Winter Weather Outlook (1/14, 3 pm) for Sunday Jan 18

Good Wednesday afternoon,

Our weather team continues to monitor the weather pattern for later this week as cold air is going to be firmly entrenched with pieces of upper-level energy moving through this weekend.

If you look at the water vapor image, you can clearly see an area of high pressure aloft along the West Coast of the US. This is known as a +PNA teleconnection and history states that a +PNA supports cold and increased winter weather opportunities in the Eastern and Southeast US.

One piece of energy is currently located off the West Coast of British Columbia (Canada) and will drop into the United States by this weekend.

The big question right now is “where” and “just how strong” will this feature be come late Saturday and into Sunday?

At least one piece of computer model guidance has made a trend in the past 24 hours of that energy crossing directly over the Tennessee Valley and Southern Appalachians on Sunday to now diving along the Mississippi River to the Mid-South Region. That west trend supports of the idea of a developing area of low pressure somewhere along the Gulf Coast or just off the Southeast US coast.

Now that we are seeing this trend on the deterministic model runs, we are starting to dig deeper into the ensembles and what they are showing and how they are lining up in comparison to the deterministic.

Ensemble forecasting helps produce a better look at what is most likely compared to high-end scenarios that are common within deterministic model runs 3-5 days out.

GFS Ensembles

Today’s GFS Ensemble suite has definitely increased the odds of “snow falling” during the day Sunday across the state of North Carolina outside of the mountains.

We will use ensemble data for Hickory as it is the most centralized location in our coverage area…

22-of-30 ensemble members: Trace or more

6-of-22 ensemble members : 2+ inches

8-of-30 ensemble members: zero snow

Ensemble Mean (Average) : 1 inch

European Ensembles

20-of-50 ensemble members: Trace or more

1-of-20 ensemble members: 2+ inches

30-of-50 ensemble members: No snow

Ensemble Mean (Average): 0.3 inches

Summary

There has been a slow but notable trend today in the “potential” for some snowflakes to accompany the cold blast which is predicted to move in this weekend. There are no signs of this being a significant event currently but the signal for snow looks better than it did 24-48 hours ago.

We will officially break out the Winter Storm Index and place it at Level 1 “Social Media Talk”. Stay Tuned!