Significant Winter Storm To Likely Impact Parts of the Southeast Late Week

snowfall map

Synopsis

A potent shortwave will dive southeastward across the Rockies and enter the Southern Plains on Wednesday. The feature will develop into a closed low on Thursday over the Mid-South, triggering the development of a surface cyclone along the Gulf coast the same day. By early Friday, the system will reach the Georgia/South Carolina coast and trek up along the Southeast coast on Friday.

This system has a chance to bring a round of accumulating snowfall on Wednesday to far eastern Oklahoma and Kansas, northwestern Arkansas, southern/western Missouri and areas northward on Wednesday. A snowstorm will impact parts of the Southeast late Thursday into Friday, potentially including far northern Alabama and Georgia, eastern Tennessee, far southeastern Kentucky, far southern Virginia, Upstate South Carolina, and western/central North Carolina.

Forecast Discussion

As the low strengthens late Thursday into early Friday, a warm nose will attempt to works its way into southeastern Tennessee, northern Georgia, northern South Carolina, and western North Carolina. However, the passage of the strong mid-level closed will offset the magnitude of warming that otherwise would have occurred in the low levels. Strong frontogenesis across northern Georgia, upstate South Carolina, and central North Carolina could provide the necessary forcing to bring the freezing/melting level close to the surface in those areas. Evaporational cooling will also initially lower temperatures at and just above the surface. Despite lackluster cold in place across lower elevation regions in Georgia, the Carolinas, and even Southeast Tennessee, the dynamics of this storm system may actually ‘make up’ for it. Plus, the system will pass during a timeframe when temperatures are normally colder anyway (at night and early morning!).

We have quite an interesting scenario taking shape for the end of the week. The surface low on Thursday into Friday will take the classic track that favors significant winter weather across the Southeast. However, the pre-existing air mass across the region will only be marginally cold. Although colder air will get wrapped around the backside of the storm system, even it will be marginal. As a result, most regions across the Mid-South and western half of the Southeast region will likely just get a nasty, cold rain on Thursday.

Snow accumulation forecast for late-week winter storm

Snow Accumulation Forecast (Attempt #1)

  • I included a 5–10+ inch accumulation zone in the mountains of Georgia, South Carolina, North Carolina, and Tennessee, where soil temperatures are already relatively cool and low-level temperatures should be sufficient for snow (or a rain to snow transition).
  • I expect noteworthy accumulations to fall across the Cumberland Plateau, far northern Alabama, northern Upstate South Carolina, and western central North Carolina. A transition of rain to snow will likely occur as the mid-level and surface low wraps around colder air.
  • Far southeastern Kentucky and lower Virginia could get accumulating snow; however, if the surface low jogs slightly south, most precipitation will remain south of the area.
  • I outlined a region in pink, where this storm system could potentially bring unexpected accumulating snowfall. I currently have included the northern metro of Atlanta in this zone. Again, strong forcing will need to offset the very marginal air mass in place. Otherwise, expect a cold rain.
  • I expect only a cold rain across the rest of the Southeast and Mid-South.

Please stayed tuned for subsequent forecasts on this potential winter storm. Don’t forget to download our Southern Snow app. Our app provides you with snow forecasts from both Firsthand Weather AND your local National Weather Service office. Check it out!

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A response to questions about snow next week

Many of you have heard rumors of snow. Let’s talk about that. We’re over 3 weeks away from the start of meteorological winter, yet next week’s setup is very impressive for this time of year. In my opinion, the real story will be the cold. Most regions along and east of the Rockies will experience temperatures that would be expected during the winter.

Projected temperatures at 7am ET on Nov. 13 2019
Projected temperatures at 7am ET on Nov. 14 2019

Our first frontal passage is moving across the country now. If you check out current U.S. temperatures, you can see the cold front quite nicely. All of the snow talk is about the second cold front moving through early next week. That’s going to bring the real cold.

Basically, a strong mid-to-upper level trough is going to become oriented from southwest to northeast, extending as far south as Texas and Mexico. A strong cold front will be associated with the trough, and a surface low will likely develop to the east of the trough axis. It’s very possible that this surface low will track along the Gulf Coast states, exit off the Southeast coast and skirt parts of the East Coast.

There should be the development of precipitation along and ahead of the cold front. Due to the potency of the air mass moving in behind the cold front, most model guidance shows a transition from a cold rain to snow and sleet on the backside of the precipitation shield. As shown by the European model, you will notice accumulations occurring unusually far to the south. Other models have shown this as well.

