Brains
Scientists at Storm Peak Laboratory in Steamboat Springs, Colorado, analyzed 45 years of snowstorm data to pinpoint what drives Steamboat Resort’s biggest powder days. They conclude that extreme snowfall—those top 5% events—requires a specific atmospheric recipe of cold temperatures, northwest storm tracks, and strong winds.
“These are the days everyone remembers,” Gannet Hallar, Ph.D., director of Storm Peak Lab and professor of atmospheric sciences at the University of Utah, told the Steamboat Pilot. “We found that the biggest powder days happen when storms bring temperatures between -3°F and 10°F, combined with northwest winds up to about 20 miles per hour.”
This unique combination leads to the formation of a specific type of snowflake known as “stellar dendrites.” These are the large, star-shaped flakes that most people picture when they think of perfect powder. According to the National Avalanche Center, stellar dendrites form quickly and are responsible for the low-density, fluffy snow that skiers and snowboarders love. Hallar refers to them as “speedy snowflakes” because they grow rapidly in a short time when conditions are just right.
“The storms that produce Steamboat’s biggest snowfalls tend to approach from a 45-degree angle over the Elkheads and Sleeping Giant before slamming into Mount Werner,” Hallar said. “That terrain, combined with the perfect temperatures and wind speeds, helps create ideal conditions for dendrite formation.”
The study, presented at the Yampa Basin Rendezvous in late May, examined snowfall data from Steamboat Resort dating back to 1979. Hallar and her team, including graduate student Anne Lang, looked at the 95th percentile days of snow accumulation to better understand the driving forces behind them. They also examined how terrain and moisture interact with these weather systems. Key features like the Elkhead Mountains and Elk Mountain (locally known as Sleeping Giant) play a crucial role by creating orographic lift, a process in which moist air is forced upward by the mountains, cooling rapidly and generating snow.
But the scientists also raise a caveat: as global temperatures rise, these near-perfect snowmaking conditions may become increasingly rare. With rising global temperatures, these prime conditions for powder may become less frequent. Lang noted that higher temperatures could shift storm patterns and reduce the number of events that fall within the ideal temperature range for stellar dendrites to form. “One hypothesis is that we’re seeing fewer storms in this range, which could lead to fewer big powder events,” she said.
The research from Storm Peak Lab not only sheds light on what creates Steamboat’s most epic Champagne Powder® days but also highlights how delicate and specific those conditions truly are. As scientists look ahead, there’s growing concern that rising temperatures and shifting weather patterns could disrupt the formula that makes these legendary storms possible. Understanding the science behind snowfall helps skiers appreciate each perfect day on the mountain and reminds us that the future of deep powder may depend on how we respond to a changing climate.
