ROANOKE, Va. – Last week, we told you about NOAA’s first stab at the forecast for the upcoming winter. While NOAA’s outlook relies heavily on the El Niño Southern Oscillation, our approach takes a few other things into account.
Yes, the El Niño typically favors a more active storm track in the Eastern U.S. However, that doesn’t tell the whole story.
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*We’ll need to monitor snow cover in Siberia and tropical activity in the Atlantic during the month of October. Keep reading to learn why.*
In order to get snow, you need active storms, but you need a wealth of cold air. That’s especially the case around here, where layers of warm air above the surface can change us to sleet and freezing rain.
Cold Air
When making a winter forecast, we look at two key things to determine the frequency of cold air outbreaks. One theory suggests that solar activity can influence that.
Another theory suggests that snow cover in Siberia can affect how much cold air is available to seep into the Eastern U.S.
This is a key feature that we’ll need to watch in the month of October to see how much snow cover will expand up there.
Storm Track
We already established that an El Niño phase typically leads to more frequent storms. However, there is another thing we’re watching that plays a big role on how many storms we see in the winter.
Believe it or not, the amount of activity in the tropics during the summer and fall can be a harbinger of what to expect in the winter.
Tropical systems send energy toward the poles. The more energy transferred, the less that’s needed to be transferred in the winter. And vice versa.
Tropical systems can and do still form in October, which is why we need to monitor that activity this month before making an official winter forecast.
Our team is actively working on putting the winter forecast together. Expect that to be released in early-to-mid November on air and on wsls.com.
