Winter’s start is still about 100 days away, and while the long-range forecasts are still in the icebox, climate experts are skeptical Utah will see another record-breaking cold season this year as the current trends suggest a limited opportunity to build an outstanding snowpack.
A three-month seasonal temperature and precipitation outlook released by the National Oceanic and Atmospheric Administration (NOAA) indicates a general warming pattern throughout most of the southern states with below-normal chances of precipitation in December, January and February.
The outlook gives a vague, general forecast of what the 2024-25 ski season could look like, but it’s hardly the most accurate. For a better sense, experts also look at current and past conditions to determine what might happen this winter.
Jonathan Meyer, the assistant state climatologist at the Utah Climate Center, tries to connect situation awareness with the outcomes experts expect to play out over sub-seasonal timescales, which is several weeks ahead to a month out, and then analyze the forecasts a few months to half a year forward.
The Utah Climate Center is charged with maintaining and archiving the state’s weather and climate records as well as providing a source of data and tools for all stakeholders ranging from individuals in the general public to larger state and federal agencies. Staff analyze conditions on the ground and how weather or climate events affect Utah’s landscape and impact conditions such as drought.
Meyer has been busy this summer monitoring the emergence of drought conditions throughout the state during the monsoon season, which was off to a pretty slow start this year. It was a very warm, dry transition from spring to summer and climate experts were worried about what would happen if those impacts returned after a quiet period.
Monsoonal rains returned over the last few weeks, providing cool relief and a decent amount of precipitation, particularly in northern Utah. Conditions have already started to dry out, but it was still a nice period of respite.
“Overall, the monsoon season hasn’t been tremendously underperforming, although I guess I wouldn’t necessarily call it a resounding success in terms of long-term drought relief, but it’s gotten us through in a way that has sort of held us neutral in terms of drought impacts,” Meyer said.
Experts are also looking at the possibility of a La Niña winter, which occurs when conditions are about a half degree or colder than normal. The National Weather Service Climate Prediction Center said there’s a 74% chance a La Niña will persist during the 2024-25 season, and it’s expected to be weak.
During these conditions, the jet stream tends to become a little bit wavy and takes the storm track farther north into the Pacific Northwest, so the desert southwest tends to be drier, according to Meyer. He noted that’s a sweeping generalization and Utah isn’t usually affected by what the rotating El Niño-La Niña cycle is doing — making it hard to predict the winter.
“During La Niña we can expect a great likelihood that the far southern portions of the state will be drier than normal and at times that can leak up and influence the central and potentially northern Utah conditions. But when we look historically … there are just as many years that look familiar in terms of that predictability as there are years that look opposite of that,” Meyer said.
The official messaging of the Utah Climate Center is that the combination of phases, cycles and weather patterns present a higher likelihood of conditions being normal to somewhat above normal compared to last year. However, that doesn’t preclude the possibility of a slightly underperforming winter, either.
Atmospheric river events will be key in establishing how strong the ski season is. The storms can switch the trajectory of the entire ski season in just a matter of days.
“If they skip over Utah, if they go around, we can have a bust year where many areas around us look valid like they’ve had very favorable wintertime conditions,” he said.
So, Meyer is focused on the next three months which will determine how much soil moisture can be preserved before heading into the snow accumulation season. There’s not a strong relationship between summer conditions and what will happen with winter weather patterns, but there is a carryover in terms of efficiency in the melting of the snowpack.
Meyer is hoping for a steady dose of fall storms and cold fronts to keep temperatures cool and prevent water from evaporating, helping to preserve as much moisture as possible once the summer rains have stopped.
Autumn is important to ensure the ground locks up as much soil moisture as possible, setting the stage for a positive spring runoff and efficient snow melt. Moisture that’s present when the ground freezes in will stay present throughout the winter until the melting occurs. Then, the water runs through the river systems and recharges the reservoirs.
Meyer said there’s been a trend in recent years where the soil has tended to “sponge up” a lot of the snow melt in the spring when drought conditions are amplified, even if there’s a decent snowpack in place. This prevents the water from flowing to where it’s intended to go.
October presents opportunities for early, and sometimes extreme, precipitation as the time when the climatological season of snowfall can begin. At the same time, fall is also becoming drier and the onset date for snowfall is retreating farther into the season.
Meyer said in recent years the first snowfall in some parts of the state, particularly in lower elevations, has been pushed back into mid to late December. Higher elevations are less affected by the trend and tend to have a more steady accumulation.
But in terms of winter recreation, the overall quality of snow is not as good as it used to be. There’s been a general reduction in the snowpack across the state since the 1980s, and the background signal experts are seeing play out is not one of optimism in terms of winter conditions and snowpack, according to Meyer.
“We’ve seen a rather seismic shift in Utah’s winter conditions over the last 40 years and we expect that to continue to play out over the coming decades, and in some cases, in more egregious ways as the region continues to warm and we’re seeing a change in the types of winter storms we’re getting,” he said.
Forecasts are still a month or two away from having a more accurate pattern for how the wintertime will shape up.