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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Updated Snowfall Forecast

We continue to monitor the chance for snow across much of the South and Southeast from Monday night into Tuesday. Most of this region will see the opportunity for snow accumulations that could impact travel. The worst travel conditions appear to be on Tuesday from northern Louisiana eastward into northern Georgia.

The first areas to experience snow will be far eastern Oklahoma, northeast Texas, Arkansas, western Tennessee and northern Louisiana by late Monday night. The rain & snow will move east and southward by early Tuesday morning into central Tennessee and parts of Mississippi (see Fig. 1) before moving further east into parts of Alabama and Georgia later on Tuesday (see Fig. 2). Parts of upstate South Carolina and North Carolina should get in on the rain & snow later in the day on Tuesday (see Fig. 3).

Fig. 1: Future radar late Monday night (please note: this should be used as an estimate–exact placement of precipitation may change)
Fig. 2: Future radar early Tuesday morning (please note: this should be used as an estimate–exact placement of precipitation may change)
Fig. 3: Future radar Tuesday afternoon (please note: this should be used as an estimate–exact placement of precipitation may change)

Accumulations do look likely from late Monday though Tuesday. The event being a few days out makes it extremely difficult to forecast snow accumulations, however. There are two negative factors for accumulations. I) Monday (the day before the snow) will be warm across this region, which will lead to warmer ground temperatures, and II) the window for snow is only about a 4-6 hour period. Even with these two mitigating factors, this event will be the best chance so far this season for accumulating snow across the South and Southeast.

The snow rates should exceed melting and the best chance for accumulations will across northern & central Mississippi, Tennessee, northern & central Alabama, northern Louisiana and northern Georgia. Guidance is evening indicating some instability, which could lead to convective banding of snow (this is where the heaviest snow totals are possible). It is too difficult to pinpoint where those bands may setup. That is almost a nowcasting scenario. Secondly, areas that see snow pre-dawn on Tuesday will have the best chance to see accumulations and nasty road conditions. Even though it is difficult to forecast snow accumulations this far out, I wanted to provide you with a second preliminary snow accumulations map (see Fig. 4). Please note, this will likely change over the next 48-72 hours as we get closer to the event. It is possible the polygons may need to me reduced or expanded, and snow totals may need to be increased or decreased.

Fig. 4: Preliminary snow accumulation map

The South and Southeast are not the only regions that have snow in the forecast. Coastal areas of North Carolina and Virginia may see snow beginning Monday due to a coastal low that will quickly deepen off the coast. This could allow a band of snow to setup from Virginia Beach down into eastern North Carolina. If this happens, it is possible heavy accumulations may occur, which is why this small area is included in the 2-5″ zone. It should be noted, most numerical guidance indicates the low will be too far off shore to aid in precipitation chances for this area, but we believe the low may closer to the coast, thus, have reflected this in the snow accumulation forecast. Regardless, snow chances increase for this area by Tuesday night into Wednesday. Those snow chances also increase for the rest of the Mid-Atlantic and the Northeast by Wednesday. Parts of the Northeast, Great Lakes and Ohio Valley will see multiple snow opportunities from Sunday through Wednesday so accumulations are likely (see Fig. 5). More than one foot of snow is possible for parts of the Great Lakes region where lake effect snow band establish themselves.

Fig. 4: Preliminary snow accumulation map

Please keep checking back for updates as this is a fluid forecast and changes may be needed!