La Nina

This year, 2010, is a La Nina year. La Nina and her brother El Nino have long been sources of interest for me. People talk about them like they know them personally and, when you're from the town of Revelstoke, people generally talk about them like they're the God and Goddess of increased snowfall.
La Nina generally makes the winter in western BC cooler and El Nino makes it warmer. This isn't always the case, but it's a good general rule to follow if you're wondering what the effect of La Nina is going to be.
What happens with La Nina is that the trade winds in the Peruvian area of the world start blowing stronger (for reasons I have never known) and this causes more upwelling of deeper ocean water. That deeper water is cooler, and with its emergence the jet stream is modified (weakened) and this causes a global shift in weather for the La Nina period. The effect isn't the same globally, but the change in something as important as the jet stream definitely causes some changes to weather throughout the world.
How this translates to Revelstoke is that we generally get a snowier, colder winter. The difference in temperature is not alarming though for us of the human persuasion: it's about 1 to 2 degrees colder on average.
And what about this year? Will La Nina deliver what the snow sport lovers want? My big decision is that nobody really knows for sure. Definitely not me. I haven't even looked at a weather map.
So far, in December, we don't have epic amounts of the white stuff, but La Nina really shows off her precipitation and coolness from December to February anyway, so it's too soon to tell what the winter snow forecast will be. What I do know for sure is that I'll be with the rest of the people who are hoping for good snow beneath my skis.