Winter is starting to show up - get ready

We've been enjoying some very mild weather for December, but it would appear this is about to change in the coming weeks. We still haven't had any Arctic air and this month is on pace to be a top 10 warmest around the state. Look at these stats as we hit the halfway point in December:

• Goodland - 4th warmest
• Salina - 7th warmest
• Dodge City - 8th
• Wichita - 9th

Nearly the entire country is experiencing a very warm month so far, and I don't look for that to change much between now and year's end. It's been pretty strange. 

Couple of things to watch:

Arctic oscillation: This can sometimes be the first clue of a major shift toward warm or colder trends. We've covered this before, but a "positive" Arctic oscillation indicates less cold reaching us from the polar region, while "negative" AO values suggest a better chance of an Arctic invasion. 

What are we seeing now? It's been pretty positive lately, but a trend to negative shows up into the early days of 2024. Will it be an abrupt shift or a gradual easing? My suspicion is that we will ease into the colder weather, and even if we do see some Arctic air coming in, they may be brief bouts of it. 

Building high pressure in western Canada:

If we see high pressure (or a ridge) going up in western Canada into early January, that could easily signal an invasion of bitterly cold air coming into the lower 48. This setup has not been a reality yet in December, but a shift to this may happen in the coming weeks. 

All of this leading to a forecast map that looks like this for early January:

And here's another preview of mid-late January:

Of course, the southern branch of the jet stream (also known as the sub-tropical jet) will remain active too, bringing more moisture off the Pacific and right into the desert Southwest and across the southern Plains. This is classic of El Nino setups, but will the bitter cold from the north meet up with the moisture coming across the south? 

Heads up for a post-Christmas storm:

While we won't have a white Christmas this year, just beyond the holiday we will have another low pressure tracking across the Southwest and into the central/southern Plains. If you are going to be traveling around the holiday, consider this early heads up to some active weather. I don't think it will be a big winter storm (given the lack of widespread cold), but we have to watch and wait. The model image below highlights the wet weather from California to Plains and deep South. Those green colors represent above average moisture (in much of Kansas, this is .50-1" ABOVE), so could easily be a pretty wet system coming on through. 

Have a great day and thanks for spending a few minutes here.