Projected snowfall accumulations early next week, a forecast that will likely change significantly between now and then
Projected snowfall accumulations early next week, a forecast that will likely change significantly between now and then

When I’m looking for decent snow accumulations to occur farther south, I like to see a well-developed surface low pressure system. When a trough is oriented from southwest to northeast, the surface low generally remains weak. Thus, any frozen precipitation basically has to occur along a frontal boundary without any well-defined low. It does happen, but a setup like this doesn’t usually produce a big winter storm. Remember when Firsthand Weather busted horribly on a winter storm forecast last year? We expected accumulating snowfall to occur along a strong cold front without a well-developed surface low. We blew the forecast.

I’m a bit more concerned about temperatures dropping rapidly while roads are still wet. Oftentimes, roads are able to dry before temperatures reach freezing, but again, the air mass behind next week’s front is potent. Remember, temperatures will be at levels that we’d typically experience during winter. Some of the model guidance strengthens the surface low off the Southeast coast; thus, I’m not willing to discount accumulations being depicted across parts of North Carolina, Virginia, and northward along the coast just yet.

My hope is that many of you will get to experience a little snow. I suspect that accumulations won’t occur anywhere south of a line that runs from Oklahoma, central Arkansas, Tennessee, and North Carolina. Again, any concerns south of that line would likely be due to black ice, which can be quite dangerous.

I’ll post a more in-depth forecast on the site, if needed. I believe we need to watch everything a couple more days before we put out any detailed forecasts.

Pattern Change Along With Winter Storm Chances Increasing

European model cold

Despite the warmth that has prevailed across much of the eastern two-thirds of the United States this month, the configuration of the overall pattern has kept much of the U.S. in a very active weather pattern. The core of the warmth has been established over the eastern third of the U.S. with a tendency for troughing over the western U.S. This established a pattern that was favorable for systems moving into the Pacific Northwest, digging southeastward into the Plains, and then shooting back northeastward. This is the track that the most recent storm system will be taking, which is currently dumping copious amounts of snow over New Mexico and western Texas and was responsible for the deadly tornadoes in Dallas yesterday. This system is definitely not even close to being finished and will be bringing additional flooding, severe weather and winter weather to other regions of the U.S.

Pattern Change On The Way:

The coming pattern change that has been discussed for quite a while on Firsthand Weather is going to begin to emerge right around or just after the New Year. The persistent ridge over the eastern U.S. is going to start flattening out, and the temperatures are going to dip below average over much of the U.S. It’s important to realize that this transition is going to take some time, and there may be some volatility to the overall pattern before the anticipated colder pattern becomes established in the eastern U.S.

According to the forecast models, expansive ridging (blocking) is going to set up from the Pacific Northwest into western Canada and Alaska. This means that a general warming trend will occur in all of those regions, however it could take a decent amount of time before that warmth sets up in the northwestern U.S. into the Northern Plains. It’s important for me to point out that the forecast models have been all over the place due to this transition. While most meteorologists have gone from very warm forecasts to very cold forecasts (probably because of what the forecast models are showing), let me caution everyone that the long-range model guidance will likely not handle this transition well.

It still seems to me that the “real deal” cold won’t establish itself over the eastern half of the United States until mid-January or maybe even closer to February, but January is going to bring with it several Arctic intrusions with a number of winter storm opportunities. I think it’ll be important to have someone like the WDR Roofing Company – Cedar Park look at your roof and look at your emergency storm plans for this winter. It’s important to be prepared. As I’ve said since July, December would be warm, January would be a transition month, and February would be brutal (cold-wise). For all of you snow lovers out there, you actually don’t want such a cold pattern that the dominant storm track gets shoved too far to the south. In particular, that happened a few times last winter across the South, and I remember during the 2009-10 winter, there were places along the Gulf Coast (like Houston) getting snow before regions to the north were. In other words, you typically want to get just enough cold air for a winter storm!

Below is the projected temperature anomaly map for January 5th according to the European model. If you’re in the blue, you’re expected to get below average temperatures, and if you’re in the red, you’re expected to get above average temperatures. I’m more focused on the overall pattern than exact numbers that are shown in the legend on this map. Many of you are going to get your first real taste of winter cold as we start making this pattern transition.

