We've been watching this one for days. Now it's time to get serious.
Model guidance has finally locked onto what is shaping up to be a significant, potentially historic coastal winter storm affecting the Carolinas and southern Mid-Atlantic this weekend into early next week. The National Weather Service has started messaging on this threat, and for good reason. This is a setup that demands attention.
Here's everything we know as of this morning, and what still remains uncertain.
The Setup
A potent closed upper-level low currently over the Tennessee Valley will pivot toward the South Carolina coast by Saturday night. As it does, rapid cyclogenesis will occur offshore. When central pressure drops at least 24 millibars in 24 hours, meteorologists call it a "bomb cyclone." This one has the potential to do exactly that.
An unseasonably cold Arctic airmass is already entrenched across the region, and that's the key to this event. The cold air in place means precipitation will fall entirely as snow across a huge area, including coastal locations that typically see rain during winter storms. Temperatures will be well down into the teens and 20s across the snow zone, supporting snow-to-liquid ratios in the 15:1 to 20:1 range. That means fluffy, efficient accumulations even with modest liquid equivalent.
Snow Expectations
The heaviest snowfall corridor is expected across eastern North Carolina and southeastern Virginia, particularly from Saturday afternoon through Sunday morning. Strong deformation banding combined with Atlantic moisture inflow supports high confidence in widespread totals exceeding 8 inches across this zone, with localized amounts of 12 inches or more possible near the Virginia Capes and Outer Banks.
But here's what makes this storm particularly dangerous. The rapidly deepening low will generate a tight pressure gradient with wind gusts of 35 to 50 mph. We're talking near-blizzard conditions with significant blowing and drifting snow and very hazardous travel. Visibility will be reduced to near zero at times in the worst of it.
Further inland, the South Carolina Midlands and central North Carolina are looking at a more modest 3 to 6 inches. Still enough to cause significant impacts in an area that doesn't handle snow well.
The Southern Appalachian Story
This storm isn't just about coastal cyclogenesis. Separate from the offshore low, strong north-northwesterly flow will drive a prolonged period of upslope snow along the Tennessee and North Carolina border counties. As the upper trough axis swings through Saturday into Sunday, orographic lift will pile up 4 to 7 inches across the higher elevations of western North Carolina and eastern Tennessee.
Light to moderate accumulations of 2 to 4 inches may extend into southwest Virginia and the southern West Virginia coalfields before forcing wanes early Sunday.
The Dry Slot Question
One thing that would give me pause if I were a snow enthusiast in, say, Raleigh. Setups like this can sometimes develop sneaky dry slots. When you have two main sources of forcing for snow (the upstate South Carolina mesolow to the west versus the coastal low to the east) you can end up with a "no man's land" in between where neither forcing mechanism delivers significant accumulation.
Raleigh could find itself in exactly that position. The most likely way to avoid the dry slot in the Piedmont is if the coastal low really cranks up and occludes faster, allowing heavy snow to expand from the coastal plain back westward. But we just don't know for sure yet. This is a very tricky forecast.
For practical purposes, if you're in central North Carolina, prepare for impacts but understand there's more uncertainty in your snowfall totals than locations closer to the coast or the mountains.
What About Florida?
This is pretty incredible, actually.
On the backside of this potent storm, Arctic air will swirl across the Gulf on Saturday night, stretching down the Florida Peninsula and causing wind chills to reach the 20s, teens, and single digits. As that freezing air glides over much warmer ocean waters, enough atmospheric instability may be sparked to cause Gulf-effect snow in a stretch from Apalachicola to Tampa. Same basic mechanism as lake-effect snow near the Great Lakes.
If a few flakes fly across this zone, it would be rare, but not unprecedented. Early Sunday, the air may be cold enough for snow to fall over the ocean about 100 miles north of the Bahamas. Believe it or not, it has snowed there before. Flurries were reported in Freeport in January 1977.
Coastal Flooding
Beyond the snow and wind, this storm brings a significant coastal flooding threat. Strong north to northeast winds will generate dangerous surf and storm surge along the immediate coast. Sunday looks particularly concerning for coastal flooding from the Outer Banks into the Delmarva Peninsula. If you're near the coast, this isn't just a snow event. It's a wind and water event too.
What I'm Still Watching
Despite the increasing confidence in the overall storm, several important details remain unresolved.
Exact placement of the heaviest snow corridor. The sweet spot for double-digit totals could shift 50 miles in any direction depending on how the coastal low tracks. If you're on the edge of the bullseye, stay flexible.
The dry slot over central North Carolina. As discussed above, the interaction between the upstate mesolow and coastal low creates genuine uncertainty for the Piedmont. Raleigh could see 2 inches or 8 inches depending on how this resolves.
Rate of cyclogenesis. A faster-deepening low that occludes quickly would push heavier snow westward. A slower solution keeps the jackpot totals confined to the immediate coast.
Coastal flooding magnitude. Strong winds are basically locked in, but exact surge levels will depend on the low's track and intensity.
Timeline
Friday, January 31: Arctic air continues to filter into the region. Conditions remain dry but cold.
Saturday, February 1: Snow develops across eastern North Carolina by afternoon as the coastal low begins to deepen. Upslope snow starts across the southern Appalachians. Winds begin to increase along the coast. Travel conditions deteriorate rapidly by evening.
Sunday, February 2: The system reaches peak intensity. Heavy snow and near-blizzard conditions continue across eastern North Carolina and southeastern Virginia through the morning hours. Upslope snow tapers in the mountains. Coastal flooding concerns peak. Storm begins pulling away toward the northeast by evening.
Monday, February 3: Storm exits toward the Canadian Maritimes. Bitter cold remains locked in place behind the system. Whatever falls is going to stay on the ground for days.
The Bottom Line
This is now a high-confidence event for significant winter impacts across the Carolinas and southern Mid-Atlantic.
If you're anywhere from eastern North Carolina through southeastern Virginia, treat this like the real deal. We're looking at the potential for blizzard or near-blizzard conditions with dangerous travel, power outages from wind and snow-loaded trees, and coastal flooding.
If you're in the Piedmont, prepare for impacts but understand there's more uncertainty in your specific totals. And if you're in western North Carolina or eastern Tennessee, you're looking at a respectable upslope event separate from the coastal chaos.
Do not plan a road trip this weekend if your route takes you anywhere near the coast. This could absolutely be a situation where people get stranded.
Finalize your preparations today and tomorrow. Charge your devices. Stock up on essentials. Have a plan for staying warm if the power goes out.
I'll continue to update as the models resolve the remaining uncertainties. The fat lady hasn't sung yet, and exact amounts are still coming into focus, but the overall message is clear.
