What Happened to Our La Nina?
Earlier this year, the NWS issued their winter forecast that called for colder than normal temperatures and higher than normal precipitation. I expressed my doubts about the physical practicality of such a forecast.
Well, that forecast isn’t working out, and the NWS has issued quite a good little summary on what’s happening. It’s definitely more technical than a newspaper article, but it’s certainly not a research article or anything like that. If you’re interested in knowing why our winter has been how it is, this is a really good read!
I still stand by the original forecast not making much sense. As for the near-future, one of my best cold-weather predictors, Vladivostok, Russia, is still relatively warm (only -20°C), so a cold outbreak is probably a long ways off yet.
Handy forecasting trick: Most of the Prairie cold-outbreaks occur when a large ridge slides over the pole from Siberia and then down through Yukon (the Yukon? Any Yukon-ites able to enlighten me?) into the Prairies. When doing medium-term forecasts (8-15 days), I’ll often look at Vladivostok. If they’ve hit below -35°C, then within 6-12 days we’ll often get the cold weather here with daytime highs between -20°C and -25°C. If they get more towards -50°C, then within two weeks the Prairies will have widespread cold temperatures and extreme wind chills.
I still wonder why we bother with seasonal forecasts. Understanding how these oscillations all work is great, but our ability to accurately forecast them individually is often lacking, and we’re a long, long ways off from being able to resolve numerically how all these things interact together. If anything, this just shows how constant analysis and diagnosis of ongoing weather and climate patterns are the best method of forecasting.