El Niño Brings Deep Snow to PNW: Winter Projection Interpretations by a Washington Ski Guide

By Mark Allen

It only takes one dusting of snow before we start hearing about what is and isn't going to happen this winter. My goal is to temper current forecast interpretations and offer local PNW backcountry skiers and splitboarders a Washington Ski Guide's perspective on El Niño.

You've probably already checked out the seasonal snowfall projections from the NOAA Weather Prediction Center for this winter. A quick glance might deliver some less-than-ideal news for those of us craving powder. Phrases like "warmer than average" or "drier than normal" can easily trigger a premature bout of pre-season blues. But hold off on those travel plans to Colorado for now – I have a different perspective that might reignite your excitement for your local backcountry terrain in the Washington Cascades.

Let's start with a summary of NOAA's regional winter 2023-2024 predictions for the PNW.

“everything is going to be okay. A Cascade winter is going to happen, and it might even be epic.”

NOAA Weather Prediction Center forEcast for winter 2023-24 after a strong measurable El Niño set up of Ocean temps at the equator.


At first glance, NOAA's outlook for this winter season is an unfavorable read for a skier. NOAA's projection shows an enhanced southern jet stream, increasing our region's odds of above-average temperatures and a drier climate in the PNW. Many have summarized it by saying El Niño equates to "Warm and Dry" [3]. To make matters worse, many media outlets are running this as the headline. But the devil is in the details, and within those details, there are rays of hope shining through this report. It might be surprising to read, but everything is going to be okay. Winter is going to happen, and it might even be epic. Having read dozens of these reports, I have learned that winter conditions projections are important but blunt instruments. If we adapt and use them, they can help indicate our local conditions. When you start delving into the NOAA model for this season's prediction, then refer to past El Niño years, and review local snow telemetry data from the same seasons, the picture becomes a little brighter. Let's take a closer look at the NOAA forecast and other important numbers to gain some insight.

“El Niño data shows less of an affect on precipitation as much as it does on temperature. Milder temperatures are the key input for [event] historically” Dallas Glass - NWAC Dep. Director

 

Historic Cascade El Niño Events

El Niño occurrences recorded by Pacific Marine Environmental Laboratory.


I use Snoqualmie Pass as the canary in the coal mine. Snoqualmie Pass is one of the lowest elevation zones where backcountry skiers and snowboarders ride in the PNW, and the data goes back to January 1930. I'm most interested in the Snoqualmie Pass dataset because it should reflect zones with a higher potential to be affected by the warm temperatures brought on by El Niño events in the Cascades. We have great resolution using a wonderful NWAC visualization tool and reference DOT historical snow-depth data. One can quickly cross-reference past El Niño years and review the seasonal snow depths in that local area. The data I focused on was the accumulation of snow. In order to have snow totals, winter temperatures are implied. Anyone can apply a similar review to their home zone. You might discover a micro-climate effect in your local area.

So, let's begin. It is believed that there have been at least 30 El Niño events since 1900 with varying degrees of severity, with the strongest events on record being the winters of 1983, 1998, and 2016 [1]. These three will be the seasons we sample at Snoqualmie Pass.


Matching NOAA and Snoqualmie Pass DOT Data

 

The 1983 El Niño Snoqualmie Pass Telemitry data shows that on January 1st the snow depth was 71 inches and was 134% above the 53 inch all time seasonal average. The remainder of the powder friendly months hovered at 80-90% of average snowfall due to consistent snow accumulation in late January and well into February. [5]

In order to learn what the snow accumulation was like during El Niño years, I cross-referenced the three most notable El Niño occurrences on record with data from the Pacific Marine Environmental Laboratory [1][2] and the Snoqualmie Pass DOT telemetry sites [5] during the peak El Niño winters. The results told a different story than the headlines. After reviewing the data, my initial alarm from reading national headlines about unfavorable projections was diffused. For the powder loving months all three major El Niño events brought seasonal snow totals above or close to matching the all-time seasonal average. To further emphasize this point, there were several epic weeks of atmospheric rivers delivering deep powder skiing in December, January, and February during the strongest El Niño patterns in my lifetime.

