Forecasting the Winter of 2017
With temperatures in the 70's last week and 40's this week, it should be obvious to you that summer is over and Old Man Winter will eventually wake up from hibernation. So, just how harsh will the season be over the next many months?
When forecasting for seasons, one of the most important factors is ocean temperatures. They essentially drive weather patterns. Those ocean temperatures cause an increase or decrease snow amounts, allow for bursts of cold and warm air and drive the severity of each winter season across the Continental United States.
This year, we are in a developing La Nina pattern, which means water temperatures near the equator are cooler than average. Often, this can bring our local area an active pattern.
Warmer waters in the northern Pacific will allow the jet stream to go over Alaska, and then dive southeastward into our region. This allows multiple weather systems to make a direct path to our area. The big question is, when this happens, will we get cold enough airmasses to produce snow, or will it be a rainy winter, like last season?
We looked at previous Falls with a similar set-up, and we found that those winters often featured seasonable temperatures, with both arctic air and periods of thaw. What was common in almost every year was precipitation was above normal. That said, many of the years, the precipitation came as rain, not significant snow.
Also, worthy of noting, is that during La Nina years, lake effect events are less frequent than other seasons. That doesn't mean that the events we see won't be significant. Remember 2010-2011? That was a La Nina year with a lake effect event producing more than 30" of snow in one event!
In a nutshell, you can expect a winter season with periods of significant arctic air, like the past many years. However, we do expect periods of thawing as well.
It will most certainly be active, with multiple opportunities for rain, sleet and snow.