What is the influence of El Niño on the winter in the Alps?

meteomorris

Will it be snowy or dry?

Farmers fear crop failure. California is facing a wet winter. The years 2015 and 2016 will be the warmest ever and according to this French meteorologist this El Niño will make history. Everybody is excited. We're going to have to deal with an El Niño we've never experienced before. But what is the influence of El Niño on the winter and snowfall in the Alps? 

Will El Niño bring us this? 

Or this?

What is El Niño?
A strong rise of the temperature of the water in the eastern Pacific Ocean off the coast of Peru is observed every few years. This phenomenon is called El Niño. This strong rise of temperature of the water in the ocean disrupts the pattern of warm and cold ocean currents and affects the weather worldwide. This process is repeated every three to seven years, where there are weaker and stronger versions of an El Niño.

Since 1950 the El Niño are mapped where two events are worth mentioning here. First, the so-called double El Niño between '86 and '88. And of course, those of winter '97 -'98. The strongest variant that we have observed since the measurements. Below you can see the El Niño which we have seen since 1950.
El Niño's and la El Niña's since 1950 (bron: NOAA)

The current El Niño
The phenomenon we are dealing with now is something special. It is both a double El Niño (as we know from winter '86 -'87 and '87 -'88) and on the other hand it is one of the strongest El Niños since we make measurements. And that makes it confusing. What should we have a look at? The data and details about double El Niños or to the data from the strong El Niño of the nineties? Both are merely isolated events that we have not previously mapped and thus it is difficult to apply lessons from the past here.

Global implications for the snow
But since measurements about 11 moderate to strong El Niño events occurred and now science has a reasonable picture of global consequences for ski resorts, which is roughly the following:

  • Drier and warmer than normal in Alaska, Canada and the PNW (Mt. Baker etc.)
  • Wetter and often colder in southern Utah, Arizona, New Mexico and southern Colorado.
  • Warmer than normal on the main island of Japan (Honshu)

And that looks like this:

The influence of El Niño on a global scale

The Alps aren't included in the list and on the map above. Is there no correlation between El Niño and snow in the Alps? Or have the Alps been overlooked? Actually, there is no proven correlation till now, let alone a causal link between El Niño and the weather in the Alps. There is only one study from The Netherlands showing that El Niño will result in a wet spring in western and middle Europe. That's one positive point for the northern Alps.

There is no more data?
I started to look for sources and studies and encountered a lot of BS. You start to google and you find a lot of results, but the evidence of those articles is rather thin, if not non existent. Fantasy weather man and fortune tellers trying to predict the weather. Anyway, I've also found some really interesting data, that was actually evidence based. 

Below you will find the snow maps of Switzerland and France. These are maps on which the snowfall of the complete winter is compared with the average snowfall. I have plotted the maps on the El Ninos of recent years and guess what? There are El Niño years when there is more snowfall than average in the Alps and there are El Niño years when there is less snowfall than average. 

Let's have a look at the maps again. Red is less snow than normal, blue is more snow than normal.Snowfall in Switzerland during El Niño events (Source: wePowder/meteosuisse)

Below the snow maps for the French Alps. On top you'll see the resorts close to the Mont Blanc and on the bottom the resorts where the mountains are overlooking the Mediterranean. Blue is more snow than usual and red is less snow than usual. Interesting data, but no recognizable relationship with El Niño.

Snowfall in France during El Niño events (Source: wePowder/meteo France)

Conclusion
The conclusion is that we should exclude El Niño as a parameter in our forecast for the weather in the Alps this winter. There simply is no correlation to be discovered between El Niño and snow in the Alps. Although ... that one study that showed that spring will be wetter than normal is interesting. If I had to choose between a pre-booked holiday for Christmas or Easter, then I would opt for Easter. But that's based on my personal experiences, I always had great snow during Easter. 

Have a great winter!

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