European model cold

Southern Winter Storm Chances Will Increase Through January:

The overall storm track is about to make a change, and the focus area is going to be over region 8 and lower parts of region 6 in my winter forecast. I’ll have to keep an eye on some parts of region 7, too. I posted the winter forecast map below just so you could reference it. The western edge of region 8 has already verified quite nicely.

Final 2015-16 Winter Forecast

The active sub-tropical jet stream is going to remain established from Baja California, across Mexico, and into the Southern Plains and Southeastern U.S. As numerous cold intrusions will likely dig farther and farther south as we progress through January, this is going to open the door for the Southern Plains, Southeast, and even the Mid-Atlantic to be at higher risk of getting winter storms. In January, I don’t anticipate that any trough is going to dig so far south that the moisture fetch will be suppressed too far to the south.

Right now, nothing is showing up on the models for the first half of January, but I believe that the sub-tropical jet stream is a little too far to the south in the guidance. Despite the fact that nothing is really showing up on the model guidance, I am anticipating that a winter storm will occur within the first one to two weeks of January, potentially impacting parts of the Southern Plains and Southeast and maybe even the Mid-Atlantic. Pieces of energy are going to have the tendency to enter from the Pacific and cut across the southwestern U.S. or Mexico and move eastward. IF the cold air is sufficient, we could have our first winter storm on our hands (for the areas farther east that haven’t gotten anything yet), which could also have a severe weather component with it in the warm sector of the system.

In the long-range like this, it doesn’t really matter to me if the forecast models are picking up on an individual storm. Beyond 5 to 7 days, the forecast models are going to change so much that it’s not even worth pointing anything out, especially when the overall pattern is expected to change. What I try to do is identify the regions that will be more favorable for these kinds of events occurring, and that’s what I have done here.

Also, there could be an increased chance for lake effect snow events to occur due to this changing pattern, and with any system that swings down from Canada, this could bring an increased risk for parts of the Northeast to get some wintry precipitation. Also, it’s worth noting that parts of the Northeast will be impacted by the current winter storm that all eyes are currently on.

Of course, I will continue to monitor any individual storm system that comes up and will point those out to you as they start to show up. If anything changes in any way, I will definitely let you know, so please visit Firsthand Weather as often as you can.

Highly Disruptive Snowstorm Expected To Hit The East Coast

Hi-res 12z NAM Projected Snowfall Accumulations

November has been a fun month, but I’m ready for something new. As I mentioned on the Facebook page last night, most of you should have been prepared for this East Coast winter storm potential about two to three weeks ago if you have been following my forecasts, but I will admit that nailing down the specifics of this storm has been challenging. For those of you who have followed my forecasts for a while (particularly last winter), you already know that what I typically do is try to give you an early heads up on a potential storm or pattern change, and while I cover the specifics of a storm once it actually happens, it’s hard for me to put out very localized snowfall/rainfall maps since I’m currently running Firsthand Weather by myself. You can get pretty decent short-term forecasts from a lot of places, but what you can’t get are decent medium and long-range forecasts. That’s where I come in.

Before I talk about the Thanksgiving storm, I want to go ahead and give you an early heads up about a pattern change that will likely bring a large portion of the United States above average temperatures in early December after this next cold push. I want to make two special notes: this is only going to be a temporary warm-up, and we will be flipping back cold across the central and eastern United States later in December. This isn’t going to be some long-term warm-up like some of the long-range models have been projecting, and I expect the forecast models to begin to paint a colder picture after we get past this brief warm-up. One last thing to remember is that November was incredibly cold for most, so what may seem warmer is actually just a little bit above average. Nonetheless, warmer temperatures are coming for the central and eastern United States, so enjoy them because we have a brutal winter ahead.

Thanksgiving East Coast Storm Breakdown:

I wrote an article on Sunday that went into the meteorology behind what was going on, so in this article, I want to give you the details on what to actually expect from this storm. As I’ve already mentioned countless times, this is going to be a hugely disruptive storm for the Mid-Atlantic and Northeast on Wednesday going into Thursday, particularly for inland regions. Areas from northern Virginia through eastern Pennsylvania and inland regions across the Northeast will be getting the highest snowfall accumulations. Some of those areas could get anywhere from around 3 to 6 inches all the way up to a foot of snow or more. Adequate cold air will be available to support an all-snow event for those regions, and the snow to rain rations should be about 10 to 1, maybe even 12 to 1. That basically means for every 1 inch of liquid precip, you get about 10 inches of snow.

