oceanic pattern emerges after three winters of La Niña.
"When you put (the oceanic pattern sequence) together, the development of the North American monsoon is both delayed further into the summer and it's typically weaker than normal," Merrill said. "So we're going to be seeing drying conditions moving forward and we're going to start seeing wildfire potential in our grasses, especially, start ramping up here pretty quickly."
The Great Basin Coordination Center lists a higher fire risk in southeastern Utah this week, but it still lists Utah as having a "normal" fire risk throughout the summer, overall.
Merrill adds that Utah's drought improvement will likely come to an end, as well, with the precipitation slowdown.
However, the state's landslide risk is slowly improving as soil moistures continue to dry. Bill Keach, director of the Utah Geological Survey, told the council he expects Utah will be prone to slides for about another month — unless there is a wetter-than-normal summer.
That update comes after the division reported more than 200 landslides over the past few months, well above the normal of about 100. Keach suspects there have been hundreds more, likely in remote parts of the state where they weren't reported. He said state geologists will visit those areas this summer to see if that's the case.
Some of this is because of highly-saturated soils, but he contends construction is another large factor for all the slides.
"They're all over the place, in different types of soils," he said. "They're exposing areas that we maybe should not have built on, or we didn't mitigate properly. We mitigated and it worked great in dry years. It didn't work in wet years."
Long-term forecast?
It's difficult to forecast beyond summer, but all signs are pointing to an El Niño winter. But much like a La Niña winter, which Utah is coming off a third-straight time, the results vary from year to year.
While El Niño traditionally brings more moisture through the Southwest and warmer air through the Pacific Northwest, the Beehive State is traditionally caught in between — with parts of northern Utah a little more likely to have warmer temperatures.
The only certainty with either pattern happens when there's a storm cycle, like what happened this past winter. Yet those are different to project well in advance. So, what can Utahns expect moving beyond this summer?
"Roll the dice," Merrill says.
That means we'll have to wait and see.
