This forecast is a follow-up on Matthew Holliday’s forecast from last night in regards to the winter storm that may impact parts of the Southern Plains and South/Southeast. There is still great uncertainty regarding the evolution of the winter storm late this week into the weekend, but I’ll discuss what we know and try to explain the pattern leading up to this potential event.
The guidance is struggling with consistency in regards to the placement of synoptic features leading to a potential wintery shot for low-latitudes. The thinking as of tonight (Tuesday), a trough will dig into western Texas late in the week. As the trough digs further into Texas, a surface low will develop along the north-central/northeast Gulf Coast. This will setup precipitation chances for parts of the Southern Plains and Southeast. A cold airmass will be oozing into the area at the same time, which will setup an area of snow, and likely an area of snow/sleet mixture.
A cold front has moved into the region today, but even colder air will settle in later this week as a reinforcing cold airmass moves into the area on Thursday. The thermal profiles with this aimrass will be conducive for wintry precipitation. The forecast soundings show mainly a snow profile for much of the Southern Plains with the potential for a snow/sleet mixture towards I-20 in northern Texas/northern Louisiana.
The first chance of light wintry precipitation will occur late Thursday into Friday for the Texas Panhandle, Oklahoma, Arkansas, northern Texas, and northern Louisiana in response to a weak disturbance causing lift; along with a band of frontogenesis due to a relatively defined thermal gradient associated with the reinforcing cold airmass This will act to squeeze out any moisture in the atmosphere; however, the precipitation will be light and brief due to the dry low-levels. Any precipitation should be light and begin in the Texas Panhandle and central Oklahoma/Arkansas, then slowly move southward into northern Texas. Forecasting snowfall totals is extremely difficult this far out, but it appears the snow should remain light. A dusting to 1” cannot be ruled out. It should be noted, if this band of snow moves slower than expected, or the frontogenetic area is more enhanced due to a larger temperature gradient than forecast, snow totals may increase just north of I-20. This will be monitored.
A second snow threat may develop across far eastern/northeastern Texas late Friday night into Saturday as the trough moves across the area. The trough appears to come into the Southern Plains at a positive tilt. This tilt is the least impressive in regards to precipitation chances, but should aid in light precipitation—especially east of Texas. This second threat is more questionable because it’s a battle between dry air. It will also be important to monitor when and if a weak surface low develops near the Gulf Coast. Right now, it appears a low will develop along the north-central/northeastern Gulf, which is too far east to aid in more precipitation for Texas. Southern Arkansas and Louisiana should see light snow, and a light snow/sleet mixture due to this weak low.
South and Southeast:
The aforementioned disturbance trekking across the Southern Plains late Thursday/early Friday may generate light snow/sleet north of the I-20 corridor in Mississippi and possible into far northern Alabama as well. The second threat, outside of the small band in Mississippi on early Friday, begins Saturday for central and southern parts of Mississippi, Alabama, Georgia, and eventually into South Carolina and parts of North Carolina.
As the trough moves east of out of Texas, it should become more neutrally tilted and a weak surface low may develop along the north-central/northeast Gulf. This low may slightly deepen as it begins a northeastward trek into the Southeast, which will wrap moisture into the cold air, and likely create an area of wintry precipitation for the aforementioned areas. It’s too early to determine how much snow will fall due to many unforeseen variables that will come into play. The evolution of the low (if it develops), the track, the position and depth of the cold airmass, and moisture are all critical in determining which areas will see snow, which areas will see a snow/sleet mixture, and how much may fall. It does appear some light accumulations will occur across the South and Southeast, however.
This map shows which areas I am watching for potential winter weather impacts late week into the weekend. Please note, this area will be updated throughout the week, and does not mean accumulations will occur. It’s entirely too early to forecast snowfall totals this far out.