It's that time of year again when I get the question "what type of winter are we going to have"?
All the the winter lovers out there are not going to be happy with this next statement, but here it goes:
This winter may very well be similar to last winter.
Why? The reason why is because just like last year, La Nina is playing a role in whether it is going to be a snow-less winter or a snowy winter. In fact, La Nina is playing a much bigger role in the winter outlook this year compared to last year because this year, La Nina is stronger.
La Nina is the cooling of the Equatorial Eastern and Central Pacific Ocean, which is the opposite of El Nino. La Nina changes the precipitation and temperature pattern. The usual precipitation pattern is wetter conditions in the Pacific North West and drier conditions across the southern tier states.
Although hurricane season was officially over November 30th, La Nina is one of the reasons we had a record-setting season. The cool water in the Pacific ocean commonly leads to weaker low level winds and less wind shear in the Caribbean. Hence, 30 named storms this Atlantic hurricane season!
La Nina was the main factor in why NOAA's Winter Outlook for the 2020-2021 season is calling for the usual pattern.....cooler and wet North and warmer and dry South.
La Nina, right now ,is the primary factor and main influence in why we could have a snow-less winter but not the only factor. We still need to look at the North Atlantic Oscillation/NAO, Siberian snow cover and the Polar Vortex.
I used the words "right now "because the NAO and the Polar Vortex are difficult to forecast far in advance. A negative NAO is good if you want a snowy winter because it brings the cold air north from Canada, south. The problem occurs if we don't get the cold air.
Siberian snow cover can also make for a snowier winter if there is a lot of snow on the ground in Siberia in the couple of months leading up to December.
More of you became familiar with the polar vortex a few years ago and it is a major part of winter forecasting. The polar vortex is cold air and low pressure at the poles. A weak polar vortex will lead us to reaping the rewards of arctic air gushing down into the United States but a strong polar vortex will keep the arctic air locked away and if that is the case, this winter season will likely mimic the 2019-2020, 2011-2012 and the 1949-1950 winter seasons....snow-LESS!
Taking everything into consideration, this winter season I am predicting above normal temperatures and near normal precipitation. The average snowfall in Baltimore is 20.1"
I'm forecasting 2 big snows, 6 inches or higher. There will be several systems that move in December through February but much of the precipitation will fall as a wintry mix, which will cut down on the snow totals.
With that said, snow lovers, it only takes 2 big snows and several little snows to have a fulfilling snow season!