Ten centimeters of snowfall is expected in the mountains of the Aspen area on Monday

Aspen can expect a brief respite of sunshine and warmer weather Monday as a fast-moving storm moves through, but snow accumulation will be modest compared to the significant snowfall that led to Thanksgiving.

Tom Renwick, a meteorologist with the National Weather Service in Grand Junction, forecast five centimeters of snow in the city and about four centimeters at higher elevations. The storm is expected to subside by Tuesday morning.

Renwick is cautious about predicting significant rainfall in the near future.

“I wish I had better news about impending storms, but all we’re showing is a fast-moving storm on Monday that will be over by Tuesday morning,” he said.

He added that current forecasts for Aspen and the Central Mountains are leaning toward a drier pattern, although conditions could change.

“The Climate Prediction Center (CPC) says the entire desert southwest, including the central mountains of Colorado, will be dry this winter,” he said. “They said that over the summer too and we all know how that went. I’m keeping my fingers crossed that they’re wrong again.”

Aspen experienced above-average rainfall this summer despite previous drought forecasts. However, he noted that La Niña winters typically tend to be drier.

“La Niña tends to lead to drier winters, but after living here for a while I’ve noticed that right after New Year’s it really kicks into high gear as far as humidity goes,” Renwick said. “This has nothing to do with any predictions; That was just my experience in those years.”

La Niña, defined by cooler than average sea surface temperatures in the central and eastern Pacific, often influences weather patterns by shifting the jet stream northward. This pattern typically results in more precipitation in the Pacific Northwest and drier conditions in the southern United States, with Colorado in between.

A weak La Niña is expected for the 2024-2025 winter season. The National Oceanic and Atmospheric Administration (NOAA) is forecasting drier-than-average conditions for much of the Great Plains and southern Rockies, while northern Colorado will see near-normal to slightly below-average snowfall. Aspen has experienced both above- and below-average snow amounts over the past five La Niña seasons.

Renwick remains optimistic, citing the unpredictability of winter weather. He noted that atmospheric rivers that brought heavy snowfall to the area just over a week ago have the potential to disrupt the dry La Niña pattern.

He said there’s a chance the area could see more of these systems move this winter – but not anytime soon.

“There may be a small system the following weekend after Monday’s storm, but it will be very small,” he said. “Normally, atmospheric rivers will result in above-average snowfall in a dry La Niña year, but we have not experienced anything like this before.”

Atmospheric rivers are narrow bands of concentrated moisture that can transport precipitation directly from the Pacific Ocean to Colorado, sometimes overriding the typical dry influence of La Niña and the shift of the northern jet stream. While none of these are currently in the forecast, they remain a wild card in the forecast for this winter.

Renwick emphasized that it’s technically not even winter yet, which gives room for hope.

“I remain optimistic about snow levels for this winter season,” he said.