For the upcoming winter season, an El Niño looks to be in store, and better yet, current sea surface temperatures are showing a strong El Niño event. This article will explain what exactly El Niño is and what a strong El Niño episode could mean for the 2023-2024 ski season.

What is El Niño?

The term El Niño refers to the large-scale ocean-atmosphere climate phenomenon linked to periodic warming in sea-surface temperatures across the central and east-central equatorial Pacific.

El Niño represents the warm phase of the ENSO cycle and means that the ocean water temperatures are warmer than average.

El Niño Criteria

1) The average sea surface temperatures in the Niño-3.4 region of the equatorial Pacific Ocean were at least 0.5°C (0.9°F) warmer than average in the preceding month.

2) The average anomaly of at least +0.5°C (+0.9°F) has persisted or is expected to persist for 5 consecutive, overlapping 3-month periods.

Current El Niño Status

Confidence is growing that following three consecutive La Niña winters, an El Niño event will take center stage for the 2023-2024 winter season.

An El Niño emerged during the summer of 2023, and long-range models have been projecting a higher-than-average chance of El Niño continuing into the winter of 2023-2024.

The weekly Nino-3.4 region index (sea surface temperatures in the east-central Pacific) anomaly is up to 1.3°C. This is the warmest weekly SST anomaly in August since 2015.

How predictable are the impacts of El Niño?

There are two major sources of uncertainty in long-range forecasts predicting weather months in advance. 

The first source of uncertainty is how accurately we can predict El Niño or La Niña. El Niño is expected to continue, with chances for El Niño increasing to 95% during the December 2023 to February 2024 timeframe.

The second source of uncertainty is the atmospheric response to El Niño or La Niña. That is, if El Niño occurs, does it always affect the weather in North America in the same way?

To determine how El Niño impacts weather in North America, we can look at snowfall records during past El Niño events and compare them to a typical year. 

Historical El Niño Episodes

The map below shows winter snowfall during seven significant El Niño episodes. The higher the number, the stronger the El Niño. The blue dots are above-average, the white dots are average, and the orange dots are below-average snowfall.

The effects of El Niño appear to show a mixed bag for much of the Western US, with the strongest signal being average to above-average snowfall for the Southwest. Again, though, the pattern doesn’t hold 100% of the time.

2015-2016 Winter Season

As mentioned above, the Niño-3.4 region index anomaly as of October 9, 2023, is up to 1.5°C, which is the warmest weekly sea surface temperature anomaly in October since 2015 (1.9°C in 2015 vs. 1.5°C in 2023).

Since the last significant El Niño episode occurred back in 2015, let's have a little fun by looking back at the snowfall during the 2015-2016 winter season at ski resorts across the Western US and Canada.

All data is courtesy of BestSnow.net

California

• Kirkwood: 458" (100%)
• Palisades Tahoe: 491" (108%)
• Mammoth: 358" (102%)

Colorado

• Steamboat: 408" (110%)
• Beaver Creek: 341" (104%)
• Wolf Creek: 443" (114%)

Utah

• Snowbasin: 277" (91%)
• Alta: 438" (86%)
• Brian Head: 301" (96%)

Pacific Northwest

• Crystal Mountain: 520" (128%)
• Mt. Hood: 478" (107%)
• Whistler: 485" (117%)

Northern Rockies

• Whitefish: 317" (98%)
• Jackson Hole: 317" (86%)
• Sun Valley: 213" (112%)

Other Areas

• Big Sky: 274" (97%)
• Whitewater: 412" (105%)
• Taos Ski Valley: 253" (98%)

The 2015-2016 ski season is interesting to look at as a potential comparison for an El Niño episode but keep in mind that no matter how deep or light a winter is overall, when it comes to skiing, it’s all about timing.

Booking a trip 7-10 days in advance and for a general area that looks stormy will increase your chances of scoring the best conditions.

If you're ready to level up your weather app for the upcoming winter season, consider upgrading to OpenSnow All-Access. Whether you’re chasing powder, searching for sunny days, or something in between, our 10-day snow forecasts, expert "Daily Snow" forecasters, and high-resolution weather maps have you covered.

But don't just take my word for it ... "Any weather app can give a mediocre forecast for a mountain town, but only OpenSnow provides a good idea of actual mountain conditions. It's a small price to pay ($29.99/year) for the best weather forecasts." – Real App Review

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Download the free OpenSnow app for the most accurate snow forecast and snow report information and stay tuned to our weather forecasts for the latest updates.

Sam Collentine