Areas closer to the coast, such as Washington, D.C. and New York City, are located in the zone that has been more complicated to forecast, and it has really come down to how much cold air will be available. There are two things that could lower overall totals for those located in these regions: many across this area may start out as rain and change over to snow and the overall snow ratios will be lower. Determining where exactly this snow/rain line will setup has been very tricky and will basically determine who gets pounded and who doesn’t. Most model guidance has come into agreement that these cities will not be the hardest hit but will get some decent snowfall accumulations. Just take note that this is a highly volatile storm, and anything could change even this close.

Places like Boston need to watch this as well since this is another city that is located on the borderline zone. Right now, it looks like the heaviest snowfall accumulations will be just west of the city, but regardless, things need to be watched. Areas across eastern Maine including the coast will likely get hammered with very heavy snowfall. I wouldn’t be surprised if some of those areas got well over a foot of snow.

This is the fun part about these types of storms because despite model agreement, you can still get those last minute surprises. Tomorrow is just not a good day to be traveling up the coast!

The North Carolina mountains could also get some accumulating snowfall with this system, but it’s going to be hard for areas outside of the mountains in the Southeast to get any measurable snowfall. However, as this storm strengthens and moves up the coast, there could be a transition to some wet snowfall outside of the mountains as temperatures fall across the non-mountainous regions. It’ll be interesting to watch, but it’s nothing that I expect to be hugely disruptive.

Below are the projected snowfall accumulations from the 12z NAM. Please note that snowfall totals are likely overdone along the coastal regions. Remember as I mentioned above that snowfall ratios may be lower than 10:1 closer to the coast, and this map is based on a 10:1 ratio. Also this has a difficult time taking into account any mixture or changeover of precipitation. Nonetheless, this should give you an idea as to where the heavy snows will most likely fall.

Hi-res 12z NAM Projected Snowfall Accumulations

Hi-res 12z NAM Projected Snowfall Accumulations

Be sure to follow Firsthand Weather on Facebook, Twitter, and Instagram. I will keep all of those pages updated throughout this winter storm and will put the larger updates on this site.

Big Snowstorm Next Week – Is It Possible or Only Hype?

Well it’s looks like we’re going to have to start keeping a close watch on a possible system next week that could give some areas the chance of snow. Several of the forecast models have been suggesting a pretty sizable snowstorm for portions of the Mid-Atlantic and Northeast mid next week, but let me be the first to warn you that everything has to come together almost perfectly for any type of major snowstorm to happen this time of year for this region. We’re still in the first half of November, and for any sizable winter storm to take place, the strength of the system, the timing of the system and the amount of cold air in place has to almost be perfect.

What has gotten my attention is the fact that the Euro, the GFS, and the CMC models are picking up on this system producing accumulating snowfall next week. Despite the consistency in some of these model runs, you must be very careful not to take anything too seriously. However, I think that it’s worth keeping an eye on simply because the models keep hanging onto the possibility.

12z GFS

The 12z GFS run from earlier today shows impressive snowfall accumulations for next week.

Now if you have been keeping an eye on the GFS ensembles, it is coming up with a plethora of possible solutions to next week’s system and possible outcomes. Some have the rain coming in before the cold air moves in, some have the cold air moving in earlier with heavy snow to follow, and some even keep the area dry and warm. With this being a week out and with us still being in early November, it’s hard to predict anything like this with any certainty, and the chances of something like this occurring are quite low. With that said, the weather has its way of throwing us for a loop so I’m not going to ignore the possibility regardless of how low it may be.

If we get a couple of days down the road and we continue to see the possibility of this winter storm occurring, then we’ll start discussing what needs to come together to make this happen. One thing to keep in mind is that the North Atlantic Oscillation (NAO) is currently positive, but by the time we roll around to next week, it will likely be in the more neutral state or even slightly negative. This would increase the chances of having some colder air pushing further south into these regions next week, but it’s also worth noting that the Arctic Oscillation (AO) will remain very positive during this time.

Just a quick warning: be wary of the Facebook and Twitter pages out there that are calling for a snowpocalypse for next week. Even some of the meteorologists out there are causing some unnecessary hype. Like I said, it’s worth mentioning and keeping an eye on, but by no means should we be forecasting a major winter storm just yet! Hopefully things will continue to remain interesting as we get closer to next week.