Pin Pointing the Outlook

So how is this possible when projections are so bleak? Could that happen this year? To answer this, we need to look closer at the NOAA Weather Prediction Center El Niño model. I use the NOAA Three-Month Outlook - Interactive Tool for the months of Dec-Jan-Feb 2023-2024 [4]. This tool allows one to pinpoint Snoqualmie Pass backcountry in the prediction. You can see that Snoqualmie Pass is located on the outer edge of the forecasted dry zones affected by El Niño. For the powder-loving months, the model projection suggests that Snoqualmie Pass daily high temperatures will be just a hair above freezing, and the daily low temperatures at Snoqualmie Pass will be at a very accommodating winter temperature of 25°F. I don't know about you, but 25°F powder is pretty darn fun, and I'll take free refills all day. The predicted precipitation amounts in the forecast model land squarely on average. This is good because an average season in the Cascades serves up a good season.

The 2016 El Niño Snoqualmie Pass telemetry data shows that January 1st  the snow-depth was 77 inches and is 145% above the 53 inch all time seasonal average. Further, snow in December came on heavy with consistent accumulation over a 30-day period. The season leveled off for February and finished with a significant pulse March.[5]

Checking in with NWAC

So I asked Dallas Glass, Deputy Director of the Northwest Avalanche Center, and Dennis D'Amico, NWAC Forecast Director, if I was looking at this all wrong. Dallas reminded me that the data set samples of the three strongest El Niños may not go back far enough, and there have been at least 30 El Niño episodes recorded. Dallas stated, "But you are right. El Niño data shows less of an effect on precipitation as much as it does on temperature. Milder temperatures are the key input for El Niño historically." [6] Dennis backed up Dallas’s sentiment, saying, "The takeaway from the past was that warmer than normal conditions were a very good bet in moderate/strong El Niño years." However, Dennis went on to say, "Precipitation signals were messier. Even in the strong El Niños with below-normal precipitation, there were 'above-average days of recorded precipitation.'“ Both forecasters reminded me, "While the El Niño metrics might be the same as 50 years ago, our planet is not the same. Like the highest global sea-surface temperatures on record for starters." To add to that, we have had three La Niña events back to back, potentially tempering the warming effects of a new climate. This year's El Niño could truly be the unwanted kid on the block and grumpier than his next of kin. We are about to find out.

The 1998 El Niño the Snoqualmie Pass telemetry data shows that January 1st the snow depth was 37 inches and was 70% of the 53 inch all time seasonal average. That being said the next 15-days would accumulate over 53” bringing the snow totals to 137% above seasonal averages and the remainder of the winter was nearly lock step with the recorded all time average.[5]

the NOAA Three Month Outlook - Interactive Tool indicates the high for Snoqualmie Pass to have an average High of 35F and and average low of 25 for the 3-month period. This is a average of all the peaks and valleys for the entire period.

Conclusion from a Cascades Ski Guide

I was pretty excited to see my hunches about El Niño not being a cause for major alarm supported in the data, at least for winter recreation. I can't even recall which epic winter belonged to El Niño or La Niña. It's always good to look back at the record before following headline lemmings off the cliff. I find that our impressions of weather are rarely accurate and hinge on some other memory. But if I haven't convinced you yet, let me explain where I believe the issues lie when interpreting seasonal projections. These seasonal forecasts were not created for predicting how epic of a ski season is slated to be in the Cascades. They are highly sophisticated tools developed by the nation's leading atmospheric scientists for the purpose of informing people and institutions on how to best prepare with respect to infrastructure, agriculture, and the risk of property. The majority of funding for Washington's mountain weather stations is unrelated to the goal of forecasting for skiing or snowboarding. The backcountry community is merely a new audience that has access to these amazing resources to inform their own priorities. This leaves us with a little extra legwork to dig deeper and apply the data. As skiers and snowboarders, we care mostly about December through mid-March and the upper elevation mountain areas. These reports are for the entire region and are primarily intended to inform interested parties about snow accumulations for agricultural snowpack storage and seasonal flooding risk throughout the entire snowpack's life.

