Despite warmer trends, snowpack in Colorado is above normal early in the season

With above-average fall temperatures, snowpack in Colorado is above normal.

Snowpack, also called snow-water equivalent, is a measure of how much liquid water is contained in the state's snowfields – a key indicator of drought conditions and seasonal runoff.

As of Friday, Nov. 1, statewide snowpack was at 143% of the 30-year median, which is considered the historical normal, according to the Natural Resources Conservation Service.

Still, Colorado still has a long way to go before experts know how this season's snowpack will compare to previous years. Snowpack buildup typically begins in mid-October and peaks in early April.

“Like in football, we’re early in the first quarter. … There's a lot of season ahead of us,” said Matthew Aleksa, forecaster for the National Weather Service in Grand Junction. “But we’re off to a good start.”

Recent storms have brought cooler weather to mountain and western slope areas, where some places experienced temperatures about 15 degrees above normal in the first half of October, Aleksa said. The bulk of the snowfall was concentrated in the San Juans region, which brought between 1 and 2 feet of fresh powder in the two most recent storms in late October.

Snowpack in river basins in this area is well above 200% of normal, helping to increase the state's total. But in the eastern part of the state, persistent dry weather has hampered snowpack.

In the South Platte River Basin, which stretches along the Front Range from Fort Collins down to Castle Rock, snowpack was at 43% of normal on Friday. The level was at 84% in the Arkansas River Basin, which spans the south-central part of the state.

However, looking at statewide data, “we're pretty close to where we should normally be at this time of year, maybe even a little bit above,” Aleksa said.

But that can change quickly depending on storm patterns, and even a short period of drier weather can cause the snowpack to drop.

“The benefit of the last few (storm) systems is that they helped bring our temperatures down from well above normal to near or even slightly below normal,” Aleksa said. “Needless to say, late this weekend and into next week it looks like we will see more mountain snow and cooler conditions… (and) these new systems are helping to increase the cold air and keep temperatures lower. “

Forecasts from OpenSnow.com show a fairly active start to November, with the next storm arriving sometime Sunday afternoon. About 8 inches of snowfall could be possible near and east of the Continental Divide, but areas west of Berthoud Pass could also see similar numbers.

In a blog post on FridayOpenSnow founding meteorologist Joel Gratz wrote: “The longer-term outlook is all good news.” Some early seasons are warm, leaving us waiting for winter, but it looks like we'll be in for a few storms in the first half of November per week sitting in the storm train.”

The Climate Prediction Center's one-month outlook for November shows equal opportunities that Colorado will experience above or below average temperatures and precipitation. The three-month forecast for November, December and January shows there is a slight chance of above normal temperatures and below normal precipitation in mountainous areas of Colorado.

With recent storms affecting the southwestern corner of the state, Aleksa said patterns could shift toward the central and northern mountains as La Nina conditions continue to develop.

La Nina is an atmospheric pattern determined by temperature changes in the equatorial Pacific and is generally characterized by steeper, cooler weather in the north and drier, warmer weather in the south. The opposite pattern, El Niño, was observed during the 2023-24 winter season, which may have the opposite effect.

None of these patterns have historically had a strong impact on Colorado's snow season, but it is possible that there could be some impact later in the winter.

“It seems like there is more snow in the southern mountains right now,” Aleksa said. “But that could change at the start of the new year when more can be seen in the northern mountains.”