Let’s address the Southeast snow rumors

There have been a ton of questions flooding into the Firsthand Weather inbox about the potential for wintry weather this week across the Southeast. Let’s address this fluid forecast that has many questions. We are closely monitoring the potential for wintry weather this week across parts of the South & Southeast. There are two shots for a wintry mixture across the regions. The first shot at a wintry mixture begins the first-half of Thursday for far southern & eastern Tennessee, far northern Mississippi, far northern Alabama & northern Georgia. A modified Arctic airmass will move south through the region late-Tuesday into Wednesday allowing temperatures to quickly tumble. 

A general uptick in precipitation begins late-Wednesday as two upper-level disturbances approaching the South. A southern-stream shortwave will move in from the southwest at the same time a northern-stream trough will drop toward the southeast. This will help aid in the development of a large shield of precipitation across the South. This shield of precipitation will advance east overnight Wednesday into Thursday. As the precipitation advances east, an Arctic high will build in from the north, helping to reinforce the cold air. With this reinforcement of cold air, will be extremely dry air throughout the entire column of the atmosphere; acting to help shut down precipitation chances. The main question: is there enough moisture left as the cold air moves in to support wintry weather? This is the classic race of moisture vs. cold air. It does appear there may be enough moisture around to allow a brief rain/snow mixture across far southern Tennessee & far northern Mississippi early Thursday before spreading east into eastern Tennessee, far northern Alabama & northern Georgia later in the day on Thursday. There are still a lot of questions so it’s too early to address accumulations. With that said, it appears no major accumulations are expected.

The second shot for snow exists farther east across the Southeast. The same upper-level disturbance will move east throughout Thursday. This trough will allow a surface low to develop just off of the South Carolina coast. This low should be close enough to the coast to pull moisture into the Carolinas late-Thursday. At the same time, the Arctic high will build in, allowing cold air to possibly undercut the moisture. One tricky detail is just how much the terrain slows down this reinforcing cold airmass. Arctic airmasses are dense, thus shallow, meaning terrain can drastically slow down the movement. This could protect the Carolinas from wintry weather. Right now, however, it does appear enough moisture will be in place as the cold air moves in to generate a rain/snow mixture across Upstate South Carolina & North Carolina. It is too early to forecast accumulations for this area.

To sum it up: yes, there is growing concern that parts of the South & Southeast may see snow Thursday. The best chance will be across far northern Mississippi, far northern Alabama, northern Georgia, far southern & eastern Tennessee, Upstate South Carolina & North Carolina. It is too early to address accumulations at this point so keep checking back for updates.

The images provided should be used as a tool to evaluate the timing & expanse of the precipitation shield, and is simply output from ONE model. Other models are showing a similar output. Keep checking back as this will be updated as the event nears.

Snow possible for parts of the South

Monitoring the potential for a light rain/snow mixture across parts of Tennessee, Mississippi, Alabama & Georgia late-Thursday into early-Friday. An upper-level trough, which helped spark severe thunderstorm on Wednesday, will move across the mid-South on Thursday.

On the backside of this trough, atmospheric temperatures (from the surface to where the jets fly) will plummet throughout Thursday. This will help set the stage for temperatures supportive of wintry precipitation. While the colder air will also be drier, a secondary area of enhanced-lift will dive southeast, placing the region in a favorable region for light precipitation to develop. While moisture is limited, guidance indicates some mid-level moisture moving in with this area of lift, which should be enough to allow a rain/snow mixture to reach the surface.

Marginal surface temperatures & meager moisture will prevent major accumulations. However, light accumulations (generally under 1/2″) are possible but a few areas may see up to 1″. Higher amounts possible on the west-facing slopes of the higher terrain in Tennessee & North Carolina. This is an evolving forecast so keep checking back for updates!

Significant winter storm to impact the Southern Plains

High-impact winter storm expected to dump heavy wintry precipitation across parts of the Southern Plains Tuesday into early Thursday. The stage is being set for this event as a strong Arctic cold front is oozing south through Arkansas, Oklahoma and Texas. This modified Arctic airmass will continue to advance south on Tuesday. At the same time, a potent upper-level system will approach the Southern Plains from this west. This will aid in strong lift, leading to widespread precipitation across parts of Texas, Oklahoma, Louisiana & Arkansas.

Northern & central Texas will see a mixture of sleet & freezing rain late-Tuesday into early Wednesday, while locations farther north will see snow. As the cold air deepens, the sleet/freezing rain will transition to light snow through Wednesday.

Locations even farther south will see a wintry mixture Wednesday evening into early Thursday morning as a secondary area of lift moves over Texas. This lift will try to squeeze any remaining moisture out of the atmosphere. At this point, temperatures will be significantly colder throughout the entire column of the atmosphere, leading to a sleet/snow mixture for areas as far south as Austin & College Station, Texas. It is possible this wintry mixture will spread into southwestern Arkansas & northwestern Louisiana early Thursday morning.

Accumulations are likely for parts of the Southern Plains that will lead to travel issues. A Winter Storm Watch is in place for a large part of the region. This Watch will likely be upgraded to Warning on Tuesday.