Based on historical snowfall data, folks with Mt. Bachelor Ski Area are hopeful an unusual climate event will bring above-average snowfall to the mountains near Bend this winter. But climate scientists say this season’s weather pattern is shaping up to be like nothing we’ve seen before.
All signs point to a “very strong” El Niño event this winter, according to the National Weather Service’s Climate Prediction Center. The phenomenon is caused by warming water near the equator in the Pacific Ocean.
Typically, El Niño events mean warmer, drier weather than normal in the Pacific Northwest.
But counterintuitively, when an El Niño grows strong enough — what’s known as a Super El Niño — the weather pattern is reversed, pushing more storms into the Pacific Northwest.
That’s happened only three times on record: The winters of 1982-1983, 1997-1998 and 2015-2016. Among those years, Mt. Bachelor averaged 427 inches of snowfall — 2 feet more than the annual average, according to a Tuesday blog post on the ski resort’s website.
“To be fair, three seasons is a small sample size, but this data makes me optimistic about the Super El Niño season ahead,” Communications Director Presley Quon wrote.
The snowiest of past Super El Niño winters at Mt. Bachelor was in the early 1980s, when the mountain received 536 inches of snow, more than three times the 2025-26 season’s snowfall, which was historically low across the state. The 1997-1998 Super El Niño season produced 333 inches of snow, according to Quon, which is below average for Mt. Bachelor.
Though observational data points on Super El Niño are sparse, the trend at Mt. Bachelor is supported by broader climate modeling, said Larry O’Neill, the state climatologist for Oregon. To get a better idea of the link between the strength of an El Niño event and precipitation, O’Neill and other researchers ran hundreds of weather simulations based on past data and ocean temperature conditions as part of the 2025 Oregon Climate Assessment.
Under the models, the trend held true: Strong El Niño years usually meant drier winters, but Very Strong El Niño winters were “significantly wetter than normal and comparable to those during Strong La Niñas,” the report reads.
“That is one reason we have a little bit more confidence we’re not seeing a sparseness of data issue,” O’Neill said.
Based on observational data, Super El Niños still produce warmer temperatures, but that can vary between northern and southern Oregon, with southern Oregon sometimes seeing cooler temperatures, according to the assessment.
The catch is that this winter’s El Niño could be unprecedented. There’s a 75% chance this winter’s El Niño will be stronger than any event dating back to 1950, according to the weather service.
“Because it’s unprecedented, we don’t know if that will hold true for this winter as well,” O’Neill said.
“The second caveat is the climate has been changing, and it’s been 10 years since we had a very strong El Niño event,” he added. “In that time, the atmosphere has warmed a certain extent. We’ve seen that warming is making our snowpack unpredictable. Over time, we’ve been getting less mountain snow.”
Oregon’s average annual temperature has warmed three degrees Fahrenheit since the early 20th Century due to human activity, the assessment says.
O’Neill said ocean temperatures in the Pacific that indicate an El Niño have already risen past historical levels, and those temperatures don’t usually peak until December or January.
“We still have about three more months of warming in the Pacific, and we’re already at the warmest that’s ever been measured,” O’Neill told the Source.
“This is likely to blow any previous El Niño off the charts, at least in terms of ocean temperatures,” he added.
Super El Niño events are usually linked to more intense hurricanes in the tropics and flash flooding from heavy rains in western Oregon, O’Neill said.
Those rain events, called “atmospheric rivers,” could put a damper on snowpack if mountain temperatures aren’t cold enough to turn precipitation to snow, O’Neill said.
But climate patterns like El Niño and its counterpart, La Niña, don’t always result in predictable outcomes, O’Neill said.
“We could have a really wide variety of outcomes here,” he said.
MAKE LOCAL JOURNALISM HAPPEN
Republish our articles for free, online or in print, under a Creative Commons license.