As powder-loving backcountry travelers, we have the benefit of seeking higher elevation terrain, mitigating unfavorably warm conditions. However, storms clearly come in cold enough during El Niño events to bring snow to our lowest backcountry ski areas. I'm not saying it's not going to rain on the snow this season. In fact, I'm pretty sure it's going to. But what I do know is that warm storms in the PNW hold a lot of water content. The data shows that during the three most intense El Niño events, there have been seriously intense periods of snow accumulation in the Cascades. The data also shows a few dry spells have persisted as well. However, what the data does not tell a story of a total winter bust due to the El Niño effect. In fact, I would argue that you might want to consider getting a second pair of goggles, a maritime Helly Hansen Ski Jacket or that new kit at Cripple Creek.

“Seasonal forecasts are just that - the skill in these forecasts is over months and does not reflect the blow by blow of daily weather” Dennis D'Amico-NWAC Forecast Director

 

Ski Guides of the Mountain Bureau are proposing:

 

Final Thoughts

Anecdotally, as a Washington native, I don't attach much emotion to the El Niño/La Niña projections when it comes to recreational snow conditions. Getting me pumped for the winter is not the purpose of the NOAA projection. However, it's a great tool to gain insight into how the shift in the jet stream can explain climatic patterns in our region. We need to recalibrate the projection with real historical data. It seems that after the first few big storm cycles in December, our collective consciousness forgets the unfavorable projection as long as the snow keeps falling. Once we've had enough powder days to reach a certain level of satisfaction, we call it a "good winter." And for skiers, it was. More your winter greens had a great growing season too. For farmers in Yakima, WA, the data shows the snowpack rapidly melts more and faster, accurately matching the projection.

I believe our memory of mountain conditions is pretty unreliable. In fact, our memory is a pretty crummy tool and can often mislead us. I can't seem to recall a major El Niño/La Niña event that was so memorable we remember it in oral history. Indeed, the Cascades have experienced some truly despicable winters in terms of snow accumulation in the mountains. But that unfortunate phenomenon does not have a direct link to the El Niño effect, at least according to our weather sites. We are just going to have to pick-on someone else besides this little guy with a Spanish accent. Relax. It's going to be a great winter. It might even be epic.

 

Mark Allen: IFMGA/AMGA guide and the Lead guide at Mountain Bureau LLC.

About the Author:

Mark Allen is an Washington based IFMGA/AMGA guide and the Lead guide at Mountain Bureau LLC. Born in Northwestern Washington, he has been ice climbing and skiing in the North Cascades for 30 years. Mark’s education in a BS in Geology from WWU, has worked as a Pro Patrol at Crystal Mountain, a professional Observer for Northwest Avalanche Center, a operational forecaster for Northern Alpine Guides and the Mountain Bureau, works on 4 continents as a backcountry ski guide as well as a AIARE Level 1 & 2 Avalanche Instructor as since 2007.



List of Sighted Sources

[1] United States Climate Prediction Center. "Historical El Niño/La Niña episodes (1950–present)".

[2] NOAA El nino home page https://www.pmel.noaa.gov/elnino/what-is-el-nino

[3] NOAA Climate Prediction Center -https://www.cpc.ncep.noaa.gov/

[4] NOAA Climate Prediction Interactive Pin Point Tool https://www.cpc.ncep.noaa.gov/products/predictions/long_range/interactive/index.php

[5] NWAC/ UW Historical Snow Depth Tool https://climate.washington.edu/climate-data/snowdepth/

[6] Phone call with Dallas Glass Northwest Avalanche Center- Deputy Director Oct 24th, 2023

[7] Article review and email with Northwest Avalanche Center Dennis D'Amico-NWAC Forecast Director

 
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