Despite the warming, early season snowpack in Colorado is above normal

With warmer-than-average fall temperatures, Colorado’s snowpack is rising above normal.

Snowpack, also known as snow water equivalent, is a measure of how much liquid water is held in a state’s snowfields — a key indicator of drought conditions and seasonal runoff.

As of Friday, Nov. 1, the state’s snowpack was 143 percent of the 30-year median, which is considered the historical norm, according to data from the Natural Resources Protection Service.

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Still, Colorado has a long way to go before experts know how this season’s snowpack will compare to previous years. Snow cover usually forms in mid-October and peaks around early April.

“Like in football, we are at the beginning of the first quarter. … We have a lot of season ahead of us,” said Matthew Alexa, forecaster for the National Weather Service in Grand Junction. “But we’re off to a good start.”

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According to Alexa, recent storms have brought cooler weather to the mountain and Western Slope regions, with temperatures in some locations about 15 degrees above normal for the first half of October. The bulk of the snowfall was concentrated in the San Juans region, which mesh is 1 to 2 feet of fresh powder during the two most recent storms that hit in late October.

Snowpack levels in river basins in the area are well over 200% of normal, contributing to the statewide total. However, in the eastern part of the state, persistent dry weather prevented snow cover.

In the South Platte River Basin, which stretches along the Front Range from Fort Collins to Castle Rock, snowpack was 43 percent of normal as of Friday. In the Arkansas River basin, which covers the south-central part of the state, the level was 84%.

Still, looking at the statewide data, “We’re pretty close to where we should normally be this time of year, maybe a little bit higher,” Alexa said.

But that can change quickly depending on the nature of the storm, and even short periods of dry weather can cause snowpack levels to drop dramatically.

“The benefit of the recent (storm) systems is that they have helped bring temperatures down from well above normal to near or even slightly below normal,” Alexa said. “Needless to say, it looks like we’re going to see more mountain snow and cooler conditions later this weekend and into next week … (and) these systems coming in are helping to strengthen that cold air and keep those temperatures cooler.”

OpenSnow.com forecasts show a fairly active start to November, with the next storm arriving sometime Sunday afternoon. About 8 inches of snow could fall near and east of the Continental Divide, though areas as far west as Berthoud Pass could also see similar numbers.

In Friday’s blog postOpenSnow founding meteorologist Joel Gratz wrote: “The longer range forecast is good news. Some early seasons are warm and we’re forced to wait for winter to arrive, but it looks like we’ll be on a storm train into the first half of November with several storms each week.”

Monthly forecast of the Center for Climate Forecasts for November shows equal odds that temperatures and precipitation in Colorado will be above or below normal. Its three-month forecast for November, December and January shows a slim chance of seeing above-normal temperatures and below-normal precipitation in Colorado’s mountains.

With recent storms favoring the southwestern part of the state, Alexa said trends could shift toward the central and northern mountains as La Niña conditions continue to develop.

Atmospheric pattern Due to temperature changes in the equatorial Pacific Ocean, La Niña is typically characterized by wetter, cooler weather in the north and drier, warmer weather in the south. During the winter season of 2023-24, the opposite pattern, El Nino, was observed, which may have the opposite effect.

Neither pattern has historically had a strong impact on Colorado’s snow season, but it’s possible that some effects may occur later in the winter.

“Looks like there’s more snow in the southern mountains now,” Alexa said. “But that could change early in the new year when the northern mountains see more.”