Autumn has arrived in the high country with trees swapping their summer greenery for the yellow and auburn hues of fall. The days are growing shorter, and a nip of cold hangs in the air. High in the craggy peaks of the La Platas and San Juans, the first snow has started to appear.
Every day brings winterlike weather a little closer. Raja Bradford-Lefebvre, who grew up in Silverton and was working with her dad Tuesday morning, found a white coating on the highest peaks of the San Juans.
“Looks like a dusting of snow somewhere around 10,500 feet and up,” Bradford-Lefebvre said. “Not enough to ski just yet, but soon!”
The first major snowfall is still at least a couple weeks away, said Lucas Boyer, meteorologist with the National Weather Service.
“We might see a few flurries,” Boyer said. “But accumulations are going to be pretty weak.”
Boyer said as the Northern Hemisphere transitions from summer to fall, warm temperatures will likely linger. Even if the air is cold enough for snow, the ground will remain warm – meaning any flakes that fall will likely melt soon after hitting the ground.
“You got to get freezing to produce snow, and that’s a little less of a stretch, especially in the mountains,” Boyer said. “As far as sticking to the ground, it’s going to be pretty much gone as it falls.”
Regardless, the first snows of the year have arrived. How this modest shift toward colder weather factors into the long-term winter forecast is hard to interpret. Boyer said it’s important to remain patient and take seasonal outlooks with a grain of salt.
“A lot of winter and seasonal forecasters try to get into the tea leaves,” Boyer said. “Typically, there are some behavioral patterns that happen. But as far as pinning a winter on if an El Niño or La Niña occurs, it is a tight wire that those of us in the daily forecasting business try not to get into too much.”
Multiple long-term forecasts like the Farmer’s Almanac and Open Snow attempt to predict how a winter will unfold based on indicators like the El Niño-Southern Oscillation pattern. This pattern indicates whether a winter will be a La Niña or El Niño year – which affects the location of the jet stream across the northern or southern portion of the hemisphere based on surface temperatures in the Pacific Ocean and, as a result, which regions are most impacted by winter storms.
“There is a 20% chance potentially of La Niña,” Boyer said. “But yeah, we’ll have to wait and see. It’s just really tricky to pin localized weather on those big oceanic-scale weather patterns.”
Still, Boyer said long-term forecasts can be compared to past winters with similar weather conditions. For instance, the winter of 2022-23 was one of the snowiest in recent memory, despite being a La Niña year, according to the Natural Resources Conservation Service.
Those conditions typically push the jet stream to the north, often leading to drier winters in the Southwest U.S. However, La Niña years generally bring warmer atmospheric conditions, allowing more water to evaporate off the ocean and fall as snow in the southern mountains – like what happened in 2022-23.
“There are consistencies in these weather patterns,” Boyer said. “But deeper into those you'll see inconsistencies by each winter.”
Boyer said that even if measurable snowfall is still weeks away, now is a good time to start thinking about switching to snow tires and breaking out the snow shovels. He also advised travelers using high-elevation passes like Wolf Creek or Red Mountain to begin factoring snow levels into their travel plans.
“We’re coming off the warm season, and with snow potentially falling on the passes and on the roadways, it’s good to be weather-aware and keep track of those pass level forecasts,” Boyer said. “As far as shifting to seasonal gear, we’re still in September, but by the time we get into October, that’s when we start seeing some accumulating snow. So it’s a gentle remind to have our ducks in a row. Winter is coming.”
sedmondson@durangoherald.com
