Tony Lupo, a professor of atmospheric science in the University of Missouri College of Agriculture, Food and Natural Resources (CAFNR), said this past fall – the months of September, October and November – was the sixth warmest in Missouri since the state began keeping records in 1889.
Halfway through December, mid-Missouri is seeing temperatures that are averaging 10 degrees above normal. Lupo said two factors have led to a rise in early winter temperatures – and a potential for a warmer winter overall.
“We’re experiencing back-to-back La Niña years, which, historically, when that happens, the second La Niña year is warmer than the first,” Lupo said. “To go along with that, the drought out west continues to play a massive role in our higher temperatures. The drought is leading to sunnier days and high temperatures that have been above normal.
“Both of these situations are combining to make temperatures awfully warm.”
Lupo said those factors also played a role in the recent severe weather and tornado outbreak that hit the Midwest.
“There is some cold air up north but it’s just not been able to penetrate this ridging caused by the drought,” Lupo said. “However, some cold air did manage to penetrate and it set up a huge contrast – and it made everything explode. This is the type of storm we see in the spring, not in December. We’ve had tornadoes in December, but not usually of this magnitude.”
Lupo released his winter weather forecast in August. His original winter forecast had temperatures 1 to 2 degrees higher than normal, with normal levels of precipitation and around 15 to 20 inches of snow, which is within normal range for mid-Missouri.
Lupo said with how things currently stand, he might have a few small tweaks.
“So far, some of those drought conditions are creeping toward us,” Lupo said. “Hopefully the pattern changes and we get some rain soon, as small amounts of precipitation now can really impact us in the summer months. As far as snowfall, I think I may revise that downward, to 10 to 15 inches. If the pattern doesn’t change soon, I don’t know that we’ll see much snow.”
Lupo said that if December ends how it has begun, the average temperature throughout the year would be 2 degrees above normal for mid-Missouri. Lupo added that would be a fairly substantial and unusual change.
“It honestly could have been warmer, too, without the polar vortex we experienced in February,” Lupo said. “That made for a ridiculously cold February, and if it wasn’t there, the year would have been 1 degree warmer. Essentially those two weeks cut off an entire degree from the year average.”
Lupo said there is a chance that temperatures return to seasonal averages between Christmas and New Year’s Day.
“We’ll eventually see some cold weather,” Lupo said. “But unless things change soon, it’s not going to be much of a winter.”
Even if temperatures stay warm, Lupo said you should continue to stay ready for potential winter weather events.
“Things can always change quickly,” he said. “You should definitely make your regular winter preparations. Even in a warm year, you can have a 6-inch snowfall that causes issues. Make sure that your cold-weather remedies are ready to go.”