It’s that time of year again! Winter is just around the corner and that means wintry weather can start returning to our 7-day forecasts. How is our winter this year shaping up? Will we see a lot of snow and cold or barely a dusting and mild temperatures? We’ll start with a detailed look at our atmosphere before diving into winter folklores, and wrap up with our final 2021-2022 winter season forecast. Here we go!
Signs From Our Atmosphere
First, let’s discuss the famous El Niño and La Niña conditions. El Niño and La Niña are phases of the El Niño Southern Oscillation (ENSO). El Niño is considered the negative phase while La Niña is the positive phase of the oscillation.
The Climate Prediction Center (CPC) issued a La Niña Watch this past fall, meaning there is a likely chance La Niña conditions will be present through the upcoming winter. We had a La Niña winter last year, so we will be “double-dipping” so to speak this winter. What does this mean for the winter season? Typically, a La Niña winter favors a jet stream setup like the one below.
High pressure over the Gulf of Alaska forces the Polar Jet Stream (blue arrows) north and then dives south across the Rockie Mountains into the Central Plains before turning north again towards the Mid-Atlantic. Cold air remains north of the jet stream in the northern Plains with dry, warm air staying south. Northwest Arkansas and the River Valley are right along this boundary. If the jet stream moves farther south, the cold air could move into our region. The other side of this coin is if the jet stream stays north, we will see the warm air move into our area.
You can learn more about La Niña here:
If you are curious about La Niña’s cousin, here is what a typical El Niño winter looks like across the Lower 48 States.
Notice how there is now low pressure in the Gulf of Alaska. This causes the Polar Jet Stream (blue arrows) to remain well to the north in Canada. The true Arctic air stays locked away from the Lower 48 and leads to a warm, dry winter across the northern United States. In the South (including Northwest Arkansas and the River Valley), the Pacific Jet Stream (red arrows) flows from west to east persistently. Storm systems tend to ride along the track of a jet stream. With a more stormy weather pattern, the southern U.S. typically sees wet winters during El Niño years. The increased cloud cover from the wet weather will also keep temperatures a bit cooler than average.
Another type of atmospheric oscillation we need to look at is the Arctic Oscillation or A.O. When in its positive phase, the jet stream flows basically west to east and keeps the cold air north in Canada and the Arctic.
However, if the Arctic Oscillation enters a negative phase, the jet stream becomes wavier and the cold air trapped in the Arctic is allowed to sink south. This can lead to some of our severe cold outbreaks in the winter depending on if the jet stream moves south over the Central Plains.
If a negative Arctic Oscillation occurs with a disruption of the Polar Vortex in January or February, we could see a cold snap in the United States. The exact placement of the cold air will depend on where the dip in the jet stream occurs. Unfortunately, it is too far out for models to predict exactly where this will occur.
Winter Folklore Forecasts
Alright, now that we got through the scientific stuff, it’s time to look at some Winter Folklores. According to legend, persimmon seeds will tell you how bad the upcoming winter season will be based on the shape of the seeds. There are 3 possible designs you can get.
SNOW LOVERS REJOICE! It looks like the persimmons are predicting a harsh, snowy winter this year.
Hold on though! Persimmon seeds aren’t Mother Nature’s only clue on how Old Man Winter is feeling this year. Another folklore is “the number of fogs we have in August equals the number of snows in winter”. Okay, seems easy enough. It’s definitely a lot easier to count the number of fogs than cutting open persimmon seeds. So, how did we do this year?
We had 2 fog events reported at Drake Field in August 2021 with visibility 1/4 mile or less. That means two snow events this winter, right? Well, not exactly. The problem is Drake Field is in a protected valley and is prone to fog. To get an idea of the upcoming winter season, we need to look at widespread fogs.
Yikes, that’s not what snow lovers want to see! We had zero widespread fog events in August. According to legend, that means no snow events this year.
Another winter folklore includes “a hot 1st week in August = harsh winter”. The start of August 2021 was quite cool. 3.6°F below the average daily mean temperature of 78°F. That’s another point for #TeamNoSnow.
What about the woollies? Woolly worm caterpillars (aka, woolly worms) are said to give early warning signs about the upcoming winter season based on their color. A thinner brown line means a cold, snowy winter according to the legend.
Folks, we got a problem here.
It seems Mother Nature is being indecisive with the woolly worms this year. Guess it depends on which one you see on what kind of winter you will have at your house. Hopefully, you’ll get whichever woolly worm you prefer.
Winter Forecasts: Almanac Style
Okay, we looked at the atmospheric setup and winter folklore. Now, it’s time to go old school. The Farmers’ Almanac and Old Farmer’s Almanac! That’s right, we have two almanacs and that means two winter forecasts.
The “new” farmers’ almanac is predicting a “numb’s the word, just shoveling along” winter in Northwest Arkansas with a “chilled to the bone, near-normal precipitation” for the River Valley. Older means wiser right? The Old Farmer’s Almanac agrees a cold winter is ahead but it will also be snowy in Northwest Arkansas. Which one do you think will be more accurate?
NOAA’s Climate Prediction Center Forecast
The National Oceanic and Atmospheric Administration (NOAA) issues seasonal outlooks through the Climate Prediction Center (CPC). The Seasonal Outlook for Meteorological Winter (December – February) this year calls for a La Niña-like setup with a high chance of above-average temperatures across the south and the eastern United States. There is a slightly greater chance for below-average temperatures in the Pacific Northwest and northern Rockies.
The precipitation outlook is very similar to an expected La Niña pattern with increased chances of above-average precipitation in the Pacific Northwest, Northern Rockies, and Great Lakes with higher chances of drier than normal conditions in the south.
Northwest Arkansas and the River Valley are slightly favored for temperatures to be above-average overall this winter in this setup with precipitation in the neutral zone. This means our area has an equal chance of seeing above-average precipitation and below-average precipitation.
Your NWA Weather Authority Team’s Winter Prediction
Since the winter of 1987-1988, only 6 winter seasons have been below-average. Last year’s winter (2020-2021) was one of these years and there was a moderate La Niña present at the time. Everyone who was in Northwest Arkansas and the River Valley last year knows February was historically cold and snowy. We had two snowstorms within a week of each other and temperatures well below zero a few nights.
Here’s what we think will happen this year. First, the start of the season (December and early January) will be mild with colder weather moving in towards mid-January and February. While we are not calling for an outbreak of cold air like last February, we do expect a few cold snaps due to the negative phase of the Arctic Oscillation (A.O).
There will be periods of warmer weather embedded throughout the winter season, exact timing will be determined by the position of the jet stream. When everything is over though and Spring has arrived, we expect the overall winter season temperature to be below-average once again.
In terms of snowfall, we expect a couple of light snow events (enough to cover the roads and grass lightly) with one or two moderate snow events (enough to build a lifesize snowman or go sledding).
Given historical precedence of winter in Northwest Arkansas and the River Valley, we expect conditions to be present for a possible icing event at some point this winter. This is due to the fact pure all-snow events in our region are fairly rare (especially in the valleys). Overall, we expect the region to see near-average snowfall this year.
While we expect this to be the overall summary of Winter 2021-2022, the exact details and timing are still a long way from being worked out. Make sure to stay with your NWA Weather Authority team throughout the winter season for all the latest forecast information so you can stay ahead of the storm!