Winter Weather Possible This Weekend? Yes. How Much, Where, And Exactly What?
We are watching a pattern that has developed in the model data over the last couple of days. This new pattern would be one that returns our temperatures back down to seasonal averages and briefly turns quieter.
That quiet weather won't last though. The winter is certainly looking interesting over the next month and you don't have to look further out than this upcoming weekend. A storm system looks like it will slide across the Southeast United States bringing unsettled weather back into the area just in time for the weekend. There is great uncertainty though as to the specifics. Those questions range from the amount of cold air that will be supplied into the region and the amount of moisture available for this storm. Both are key along with the eventual track.
Version 1 of this High Impact Weather Outlook has a lot of graphics to show what we are discussing here. First off though the setup. Models inject a lot of water vapor into the Southern Jet on Thursday and it looks like low pressure could develop somewhere between Northern New Mexico and Northwestern Mexico (yes the country) sometime between Thursday Night and Friday Morning, depending on which model you want to take your trust in. A pretty wide gap in the unknown already by this point in the forecast. So lets blend the two models. Taking the middle of that road between the Euro and GFS that would produce a very weak low pressure system over Western Texas by predawn Friday. From here the two models really start separating. The GFS develops a weak low over the Midwest United States and that low taps into Gulf of Mexico moisture ahead of the organizing low pressure over Texas. The Euro doesn't have this feature. So for now lets just say a weak low does develop over the plains but limit it's moisture intake. So our forecast so far produces a weak low pressure system over Lubbock Texas predawn Friday. By Friday Afternoon a additional weak surface low develops, lets call it over Kansas, and moves it East. By Saturday Morning our low pressure tracks to somewhere between Dallas Texas and the Southeast Texas Coast. Coming into closer proximity right? So taking the middle of the road our forecast takes the low pressure to about midway up the Louisiana/Texas Boarder, just East of Lufkin TX and just South of Shreveport LA. Now by Saturday Morning a weak piece of energy appears in the Northern jet on the Euro, the same piece the GFS had earlier in the forecast cycle over the Midwest. By Saturday Morning the GFS is developing a nice plume of moisture out ahead of the Northern stream energy that is surging North out of the Gulf of Mexico. By Saturday Afternoon the closed southern stream system low pressure is even gone on the Euro. So those are just a few aspects of why this forecast is too soon to call for sure yet. Oh wait though, the supply of cold air? It becomes present in both the Euro and GFS with high pressure over the Great Lakes....or over Canada depending on your model of choice. So at this point here is our forecast that we are going to blend experience and model data together.
Friday will be dry around Western North Carolina while our eyes turn out to the West. A front should stall somewhere close by on Friday and then hang around for a while. Meanwhile high pressure builds to the North and by Saturday is funneling cold air south, just how far south we don't know. It all depends on how strong the high pressure is to the North, where that front stalls, and the track of the low pressure.
Friday Night we think clouds will be increasing and becoming overcast by Saturday Morning. Right now we will keep the area dry and hold the moisture plume to the West, only getting to about Nashville by Noon Saturday. Cloudy skies and an insitu CAD (Cold Air Damming) event gets underway as high pressure continues to supply cold air into the region. Saturday Afternoon precipitation could be arriving into the Western Carolina's and by this point all of Western North Carolina could be seeing light snow.
Saturday Evening snow continues to fall as low pressure tracks just inland along the Gulf Coast with moisture return picking up across the area. At the same time the first wave of precipitation is moving out to the Northeast. Right now I don't think there will be much of a gap in between precipitation shields. Saturday Night moisture surges North ahead of the low pressure along the Gulf Coast that could be weakening. Energy would be transferred to the Southeast Coast where cyclogenesis takes place and continues to funnel precipitation into the area. A burst of heavier precipitation could be seen around daybreak Sunday. From here our forecast would take the low pressure Northeast, not running directly North up the coast, and by Sunday Afternoon precipitation could come to an end. Before it does so a warm nose of air aloft could build into atleast parts of the foothills transitioning the snow over to freezing rain for Sunday. Right now though there is just no way to tell but experience always tells us that the high pressure to the North is usually under forecast and the CAD events hang on a bit longer than models indicate.
There is no way to know exactly how much snow, if any, falls over the area because there are so many variables and moving parts to the forecast. We will obviously keep you posted. I hope that the first paragraph just illustrates how hard it is to predict a system out 5-7 days when you are talking about precipitation types. Any change in the track of just 30-60 miles would change the precipitation rates, timing, and types. Stay with us though as we keep you posted, here at Foothills Weather Network. If you want a snow map right now you may have to search social media for the hypecasts because there is no where near the confidence to produce one at this time. We will however show you the three potential tracks that we are seeing and what would occur with each. Here are the graphics for Version 1 of the High Impact Weather Briefing.