Estimated read time: 4-5 minutes
- Utah's meteorological winter begins with uncertainty, as long-range forecasts show equal chances for wet, dry, or normal precipitation.
- La Niña's influence is minimal in Utah, with past winters showing varied precipitation outcomes, highlighting the significance of jet stream patterns.
- Utah's reservoirs are nearly three-fourths full, providing a buffer against potential dry conditions, while conservation remains crucial for water security.
SALT LAKE CITY — Despite a warm and dry start to the season, Utah's statewide snowpack ended meteorological fall slightly above average with 2.8 inches of snow water equivalent.
However, meteorological fall typically produces hors d'oeuvres when compared to meteorological winter, Utah's main snowpack course. About two-thirds of Utah's mountain snowpack — a calculation of water in fallen snow — falls between the beginning of December and the end of February.
That's according to the Natural Resources Conservation Service's 30-year median average of data collected from 1991 through 2020. Since about 95% of Utah's water supply comes from the snowpack collection and spring runoff process, the success of meteorological winter often makes or breaks any given water year.
"That's when we get our most amount of snow, so it's very significant," says Candice Hasenyager, director of the Utah Division of Water Resources, talking about the season that began on Sunday.
A good winter also matters for snow recreation outdoors, but what's in store this winter remains a bit of a mystery as long-range forecasts offer no clear signal when it comes to precipitation. That's par for the course, though, with the conditions setting up over the Pacific Ocean.
Utah's winter outlook
The National Weather Service's Climate Prediction Center updated its La Niña watch last month, noting that there was about a 57% chance that the oceanic pattern would emerge by the end of this year and last through the first quarter of 2025.
Above-normal trade winds blow warm Pacific Ocean water west, allowing cooler water to resurface in the eastern Pacific during a La Niña pattern, as noted by the National Oceanic and Atmospheric Administration. This typically causes the winter jet stream to move north, often creating a track that sends winter storms through Alaska, the Pacific Northwest and the upper Midwest as systems move east.
Meanwhile, warmer and drier conditions generally set up across the southern U.S. during a La Niña pattern.
This also shows up in the prediction center's final outlook for meteorological winter, where most of the upper West and Great Lakes regions are listed as having the highest precipitation probabilities this winter. The Southwest through the Southeast have higher probabilities for drier conditions.
Utah, however, is less influenced by La Niña — or El Niño — than other states. Both oceanic patterns tend to help or hurt areas north and south of the Beehive State, while Utah tends to get a wide range of winters that are good, bad or somewhere in between. It all comes down to where the jet stream forms.
Its last three La Niña winters — 2020-21, 2021-22, and 2022-23 — are perfect examples of this. Utah only received 2.34 inches of precipitation statewide during the 2020-21 winter, which was its 18th-driest meteorological winter dating back to 1895, per federal climate data. The following season was also below normal but closer to normal.
Then in the 2022-23 winter, Utah received 5.78 inches statewide — its ninth wettest winter on record. That same water year, boosted by a jet steam that kept pushing storms through Utah, also produced the state's largest snowpack on record. It was was larger than the 2020-21 and 2021-22 water years combined.
Long-range forecasts for the next three months reflect this uncertainty. Most of Utah is listed as having "equal chances," meaning there's about an equal probability that Utah ends up with a wetter, drier or near-normal precipitation this winter. Southern Utah has a slightly higher probability of below-normal precipitation.
Most of the state has a slightly higher probability for above-normal temperatures over the next three months. Only a sliver of northern Utah is listed as having equal temperature odds.
Utah's water savings account
Hasenyager told KSL.com that she's holding out hope, but the state has a saving grace in its reservoirs right now. Utah's reservoir system entered December nearly three-fourths full, which is about where it was this time last year. It's also 20 percentage points ahead of the winter median after back-to-back above-normal snowpack and lower consumption averages in recent years.
That gives Utah's water reserves a boost in case the state endures another bad season.
"They're our bank account. They help us to extend over periods where we have less than optimal snowpack and less than optimal runoff," Hasenyager said. "We're hoping for a big year, as always. But if for some reason we don't, it's nice to have the reservoir (capacity) available."
She adds that ways to reduce water consumption are still recommended in case there is a bad winter followed by more drought in the summer. However, another good winter would mean another boost for the Great Salt Lake and Lake Powell, two large bodies of water that remain well below full capacity after major drops during the two-decadeslong "megadrought." Both have benefitted from controlled releases out of reservoirs to combat flooding concerns.
Gov. Spencer Cox said Monday that he believes that the Great Salt Lake could even move toward "healthy territory" by next spring should the Great Salt Lake Basin have another good snowpack collection.
"We're hopeful to have a good year," he said. "Regardless of whether we have another great year, a mediocre year or a terrible year, we're in better shape than we've been in many years because of (conservation efforts)."
