The NOAA informed us last week that it expects winter 2019/20 to be ‘neutral’ with regards to El Niño and La Niña, which might be bad news for Colorado mountains, says Colorado State Climatologist Russ Schumacher.
Of course, there are many factors that can influence our mountain snowfall, but a major one is the swing in Pacific Ocean temperatures that produces El Niño and La Niña. El Niño occurs when surface temperatures in the equatorial Pacific are above-average, usually resulting in wet and cool conditions across the southern tier of states, with good snow for Colorado’s southern resorts. La Niña years, when those ocean temperatures are cooler than normal, tend to produce dry, warm conditions in the south, while the Pacific Northwest is wet and cool. That can favor Colorado’s northern resorts, writes The Denver Post.
“It’s probably a safe bet that we’re not going to see another epic snow season like we saw last year,” said Schumacher, director of the Colorado Climate Center at Colorado State University. “Most locations in the mountains tend to be on average a little bit lower than normal snowfall during neutral conditions. There’s a handful of neutral years where you get a lot of snow and a handful where it’s quite dry. In the record that we have, there is more of those dry years than the snowy years in the neutral phase.”
Neutral years also make it harder to predict our winter weather than when El Niño or La Niña influencing it. Just last week higher elevations, including some ski resorts, saw snow, and Trail Ridge Road through Rocky Mountain National Park closed due to snow (and has since reopened). But unfortunately that isn’t a sign of a great winter ahead, or that those resorts can even start making snow now.
“There’s no sign that we’re going into La Nina, so I’m hopeful that we don’t have a repeat of the terrible snow drought of two winters ago,” Schumacher said. “That was La Nina conditions, which, especially for the southern mountains, historically tends to be very dry.”
Last year, an El Niño year, was a big snow year for the majority of Colorado, as well as most areas across North America. February and March brought record snowfall to many areas, including Colorado, and resulted in unprecedented avalanche conditions across the state. Many resorts stayed open later than scheduled, Mammoth in California almost made it to August, and Arapahoe Basin, CO, and Snowbird, UT were skiing on 4th July. Steamboat Springs, CO even saw snow on 22nd June, the lastest they’ve ever received measurable snow.
Whatever happens, we’ll take it. There will be snow for sure, and there will be powder days. We’ll just make sure we make the most of every single one…