Here is the latest update on the upcoming winter 2012-13 forecast, as shared by our friends at www.aspenweather.net. It’s sounding like it’s going to be a good ski season in Aspen & Snowmass (but isn’t it always?)
There is pretty much a ZERO percent chance that next winter will be a La Nina winter. The going trends right now all favor that we are going to experience an El Nino winter. The water out in the equatorial pacific has been getting warmer and warmer since April. The water is very balmy off of Equador and Chile and is as much as 1.5C above normal already. Out in the central equatorial pacific, sea surface temperatures are .5 to .9C above normal. These trends highly favor El Nino conditions this fall and during the northern hemisphere winter.
We have another big factor to consider for this winter and that is the PDO. The PDO stands for Pacific Decadal Oscillation. In 2008, we entered the cold phase of the PDO. The Cold Phase of the PDO is simply a phase where water temperatures from the Baja all the way up the United States Pacific coast and extending into the north pacific including Alaska are below normal. The PDO is stable and usually lasts for many decades at a time.
So my friends, we now know two extremely important things about next winter. We are going to have an El Nino winter combined with the cold phase of the PDO. This is where the research comes into play. To get an idea of what will happen this winter, we have to go back and look at the past and see what happened in other winters where we had an El Nino and the cold phase of the PDO. This is precisely what I have done. Let me also add this statement to the mix as it is very important. The weather repeats itself!! It is very possible to go back and look at the past based on what is happening now and come up with a very good forecast. Last winter was extremely weird and this technique did not work. Last winter my outlook was wrong for the first time in I don’t know how many years. Probably 15 at least. So the moral of the story is you go with what produces success. Correlating current trends with what has happened in the past produces success because the weather repeats itself!!!
So here’s the deal my friends. There are 9 cases since 1934 that we have had an El Nino winter combined with the cold phase of the PDO. I looked at all these cases in detail and compared them to what is happening right now in the real world. There are two winters among the 9 that stand out very clearly above the rest in terms of matching our current conditions. Those two cases are the winters of 1951-1952 and 2009-2010. So basically I did some statistical stuff involving all 9 cases with more emphasis given to the winters of 1951-1952 and 2009-2010. What that means in english is this, the snowfall and temperatures that occurred in 1951-1952 and 2009-2010 were given more weight when coming up with the final numbers for this winter. There are also some very detailed and well written research papers out there that have studied El Nino winters and the cold phase of the PDO. I also gave a little more weight to the findings that were revealed in those research papers.
So here are the results. I’m actually quite optimistic about the results and I also have a fair amount of confidence in the forecast. I think next winter brings snowfall amounts that are normal to 5 to 10% above normal. This is good news when you compare this forecast to the dismal winter that occurred last year. In terms of temperatures, I think next winter brings normal to slightly below normal temperatures as a whole. In mid August, I will give Y’all some snowfall numbers for in town and at the resorts. Overall, at this point I feel good about the upcoming winter and I’m not expecting a repeat performance of last winter.