By: Chris Fischer
The Winter Solstice occurred Dec. 21st (at 9:27 p.m. CDT, to be precise). So, Winter must have finally arrived.
“The Solstice draws Winter astronomically.” Megan Mulford, a meteorologist with the National Weather Service’s Aberdeen office clarified.
Mulford explained that for them, winter started Dec. 1st. To meteorologists, Winter in the Northern Hemisphere takes place during the months of December, January, and February.
After the solstice, the Northern Hemisphere gets cooler temperatures and longer nights.
The Winter Solstice is known as the shortest day/the longest night in the Northern Hemisphere. The Solstice awarded us a paltry 7-ish hours of daylight. We had basically turned our backs to the Sun.
The Earth isn’t a circle that’s straight up and down. It’s a bit askew, crooked in relation to the Sun. That’s why one hemisphere is always a bit closer to the Sun than the other one is. On the Winter Solstice, we were the furthest from the Sun all year.
In the Southern Hemisphere, the longest day and shortest night – the opposite of the N.H. was marked. In between the hemispheres, in the equatorial region, “The Sun’s rays are directly on the Tropic of Capricorn.” said Mulford.
The equatorial region isn’t much affected by the solstices.
The Tropic of Capricorn is 23.5 latitudinal degrees south of the equator. It’s not a real line – more of a line of reference on a map.
The Tropic of Cancer is equidistant from the equator. It receives the sun’s direct rays on the Summer Solstice in July.
To think of half of the world starting Summertime right now…
Speaking of the Sun, can we expect more unseasonably warm weather?

According to Mulford, things should continue to be warmer and drier-than-average. This is due to a stronger El Nino. (More on that in a minute.)
Temperatures throughout Northeastern South Dakota were warmer than average for Nov. and Dec. Snowfall was below average.
She explained that last year, from Oct. 1st to Dec. 15th, Aberdeen had received 15.6” of snow. This year, the same date range yielded 1.5 inches. In Pierre, the same range last year saw 16.2”. This year there was 3.5”.
Mulford warned that we could still see a lot of snow in Feb.-Mar. and into April. But in “past El Nino years,” the snowfall stayed “below average.”
Mulford predicted that temperatures in NE SD would be 60-70% higher than average for the next several days.
“In Aberdeen, the end-of-Dec. average high is 24. (The record high was 54.) Forecasted temperatures are in the mid-to-upper 30s.” she said.
She noted that the 27th of Dec. was forecasted to have a high of 35, which was 10 degrees above average.
January should also see temperatures that are 60-70% warmer than average.
But it’s not always easy to know what’s coming. Mulford explained that they can predict weather 0-24 hours ahead with 80-100% confidence. At around Day 3, confidence is around 50-80%. Longer than that, say at Day 5, confidence falls to about 30%.
“It’s like trying to predict a hurricane.” she said. “You know it’s coming but not where it’ll hit. You are forecasting as the weather is progressing.”
One bit of good news – a holiday blizzard is pretty unlikely. There could be a bit of rain or rain/snow mix. But Mulford predicted “little travel impaction.”
There could be some winds picking up, however.
Meteorology entails looking at a lot of computer models. Mulford explained that nowadays, there are ‘ensembles,’ which are like models-within-models. Meteorologists “look within” the models to determine probability.
Each weather service takes readings of daily highs and lows, as well as other data. Climatologists look at records from 2000-2020. The highs and lows are averaged. Weather data is compared to overall means to see if it’s not following patterns.
It is unclear whether climate change causes stronger El Nino.  
According to www.climate.gov/enso (accessed 12/21/23), El Nino is the “warming phase” of a “pattern” of weather in the Pacific Ocean. La Nina is the “cooling phase.”
Together, El Nino and La Nina are El Nino-Southern Oscillation.
We are affected, according to Mulford, because they are circulated back to the Midwest through jetstreams.
She said that things have to do with sea temperatures in South America, the strength of the polar jet stream, and subtropical jets.
“La Nina results from cooler ocean temps off the coast of South America. This results in weather that is cooler and snowier.”
“El Nino involves warmer average ocean temps off the West coast of South America. It results in warmer, drier weather.” she said.
 We may as well make the most of our milder weather.