A coast-to-coast winter storm, which will track from the West to East Coast this weekend, will impact much of the country with snow, freezing rain, or heavy rain through early-next week. Now while uncertainty remains as we look ahead into the weekend, cities in the Southeast like Charlotte may be at risk for an unusual several inches of early-December snow.
Two determinants of snow is whether the air will be cold enough and where the moisture will be located. As we track a low pressure reform over Texas and intensify as it tracks along the Gulf Coast (picking up a good deal of moisture from the water), we’ll watch it interact with freezing to near-freezing air on the northern extent of the low. This is the area where snow-related weather will be possible, but also where the forecast will be most uncertain, especially in the Southeast.
This Thursday, the weak low pressure will traverse across the Southwest, bringing mountain snow to parts of the Four Corners states. This will drop a couple inches of snow in higher elevations in the Four Corners states, a common occurrence for them at this time of the year . It is not until the weekend when the low will enter the southern Plains, potentially bringing more severe winter weather.
Beginning late in the day Friday or Friday night, the rain across the region will transition to either snow and/or freezing rain from eastern New Mexico through the Texas Panhandle and into western and central portions of Oklahoma. This snow will be heavy in some cases, especially in the panhandle of Texas as snowfall rates potentially exceed 1 inch per hour. Just south of there will be the greatest risk for freezing rain, from the southern part of the panhandle into central Oklahoma. These areas will have the greatest shot for over 0.10 inches of ice accretion, but keep in mind this icing risk from this storm will span from New Mexico through the Arkansas-Missouri border, so a large area will be in the threat zone for freezing rain.
Meanwhile to the south, heavy rain will be falling on Friday in central/southern Texas and eventually into parts of the Gulf Coast states. Several inches are likely to fall, especially in eastern Texas. In central and southern portions of the state, isolated severe weather will even be possible. This will not be an outbreak of widespread severe weather, rather damaging winds, hail, and tornadoes could be produced locally due to the dynamics of this storm.
As we get into Saturday and into the night, the low pressure will continue to intensify as it hits the Gulf Coast, bringing heavy rain and thunderstorms to the Gulf Coast states and Southeast. To the north, there will be wintry weather due to the interaction between freezing air and moisture. Snow and even some sleet and/or freezing rain will be possible between Saturday and Saturday night from eastern New Mexico through much of Oklahoma, northern Arkansas, and possibly into the Memphis area. Depending on how much cold air gets infused into the system, there may even be some snow in parts of the Tennessee River Valley. Looking farther east, we’ll also begin to see snow break out as early as Saturday afternoon in the southern Appalachian Mountains. Snow, which will become heavy overnight Sunday, is expected in the southern mountains but also to the east, affecting parts of upstate South Carolina and much of North Carolina, especially western North Carolina. This snow will be taking place during the weekend, but there will still be travel issues and therefore it is advised to stay off the roads Sunday, especially given the fact that several inches of accumulation is expected.
This winter storm will really peaks on Sunday as the low pressure moves off the Southeast coast. Cold air and moisture will still be funneled into the Southeast, keeping the snow around western North Carolina, southern Virginia, and the southern Appalachian Mountains. During this point in time, the best risk for heavy snow will be in the mountains and across western and northern parts of North Carolina. As night arrives, the bulk of the precipitation will begin to move offshore, so that will shut much of the snow off, but there will still be some towns that will continue to experience the snow, especially in the mountains.
By Monday morning, there will be lingering rain and possibly snow showers across the Southeast, but additional snowfall accumulation is not expected. It will also be interesting to watch the evolution of the low pressure as the model guidance does suggest that a second low may branch off of the primary one, keeping the precipitation around in parts of the Southeast as late as Tuesday. There are also some signals that hint at the low moving far enough to the north once offshore to affect parts of the Northeast, but that chance is very low at this time. About all of the ensemble members of the numerical models keep this coastal low well offshore for no direct impacts.