Weather Blog

Potential Winter Storm December 28-30th?

I've noticed there's a lot of talk around town about a potential winter storm threat around the New Year, plus I have gotten a couple questions about it from viewers on Delmarva, so I thought I'd address it here in my blog. The short answer is yes we're watching the time period between December 28-30 for a potential winter storm.

For a while now, the computer models have been advertising a fairly strong arctic air mass moving into the northern Plains over Christmas weekend and heading southeast towards Delmarva just after Christmas. Models continue to show this happening, and now they're jumping on the possibility of Delmarva seeing a mixed bag of precipitation as we get closer to the New Year, mainly in that 28-30 time range.

If you want snow, the first thing you need is cold air and models are showing that. The second thing you need is a storm or organized area of precipitation to move in. There are a few other factors we look at that help increase your odds of seeing a winter storm, and they aren't all perfect, but they don't need to be all the time. I does look like there will be some type of storm developing along the southern edge of arctic air that will already be in place late next week. So the ingredients aren't perfect, but they may be starting to come together. Of course it is way too early to determine precip type and amounts, but potential exists for a messy end of December, and a possible white one. As you all know, a storm 7-9 days out is tough to forecast or even just speculate about because the weather changes so often, but this is a busy time of year and a lot of people will be traveling, so I think an early heads up is a good idea. Plus, I do have higher than normal confidence in this storm occurring due to the latest pattern and other factors that help us forecast the longer range, including ensemble data.

For example, we always talk about models right? Every operational model (GFS, EURO, CANADIAN, etc) has ensemble models that go along with it, usually around 50 or so. Just think of the ensembles as your twin brothers and sisters if you were to be a twin. All of your DNA is the same and you all think somewhat similarly, but you all have slightly different ideas and opinions. After all, you are all unique individuals, just like each ensemble model is unique. Meteorologists have programed these ensembles and we use them mainly in the long range to help us determine whether or not the main operational model is on to something or just making it up. In this case, the ensembles seem to agree that the cold air will be around and that a storm will develop at the end of December. Will it be rain, snow, freezing rain? What about its exact location? Stay tuned, we'll keep tracking this possibility as the details become clear as we get closer.

Below are some computer models and what they depict. Blue & purple is snow, pink is freezing rain (ice), and green & yellow is rain.





More Stories in the News