Last winter was an eventful one here in the Two Virginias and if we look at it as a whole from December 1st to the end of February, we saw a colder, wetter and snowier than average winter.
Breaking it down into months…
December was the milder month with average temperatures above normal. It was also the wettest December on record for Bluefield. We saw relatively wimpy snowfall amounts for the area, but had an ice event mid month to deal with.
January was the cold month, with average temperatures well below normal and a few record breaking low temperatures recorded. We saw several mornings through out the month of temperatures below 0. Precip was below average but snowfall was slightly above.
February brought the snow, with higher than average snowfall for both Beckley & Bluefield. We had a few good storms that month and one in particular over February 12-13th.
We weren't alone either, much of the central and eastern US saw a cold and snowy winter.
As we look at this upcoming winter, there are many factors to consider…
First, let me do my yearly reminder that accurately predicting a season is no small task. Most winter forecasts you see will be fairly general as well (like colder or milder than normal, snowier than normal), instead of narrowing down exactly when snow storms will hit and how much snow you will see.
Without getting too technical, there are many different variables to consider when forecasting for an entire season, for example:
~El Nino-which is being forecasted to develop, but hasn't yet. With a weak to moderate El Nino, our forecasts tend to be cooler, but slightly drier than normal.
~Snow in Siberia-I know it sounds strange, but there is a good correlation between a heavy snow season in the Autumn across Eurasia and better blocking-leading to a colder Eastern US. The heavier snowfall effects the polar vortex by warming and weakening it… allowing the arctic to be warmer and the colder air moves southward into the US.
~Solar activity-there is a correlation of low sunspot activity and a lot of blocking (due to strong negative NAO and AO)
~NAO (North Atlantic Oscillation) shows fluctuations between the Icelandic low and the Azores High. When this is negative, we tend to see colder, drier air masses-but storms are still possible.
~AO (Arctic oscillation) – state of the atmospheric circulation over the arctic. In the negative phase, the polar low pressure system (also known as the polar vortex) over the Arctic is weaker, which results in weaker upper level winds (the westerlies). The result of he result of the weaker westerlies is that cold, Arctic air is able to push farther south into the U.S., while the storm track also remains farther south.
~SST (Sea surface temperatures) –around Alaska, Pacific NW- if warmer (like last year) then a ridge forms, allowing for a trough of low pressure in the eastern US=colder.
So, with these (and several climate forecast models we look at) there is a lot to consider.
From what I've seen in the recent data, there is hinting at a negative phase of the NAO and AO continuing. SSTs in Alaska are warmer than normal and snowfall in Siberia was at record levels in October (though it scaled back in early November). Solar activity is relatively low, but there have been recent fluctuations. A weak El Nino is possible, mainly later in the winter months.
With all of these factors, I'm leaning to a cooler than normal winter. We have the potential to see more cold air outbreaks, but it's possible they won't be as dramatic or long-lasting as last year. January into early February would be the most likely time for our coldest air (but it usually is).
In terms of precipitation, that's tricky. NOAA has us under equal chances to stay normal or go above or below it. Some of the climate forecast data hints at the main storm track this winter being very close to us, which would bring several chances for wet weather & give us a wetter than normal winter. Plus, if the cold air is available, some bigger snow storms are possible too.
This winter may look a lot like last winter, but with better snow chances in December and January, then a colder and drier February-especially if El Nino does develop-then the more active storm path would be closer to the coast.
There are a lot of different forecasts out there, so take them with a grain of salt. Many are similar to mine and leaning toward another cold winter here in Appalachia, so be prepared. Like most of our winters here in the mountains, cold outbreaks and snow storms are likely and may linger several days or weeks.
Through the remainder of this week, the precision weather team will have tips on how to prepare and stay safe this upcoming winter season!