Jay Burrows is heading for the Collins Lift in the Alta Ski Area when fresh snow falls on December 9th. A series of storms since December 9th will bring Utah’s snowpack back above average by 2022. (Spenser Heaps, Deseret News)
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SALT LAKE CITY – Utah’s Water Year 2022 is only 3 months old and it’s been a crazy ride.
It opened with a very strong start to finish near record lows in early December. Thanks to several large snowstorms at the end of 2021, which increased the snowpack in Utah sevenfold, the state will start the calendar year 2022 with above-average snowpack.
How long this will take, however, depends on the fact that the next few months remain stormy.
“We’re sitting well at the moment, but we need to continue in a similar fashion (more storms),” said Glen Merrill, a hydrologist with the National Weather Service’s Salt Lake City office.
And unfortunately, some long-term projections point to a possible slowdown in the not-too-distant future, especially for some parts of the state. It leaves questionable how big the snowpack will be once it flows into Utah’s reservoirs that have suffered from years of drought.
Utah’s Snowpack 2022 roller coaster
Saturday may be the start of the New Year, but it’s roughly halfway through Utah’s 2022 snow collecting season – based on the averages, at least. The normal peak is usually around April 4, when the snow begins to melt in the Utah mountains and pour into the state’s streams, rivers, lakes, and reservoirs.
The snow cover is a measure of how much water there is in the snow. This is important because snow cover and spring runoff make up over 90% of Utah’s water supply. A good year of snow is vital for Utah to weather the current drought, which began back in 2020. Every winter storm is crucial for the state’s water supply.
Last year around this time, a mixture of dry fall and below-average snow cover contributed to the country’s collective storage system dropping to 50%, and sometimes even below half.
This time it is different thanks to a rapid trend reversal in the last few weeks of the year after a strong start to the water year 2022.
“It was a roller coaster ride,” said Merrill, describing the last few months of snow gathering.
The water year began on October 1, and Utah’s collective snowpack hit 262% of normal by the end of the first month, according to data from the Natural Resources Conservation Service.
But that didn’t take long. A series of high pressure systems built over the west resulted in one of the warmest, driest November in Utah ever. This meant that not only could Utah fail to replenish its early snowpack, but some of it had already melted.
“We lost pretty much all of October’s snowpack, for all aspects, below 9,500 feet, except for the high, north-facing terrain,” said Merrill. “By December 9th, we had absolute minimum snowpack for that date across the state.”
Incidentally, this is also the reason why ski areas have suddenly postponed the opening days.
The data shows that snowpack reached almost a record high in mid-October and then fell to a record low in the first week of December. The nationwide snowpack sank to 31% of normal by December 6th.
Then something happened, almost as if someone were twisting a hose at full speed.
The high pressure patterns that dominated the region in November and early December intensified, but moved west toward the eastern Pacific Ocean and then north toward Alaska, Merrill said. This opened the door to storm activity in the western US
“So on the east side, the downstream side of that high pressure, we developed a longwave valley – a wide depression where all of our storm activity essentially comes from the Arctic and then falls down the west coast and rotates through us,” he said. “It was one storm after another, because the strength and size of the high pressure contrasted with the strength and size of this mean low pressure system over Intermountain West. “
When that happens, he adds, it’s harder to break the patterns. The end result in this case was a series of storms that devastated the entire region in dire need of snow for the past three weeks.
For example, Lake Tahoe, on the California-Nevada border, broke a December record with over 193.7 inches (over 16 feet) of snow, according to the University of California’s Berkeley Central Sierra Snow Lab. The region will close the month with over 210 inches of snow.
This graph, created by the Natural Resources Conservation Service, shows Utah’s total snowpack for the year 2022 in relation to 30-year normal values and 40-year extreme values. The black line representing the current year fell below the record lows (red line) in early December, but is now above average (green line). (Photo: Nature Conservation Service)
Utah got a good deal of snow too. The Natural Resources Conservation Service’s snowpack collection knife changed drastically after December 9, when the first of several storms hit the state. According to data collected on Friday lunchtime, the state-wide snowpack of Utah currently contains about 7.1 inches of water, seven times more than it was on December 9 – with more snow forecast by Saturday morning.
Within a few weeks it rose from 31% of the normal value to well above the normal value for New Years.
According to data collected on Friday lunchtime, it’s now 126% – with more snow forecast by Saturday morning.
These maps show Utah’s snowpack for the water year 2022 based on the December 5, 2021 average and Friday. The snowstorms in recent weeks have shifted the snowpack across the country from 31% of the average to 126% of the average during this period. (Photo: Nature Conservation Service)
But as Merrill points out, there are still three months into the snowpack season and a lot more snow will be needed to stay on track for the snowmelt season. Utah’s national snowpack currently holds about 7.1 inches of water. It is usually around 15.8 inches when the snowpack usually starts to melt in early April.
“We have a long way to go,” he said. “We’re not even halfway there.”
How long will the storms last?
There is a shift in patterns in the East Pacific that will still create storms in the west in the near future, but the northern parts are more likely to maintain them.
Long-term forecast from the National Weather Service Climate Prediction Center suggests a more traditional La Nina pattern emerging after the series of storms in December. Its 10-day and one-month outlook paints a bright picture for northern Utah, with the odds of above-average rainfall tending towards the beginning of the 2022 calendar year. However, the graphs also show higher chances of a slowdown in southern Utah.
“That’s the pattern that seems to be more favorable for January, February and March and that will continue into the future,” Merrill said.
The centre’s three-month outlook shows that the chances of an above-average dry end of the snow-gathering season are higher in central and southern Utah, while northern Utah is considered “equal chances” or that it is still unclear whether winter will be and early spring becomes wetter or drier than average.
Published December 16 by the Climate Prediction Center, this map shows the precipitation probabilities for January, February, and March. Areas in southern and central Utah are more likely to experience above-average drought over three months, especially towards the end of winter and early spring, according to the weather service. (Photo: Center for Climate Prediction)
None of this means that there will be no storms anywhere in Utah by the end of the snow-gathering season. What it means is that the nationwide snowpack, which has seen a massive turnaround, is likely to begin to level off.
The biggest question for 2022 is how much.
Merrill said that average snowmelt melting compared to average snowmelt will still help alleviate Utah drought conditions and replenish the state’s reservoirs; it just wouldn’t be a “drought buster”. This is because the drought was so severe and temperatures well above average have evaporated some of the moisture that has fallen since 2019.
It would help fill up some of the smaller reservoirs again. From a hydrological point of view, several years of above-average snow cover seasons are likely to be required to replenish larger reservoirs like Lake Powell, which has fallen to a record low, and to “fully recharge the system”.
On the plus side, the humidity of the past few months makes for the likelihood of a more efficient runoff in the spring of 2022.
How much water will get into the reservoirs, hydrologists like Merrill are still in a wait and see mode. You keep your fingers crossed that many more storms are forecast at the end of winter.
“(The December storms were) beneficial in the short term, but we really want them to last longer,” Merrill said. “(You will be required) throughout April to maintain these current levels.”
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