(WVNS) — Not too long ago, NOAA released their 2022/23 Winter Outlook for the nation detailing observations, likely outcomes, and historic comparisons of years past. Talks of La Nina, jet stream fluctuations, the dreaded polar vortex, and other topics helped NOAA meteorologists reach a consensus on what they think the U.S. can expect.
Of course, we here in the two-Virginias want a more local view of what to expect this year and luckily for us, we have the StormTracker59 team diving into the research, discussing, and then fine tuning the work NOAA meteorologists put in to give us that local look at what our winter may look like.
Pacific Ocean Temps and La Nina:
La Nina is simply when warm ocean waters along the equator in the Pacific Ocean migrate west towards Australia. Strong westerly winds and weaker ocean currents in the area allow warm water to move out while pulling up colder waters off the South America coast lines. In an El Nino year, the opposite is true with warmer water closer to South America. When there is no La Nina or El Nino conditions present, it is referred to as neutral. For December and January, there is 75% of La Nina conditions continuing and a 54% chance of neutral conditions February onward according to NOAA Climate Predication Center. But what does this have to do with us in the two-Virginias? Quite a bit as it turns out.
As complex a system as our planet is, everything is connected. Changes in wind or ocean temps in the Pacific change how our weather is formed in the U.S., where it comes from, and even severity. Much of the reason meteorologists pay so close attention to La Nina and El Nino from one season to the next is in an effort to see how it will change our jet stream in North America.
Jet Stream Changes:
Our jet stream is very strong, very persistent winds high up in our atmosphere – roughly 30,000 feet or so moving about 100-200mph. It fluctuates in height too, depending on the season, something frequent air travelers know as cruising altitudes of cross country flights change season to season. Regardless, our jet steam is responsible for where weather systems form, how they move, and even our temperatures from day to day. Moving up or down in altitude, changes in speed, or location over the county all play a part in our weather from day to day.
When our jet stream moves north, also known as a ridge, warmer air can move up north as well. When the jet stream dips, or a trough forms, colder air dives south. For a La Nina year, typically our jet stream takes a more northern track in the eastern U.S. – good news for folks who like a more mild winter. With this setup we typically have more days through the winter months above average.
While it looks as though we’ll still have more days above average than not this winter, let’s consider what our averages are. In Beckley, climate averages from 1991-2020 have November at 53 degrees, December at 44, January at 40, February at 44, and March coming in at 52 degrees. With more days than not above average, most storms that come through our region look to be on the rain side of things if past years are any indication. However, fluctuations in our jet stream are normal, and we have to consider the Polar Vortex in the mix as well before calling for a snow-free winter.
Precipitation Changes with La Nina:
Our Jet Stream is also responsible for weather systems in the northern hemisphere. Changes in wind direction form upper level low or high pressure systems, creating areas of rain and snow or sunshine and blue skies. It also dictates where systems can move, steering them from one place to another. With a typical La Nina setup our jet stream moves south from the Pacific Northwest, across the plains, than up along the East Coast. Keeping us in line to see a few rounds of storms push through the winter months keeping us above average in precipitation totals.
Typically for Beckley, winter is rather dry compared to other seasons of the year. The biggest change, of course, is how the precipitation impacts us. Cold temps and snow seem to cause more disruptions than rain showers in summer. However, with La Nina conditions expected to kickoff the winter season and therefore warmer than average temps likely, rain totals are looking to take an uptick for most of our region. Not to say we won’t see wet flakes, sleet or the likes, but historically, La Nina means a wetter pattern not a snowy one. However, places like Snowshoe or the higher elevations farther north, La Nina or not, snowy winters are almost always expected thanks to a unique setup with northwest winds bringing in moisture from the Great Lakes.
So far, indications for our winter outlook tend to be slightly warmer for December and January with a little more rain than normal. But, we’ve all heard the hype around the Polar Vortex. Let’s take a little of the bite out of the phrase. The Polar Vortex is simply air in the upper atmosphere, much like our jet stream. It typically encompasses the North Pole and moves up and down like our jet stream. Factors like persistent high pressure in the Northern Atlantic and Russia push and pull on both our jet stream and polar vortex. If these factors push or pull hard enough, they can bring the Polar Vortex farther south bringing arctic air into the lower 48. Think back to February of 2012 when we saw two weeks of temps in the teens. This was a result of the Polar Vortex diving far south and with it polar air.
La Nina will help us keep the polar air towards the North Pole to start our winter season but as it weakens, so does its influence on our jet stream. This opens us to the risk of seeing arctic air towards the end of January into February leading to very cold days and a few chances of decent snows.
Now that we have some of the factors that go into winter weather forecasting for our region, here’s our StormTracker59 team’s thoughts on what our winter may look like. For much of our region, temps should fall in line with a more mild tone for December and January. A few chilly days are certainly possible but when viewed as a whole, we’ll see more mild days than not. Storm systems that do move in will be more southerly systems moving in from the Tennessee Valley than not. With this set up we typically see a surge of warm air before cooler air pushes in behind. This is a good set up for more rain than snow but a few strong storms could still bring in enough cold air to end as snow or even sleet and ice. And with La Nina, we’ll see more of these systems thanks to the position of our jet stream, giving us a rather wet December and January.
Moving farther into January and February, a weakening La Nina means temps could slide below average for much of the time. Wobbles in our jet stream as a result make it a bit more difficult for storm tracks but historically, when La Nina fades during the winter months we see a gradual change to these cooler temps and drier conditions. With this, January and February could see some decent snows as a southerly track in storms is favorable for snow in our region.
It’ll just be a matter of those storms sliding to the west of us through Kentucky which brings us rain.
Or to the east along the VA coastline which sets us up for a good snow. The wobble in our jet steam will be the determining factor but the possibility is there.
Of course, this is a broad overview using historic averages and trends and with the unique topography we find across our two states, each day will be different. As mentioned before, the mountains typically see more snow than the lowlands like Beckley do thanks to northwest winds dumping moisture from the Great Lakes on them. For these areas, there isn’t much of a change in that aspect of winter but La Nina should keep big snowstorms away, at least to start the winter season. Overall, as accurate as long range, climatic forecasts can be, betting on a mild and wetter winter to start is the safest bet, keeping in mind Mother Nature has a way of doing what she wants day to day.
No matter what winter weather set up we find ourselves in from one day to the next, know your StormTracker59 team will be there every step of the way, diving into the models, pinpointing tracks, and providing you with the most accurate forecast possible. Even when Mother Nature decides she’s not following historic trends.