Good Wednesday morning to everyone across the Western Carolinas. A busy week continues for the weather team as we are monitoring what looks to be the first widespread winter storm of the 2018-19 Winter Season.
We have a classic split flow pattern, we have energy from the northern jet stream that will dive into the United States and will deliver a fresh, cold airmass to the Eastern part of the country including here in Western North Carolina. Meanwhile southern stream energy off the coast of California will move eastward through the second half of the week and by Friday will spawn a surface low along the Gulf Coast Region. These two players are going to combine forces to bring the Southeast US a strong winter storm capable of producing multiple precipitation types.
Computer model guidance continues to portray a very wintry scene across Western North Carolina starting on Saturday and last possibly as long as parts of Monday. There are still several factors that are up in the air at this time, here is a listing of things that we do and do not know as of this morning...
Forecasting winter weather in the Carolinas is never easy and each storm presents its own challenge. One of the big factors with this event is knowing that abundant moisture will accompany this storm. The models have shown that for days and continues to do so here at this point. The Weather Prediction Center is forecasting as much as two or more inches of liquid equivalent will be produced during this storm. And with temperatures that look to be sufficient enough for various frozen precipitation types, this is going to evolve into a high impact event for a good number of people...however not all threats will be uniform. Some locations have the potential for heavy snowfall while other spots could see more in the way of sleet or freezing rain.
While the confidence is becoming high of this being an impactful winter storm, the specifics still need to be ironed out which leads to lower confidence in that aspect. We feel its prudent at this point to share our early thoughts on the "potential impacts" from this storm.
The map below is general layout of where we think the highest risk areas are. We will be releasing a more detailed "first call" map for amounts at some point in the next 24 hours. At this time do not focus as much on the numbers as you should the entire story. Climatology usually favors locations along and north of Interstate 40 during this type of Miller-A winter storm...and right now we see nothing to think differently. Given the model guidance that has been provided along with personal forecasting experience, we believe at this time that our northern tier will see a major winter weather event that will impact normal daily function through the weekend and into next week. Right now the majority of those shaded in the grayish hue that you could see snowfall amounts approaching the low end of the range (with occasional) However we also feel that a few spots, most likely right along the immediate Blue Ridge could remain as mostly snow and with the model data showing high liquid amounts it could yield some impressive localized totals. The unusually long storm duration also will play a big role in amounts.
In the purple hue, we see a lot more complex and uncertain forecast at this time because we generally see a better chance of mixed precip types. That is going to help limit any possible snow or sleet accumulations. A degree or two difference at the surface or aloft could mean a wild variation of conditions.
Again, this is a fluid weather situation, changes in our forecast is quite possible over the next couple days as we get closer to the event. Regardless of what falls in your back yard, there is enough confidence in this being very impactful to the general public...here's a few extra bits of information to slide along as we conclude this update. Another High Impact Weather Outlook will be posted this evening...