Friday, December 8, 2023

Winter Forecast 2023-24

This winter forecast might seem late because we already had a nice snow event right after Thanksgiving. Considering we are just a week in on meteorological winter and the solstice isn't until the 21st, we still have the entire season ahead of us. You've probably seen a few winter forecasts out there floating around, probably on the social platforms, but I think it's important you hear from us what our thoughts are going into the season. 

Overall:

I don't think this winter is going to be that cold at all. I'm fairly certain we will make it through December with no Arctic air at all. It's amazing. Even as we write this up, looking up into central Canada of all places, nighttime temperatures are in the teens. That's not Arctic air and it will be several more weeks before we even see a chance of it coming this way. 

I do believe the heart of the cold is focused over January this winter. You might be saying "isn't it always that way?" Just remember two years ago in February of 2021, we had two full weeks of sub-freezing weather. It went all the way to the Deep South and is something we still talk about today. And there are years where the worst of the cold comes in December, and then it's a cake walk in January and February. Whatever Arctic air we get this winter should be fairly brief episodes, but again, January looks cold. February looks a bit milder (or "less cold").


What's the biggest driver of the winter forecast?

It's El Niño and I'm guessing most of you have heard it referenced before. Last year at this time, it was La Niña, and the two can be confusing. El Niño is warmer than average water along the Equator in the Pacific and La Niña is the opposite. In an unusual scenario, we had 3 back-to-back years of La Niña which are notorious for summer droughts and prolonged heat waves. Now that El Niño is here, odds tend to be in our favor of getting more moisture. The map below shows what a typical El Niño winter does for precipitation in Kansas, but this is an average and not necessarily what this winter will do. 

This El Niño is a strong one, as the water temperatures (in the green box) are running about 2°C above average. It's not historic, but at that level, there should be a pretty solid influence on the jet stream well into spring (and maybe beyond). The last El Niño of this magnitude (or stronger) was back in 2015-16.

One other considering factor is the Pacific Decadal Oscillation (PDO) which also deals with warm and cool water in the Pacific (hence the name). Cool water along the North American coastline and warmer water in the North Pacific is a "negative" PDO - that happens to be the phase we are currently in. In the graph below, you'll see how it bounces back and forth, and this year a negative PDO and an El Niño are happening together. We don't have much history on the two happening together, but in the few cases that we do have, winter snowfall was higher than average. 



Other takeaways:

A very active southern branch of the jet stream seems inevitable, and it already appears underway. Kansas is likely going to be on the northern fringe of it, so look for the better moisture (and more significant drought removal) to be in the southern half of the state this winter. This is also where the better snowfall will probably be this winter.

There is another piece of the winter pattern that will bring some milder/warmer stretches of weather. When Alaska is getting snow and much colder weather, we will likely have a warmer setup in the Plains and the northern Plains. 

Just for fun:
I compiled past El Niño winters (including the weak ones) and what the snowfall amounts were for Wichita, Goodland, and Dodge City. See for yourself - the amounts are highly variable. 

Wichita:

Goodland:

Dodge City:


What do the seasonal model forecasts have:
The warmth of December and nighttime lows will likely contribute most to the warmth that you see in the map below. Arctic air will find its way to Kansas, but as mentioned above, they will probably be short lived. 

Precipitation:

More classic El Nino signatures here with above average moisture forecast for the central Plains. I would be a little suspicious of northern Kansas being "above", but there's reason to be hopeful this winter provides enough moisture to keep the drought from rapid expansion (and in some cases, it should even improve).

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