Good Monday, folks. The first full week of December is kicking off with much colder air pressing in from the northwest. This air grows colder as over the next few days as periods of light snow and flurries settle in. All of this is ahead of a southern stream storm system that may impact our weather late Friday into the weekend.

As mentioned, colder air is pushing in today with highs generally in the upper 30s and low 40s. A shower or two will be noted and should be mainly rain, but a few flakes will be possible during the evening…

Periods of light snow, snow showers and flurries  then work across the region over the next few days. Light accumulations are a good bet, especially Tuesday night and Wednesday. That’s when we have a chance at delays and cancellations.

Can a few areas pick up an inch or so total from the next 2 days? Yep and the models are getting closer. The Hi Res NAM only goes through Tuesday night…

The new version of the GFS

GFS

Another weak system brings some rain and snow our way late Thursday into Thursday night. That’s a fast mover and looks fairly light.

That brings us to our developing winter storm and the potential impact on Kentucky. Like with any storm… It’s all about the track of the low, but we are still a few days away from being able to say with confidence where that will be.

The latest Canadian is a big hit across the bluegrass state…

The new version of the GFS has a similar hit…

The GFS impacts the southern half of the state…

The bias of the GFS is for such systems to be too flat and too far south and east. Of course, that doesn’t mean it will correct north and west, but I’m pointing out the well documented bias of the model.

The European Model went from being the farthest north of the models, to being the farthest south on Sunday. The latest run adjusts to the north and west, but it still has some very obvious issues. Convective feedback has been a problem with the Euro all year and it’s showing up in the initial stages of our storm developing across Texas. Convective feedback is when a model develops spurious thunderstorm clusters that show up as bullseyes of heavy rainfall. You can see those diamond shape issues on the first three panels I’ve highlighted…

The model gets confused by the false convection and jumps the low near or under where that spurious thunderstorm action is. It also typically slows the overall progression of the system on that particular model. Look at the fourth panel above and you will see the model is losing the feedback issue. Now, watch how quickly the Euro then tries to correct itself north and west…

Even with the convective feedback issues, it still manages to bring hefty snows into areas of central and eastern Kentucky.

There is still a lot of model shaking out to do in the coming days. You’re still gonna see some wild swings until about Wednesday. That’s when things should settle down, with this storm much more in focus for the models.

That said, I’m probably going to put out an “outlook” map later today, so check back. Make it a great Monday and take care.