If you have flexibility in your schedule and want to find the best snow, I’ve found that 10-day forecasts provide a useful guide to the general timing and location of the next storm. By the time the storm is 3-5 days away, many snowfall predictions are good enough that you can use them to reliably plan your next powder day.
However, what if you don’t have much flexibility in your schedule? Can you use a 6-month winter outlook to plan where the most snow will fall during this upcoming season? Unfortunately, I wouldn’t recommend it. During the last decade that I’ve been professionally forecasting snowfall, I haven’t seen any organization provide consistently accurate long-range forecasts for snow over the winter season.
There are a few exceptions to this rule, though. A strong La Nina, with cooler water in the central Pacific Ocean, or a strong El Nino with warmer water in the central Pacific Ocean, can have a somewhat predictable impact on winter snowfall. The central Pacific Ocean is so large that when the water temperature is well above or below average, it impacts weather patterns across the globe.
A strong La Nina usually means more snowfall over the northern 1/3rd of the United States, and a strong El Nino usually means more snowfall over the southern 1/3rd of the United States. So, is it going to be a La Nina or El Nino this winter?
Actually, there’s a third option nicknamed “La Nada”, which means about normal water temperatures in the central Pacific Ocean. And this is what we will likely see for the upcoming winter. When La Nada is here, it means that we have no reliable clues about the dominant storm track over the United States. This map shows the average storm tracks during a La Nada winter, and as you can tell, they’re all over the place.
Putting all of this together leads to the mundane conclusion that the most reliable prediction for the winter is “average.” I know this doesn’t help your planning very much, but it’s the extent of what the science of meteorology can offer when it comes to seasonal predictions. For another take, read this post by meteorologist Dr. Jim Steenburgh who analyzes the outlook specifically for Utah (and comes to the same conclusion reached here).
Despite the uncertainty of seasonal forecasts, remember that shorter-term forecasts are rather reliable, especially inside of five days. So keep an eye out for that next storm, and have a great season!