A La Niña Watch has been issued because conditions are favorable for the development of La Niña conditions within the next 4 months. We have been in an ENSO-Neutral phase recently which is defined by the surface water temperatures in the equatorial Pacific ocean running near normal compared to long-term average.
Depending on which phase of ENSO (El Niño Southern Oscillation) we are in, it has big implications of what the upcoming winter will be like.
First off, what happens during each ENSO phase?
Since we are anticipating La Niña conditions, we’ll focus on the right side of this image. Normally, high pressure will set up off the west coast of North America. Due to this, the storm track will allow for weather systems to track into British Columbia and the Pacific Northwest. This track will bring active weather into the central and northern Rockies, through the Great Lakes region and into the Northeastern US.
This is the ‘typical’ setup of what generally happens. Of course there can be instances where we have a more southerly tracking storm but that should be the anomaly this upcoming season.
Most mountain ski areas should experience a decent winter based on what is expected when La Niña conditions are present. This does exclude the Sierra Nevada mountains and some of the Southwest mountains in Arizona and New Mexico and southern Colorado.
Globally, weather will be influenced by the cooler waters in the Pacific. Our friends across the pond in Japan could expect cooler conditions and a solid ski season ahead.
Coming back to the mainland – a good way to anticipate how this season will shape up is to look at previous winters where La Niña conditions were also present.
Winter 2008-2009 (a weak La Niña season)
Looking at the accumulated snowfall during the 08/09 winter when there was a weak La Niña present, much of the northern tier of the United States saw ample snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 10-40 feet of snow
The Sierra Nevada of California: 10-30 feet of snow
The Uintah and Wasatch Mountains of Utah: 10-30 feet of snow
The Colorado Rockies: 8-30 feet of snow
The Grand Tetons: 15-50 feet of snow
The Bitterroots of Idaho and Montana: 10-40 feet of snow
The Great Lakes: 8-20 feet of snow
The Green and White mountains of New England: 8-20 feet of snow
The Central and Southern Appalachians: 3-15 feet of snow
The wider ranges of snowfall come with the more intense elevation changes of the western US.
Winter 2010-2011 (a strong La Niña Season)
Looking at the accumulated snowfall during the 10/11 winter when there was a strong La Niña present, much of the northern tier of the United States saw bigtime snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 15-50 feet of snow
The Sierra Nevada of California: 20-50 feet of snow
The Uintah and Wasatch Mountains of Utah: 10-30 feet of snow
The Colorado Rockies: 10-40 feet of snow
The Grand Tetons: 20-50 feet of snow
The Bitterroots of Idaho and Montana: 20-50 feet of snow
The Great Lakes: 6-15 feet of snow
The Green and White mountains of New England: 8-15 feet of snow
The Central and Southern Appalachians: 5-15 feet of snow
Winter 2011-2012 (a moderate La Niña present)
Looking at the accumulated snowfall during the 11/12 winter when there was a moderate La Niña present, much of the northern tier of the United States saw decent snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 15-50 feet of snow
The Sierra Nevada of California: 10-30 feet of snow
The Uintah and Wasatch Mountains of Utah: 8-20 feet of snow
The Colorado Rockies: 10-30 feet of snow
The Grand Tetons: 10-40 feet of snow
The Bitterroots of Idaho and Montana: 10-40 feet of snow
The Great Lakes: 6-15 feet of snow
The Green and White mountains of New England: 4-15 feet of snow
The Central and Southern Appalachians: 1-8 feet of snow
Winter 2016-2017 (a weak La Niña present)
Looking at the accumulated snowfall during the 16/17 winter when there was a weak La Niña present, much of the northern tier of the United States saw great snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 15-50 feet of snow
The Sierra Nevada of California: 120-50 feet of snow
The Uintah and Wasatch Mountains of Utah: 15-40 feet of snow
The Colorado Rockies: 15-40 feet of snow
The Grand Tetons: 20-50 feet of snow
The Bitterroots of Idaho and Montana: 20-50 feet of snow
The Great Lakes: 3-10 feet of snow
The Green and White mountains of New England: 8-15 feet of snow
The Central and Southern Appalachians: 1-6 feet of snow
Winter 2017-2018 (a weak La Niña present)
Looking at the accumulated snowfall during the 17/18 winter when there was a weak La Niña present, much of the northern tier of the United States saw okay snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 10-40 feet of snow
The Sierra Nevada of California: 8-20 feet of snow
The Uintah and Wasatch Mountains of Utah: 8-20 feet of snow
The Colorado Rockies: 10-30 feet of snow
The Grand Tetons: 15-40 feet of snow
The Bitterroots of Idaho and Montana: 20-50 feet of snow
The Great Lakes: 8-20 feet of snow
The Green and White mountains of New England: 8-15 feet of snow
The Central and Southern Appalachians: 2-10 feet of snow
Winter 2020-2021 (a moderate La Niña present)
Looking at the accumulated snowfall during the 20/21 winter when there was a moderate La Niña present, much of the northern tier of the United States saw moderate snow. Here’s a general idea of what each region saw during this winter:
The Cascades of Washington and Oregon: 15-40 feet of snow
The Sierra Nevada of California: 8-20 feet of snow
The Uintah and Wasatch Mountains of Utah: 8-20 feet of snow
The Colorado Rockies: 10-30 feet of snow
The Grand Tetons: 15-30 feet of snow
The Bitterroots of Idaho and Montana: 20-40 feet of snow
The Great Lakes: 3-10 feet of snow
The Green and White mountains of New England: 8-10 feet of snow
The Central and Southern Appalachians: 2-8 feet of snow
Key Takeaways
Overall, the trend of a La Niña winter is to bring ample snows to the Cascades, the northern Rockies and the Tetons. La Niña seasons can bring the Sierra Nevada and the Colorado Rockies hit or miss snows but enough to have a great season and great pow days.
Another factor to note is that when a La Niña winter follows a winter that also had La Niña conditions present, the second winter tends to be less impressive in terms of snowfall totals across the US.
The Climate Prediction Center is forecasting the winter (which runs from December through February) to have above normal precipitation in the Pacific Northwest with drier conditions across the southwest.
As you can note, the Sierra Nevada mountains are including in the possibility of being drier than normal. The Colorado Rockies, the Wasatch, Uintah and Tetons all have an equal shot at seeing above or below normal precipitation.
It’s a sure bet that it’ll snow this winter, obviously but where will the biggest and best snows fall? Likely in the Cascades and Northern Rockies. Time will tell and we’ll be here to update you but for now – do your snow dances and hope that this La Niña winter is one for the record books!
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