We can say goodbye to El Niño and welcome La Niña. This means that the temperature will be a bit lower worldwide and that the northwest of North America can expect cold air and plenty of snow. But what is the meaning of La Niña for the Alps? Will it be colder? Will we have more or less powder days? Will we get more heavy dumps? And where exactly will the snow come down: the northern, southern or the western Alps? These questions might get you stoked for next winter.
From El Niño to La Niña
The El Niño phenomenon, which globally effects the temperatures to rise, decreases in strength. El Niño was caused by a bubble of warm water that is visible off the coast of Peru and that has a lot of influence on the distribution of high and low pressure systems over the Pacific Ocean. But that warm bubble is disappearing and the colder water is showing itself in the most recent measurements. Scientists believe that the chance of a La Niña for this winter is around 75%, so we can get ready for lower temperatures. It's a process that repeats itself every 3 to 7 years in which you'll see strong and weak variations of a La Niña.
The La Niña's are mapped since the 1950's and there are two events worth mentioning here. First, the so-called double La Niña between '98 and '00. And of course those of winter '73 -'74 and '88 -'89, the strongest variations we have observed since the beginning of the measurements. You can check out the measured La Niña's since the 1950's below.
Around nine moderate to strong La Niña events occurred since the beginning of the measurements and now science has a pretty good first impression of the global consequences for skiers and snowboarders. You can expect it to be:
- Colder than normal in Alaska and Canada
- Colder and more precipitation than normal in the PNW (Mt. Baker etc.)
- Dry and higher temperatures in southern Utah, Arizona, New Mexico and the south of Colorado
- Colder than normal on the main island of Japan (Honshu)
And that looks like this:
The Alps aren't mentioned in the list and on the map above. Is there no connection between La Niña and snow in the Alps? Or have the scientists simply overlooked the Alps? Of course they haven't. There simply isn't a proven correlation, let alone a causal connection between La Niña and the weather in the Alps.
Isn't there more data?
Yes, but not that much. A lot is said, but the evidence of all the articles is rather thin. Very thin. Eventually I found something that's worth mentioning. You can see the snow maps of Switzerland and France below. These are maps showing the snowfall of an entire winter compared to last year's average. I have plotted those maps on the La Niña's of the past few years and guess what? There are La Niña years that more snow comes down than normal and there are La Niña years that there is less snow coming down than average. Check out the map from Switzerland below. Red is less snow than usual and blue more snow than usual.
Below you'll see the snow maps of the French Alps with on top the resorts close to the Mont Blanc and on the bottom the resorts where the mountains overlook the Mediterranean. Blue is more snow than usual and red less snow than usual. The maps are quite interesting, but there's no recognizable relationship with La Niña.
The conclusion probably is that we can exclude La Niña as a parameter to do a forecast for next season. No relationship between La Niña and snowfall in the Alps can be found. Although... if you watch the video above you can hear something positive... winters in the UK tend to start earlier than normal (but end earlier than normal as well). More about that in my next update.