The models have gone north. Way north.
If you went to bed last night feeling confident about where this storm was headed, the overnight runs just scrambled the picture. The European model shifted nearly 200 miles in 12 hours. The GFS came with it. So did the NAM, the ensemble means, and even the AI guidance. When you see that kind of agreement across the board, you have to pay attention.
This doesn't change the big picture. A major winter storm is still coming Friday through the weekend. We're still looking at around 160 million people under the gun for wintry precipitation by Sunday morning. Winter Storm Watches now stretch from New Mexico to Tennessee and they'll keep expanding today.
What's changed is where the bullseye lands. And for a lot of people in the transition zone, that matters a lot.
Will this shift again? Probably. We're still 48 to 72 hours out and the northern stream energy hasn't fully consolidated yet. I expect we'll see more wobbles in the coming model runs. When that happens, I'll tell you. That's how this works. We follow the data where it goes, update the thinking, and keep you informed with each shift. For now, this is where the models are pointing.
What's Driving The Shift
The ejecting Pacific low is phasing faster with northern stream energy than models were showing 24 to 48 hours ago. That northern energy is currently strung out across western Canada into the Arctic. When it consolidates and merges with the southern stream, it amplifies the whole system earlier in its lifecycle. That shoves the storm track farther north by strengthening the downstream ridge.
This is what just about all the 00z models are trending towards now. Generally a clean sweep. The deterministic physics based models, ensemble means, and AI guidance all shifting north with the storm track.
So how confident should we be in this trend?
Given the nearly unanimous agreement and at least a couple model runs in a row showing the same thing, it does seem like the shift has merit. But overall run to run consistency has shown pretty large swings with the exact handling of both the southern and northern stream energy. The exact details of these features are far from settled, especially the northern stream energy which is still strung out across western Canada.
I tend to think the unanimous model trend could be a slight mirage. It suggests more confidence in a solution than actually exists at this point. Either way, we get a widespread and major winter storm with significant impacts regardless of these details. They just determine exactly where the maximum snow and ice totals end up.
The Winners And Losers Of The Northern Shift
The northern trend is good news for the I-95 corridor. Washington, Baltimore, Philadelphia, and even New York City are now being pulled into the significant snow zone. The NWS New York discussion mentioned a plowable snowfall event as possible. That wasn't on the table 48 hours ago.
The northern trend is less good news for the Deep South and parts of the Mid-South. A farther north track brings warmer air aloft faster, which shifts the snow/ice/rain lines. Areas that looked locked in for heavy snow are now seeing more uncertainty about precipitation type.
For Kentucky, this is the key issue right now. The latest data suggests all-snow chances are decreasing as the system trends north. A warm nose intrusion is increasingly likely, which could cap accumulations and introduce ice to the forecast. I think holding off on specific snow amounts is smart until we see if this trend continues or if things tick back south in later runs.
Southern Plains: Friday Into Saturday
Winter Storm Watches are up for most of Oklahoma, large portions of Arkansas and North Texas, and into Tennessee and New Mexico. Upgrades to Warnings are likely today.
Snow develops across the Texas Panhandle and Southwest Kansas late Friday morning, spreading through Oklahoma and into the Ozarks by evening. North of I-40, this is an all-snow event. Temperatures will be in the teens and 20s through the whole column. Given that cold, snow to liquid ratios will run well above normal, so even modest liquid equivalent translates to efficient accumulation.
South of the all-snow zone, things get messy. A pronounced warm nose aloft will override sub-freezing surface temperatures from West Texas into Arkansas. That means freezing rain, sleet, and mixed precipitation.
The NWS Fort Worth has Winter Storm Watches up for Dallas-Fort Worth from Friday afternoon through Saturday night. Texas Governor Abbott has activated state emergency response resources. ERCOT has issued an Operating Condition Notice.
Tennessee Valley: The Tricky Spot
The NWS Nashville has Winter Storm Watches up from Friday night through Sunday. They're expressing high confidence in accumulating snow but flagging low confidence in the freezing rain component.
What looked like a 6 to 10 inch snowfall corridor across Middle Tennessee yesterday is now more uncertain. The faster phasing means warmer air aloft arrives sooner, potentially converting snow to sleet and freezing rain before temperatures cool enough for a return to snow.
The NWS Nashville snow probabilities tell the story. North of I-40, there's a 50 to 70 percent chance of 6 inches or more. South of I-40, that drops to 30 to 50 percent. The difference is where the warm nose sets up.
Mid-Atlantic: Now In The Crosshairs
This is where the northern shift matters most.
Roanoke, Richmond, Norfolk, Washington. These areas are now solidly in the significant snow corridor. Local NWS offices are calling this a split flow pattern, something we haven't seen yet this winter, and historically favorable for notable winter storms in Virginia.
The NWS Richmond is calling for 3 to 12 inches with the caveat that more than 12 inches is on the table. They've also flagged ice accumulation potential if snow transitions to freezing rain Sunday afternoon and evening.
This system will have plenty of cold air to work with. That leads to higher snow totals with more time in the falling snow. Dangerous to impossible travel is expected Saturday through Monday. Temperatures stay below freezing through Wednesday morning.
Northeast: Still Uncertain
The overnight Euro showed heavy snow expanding into NYC, Long Island, and New England. Very few guidance products were showing this 24 hours ago.
But I would be careful with snow maps for the Northeast this far out. There's still significant uncertainty with the amplitude and progression of both the Southwest trough and the north stream trough. Until we have a better handle on these features, we can't reliably rule out anything from no snow to over a foot between the NYC to Boston corridor.
Current thinking puts D.C. at 4 to 8 inches, Baltimore similar, Philadelphia at 3 to 6 with lots of uncertainty, New York at 2 to 5 but possibly higher if trends continue, and Boston at 1 to 3 unless we get secondary coastal development.
The WPC has scheduled airborne reconnaissance into the developing low. The Hurricane Hunters will sample the atmosphere to give forecasters better real time data on system evolution.
The Ice Threat
South of the snow line, a dangerous icing corridor is increasingly likely. This is the most hazardous part of the storm for millions of people.
Over the next few days you're going to see a lot of maps showing freezing rain QPF amounts. Some of these will look absolutely terrifying, with values of one to two inches or more. Be careful with those maps.
Freezing rain QPF shows how much precipitation falls in the form of freezing rain. That is not the same as how much ice actually accumulates on surfaces. Actual ice accretion depends on surface temperatures, wind, and precipitation rates. Those raw QPF maps will be overdone. A major ice storm is increasingly likely, but don't take those numbers at face value.
Areas most at risk include central Texas along I-20, the Ark-La-Tex region, northern Louisiana into Mississippi, northern Alabama through North Georgia, and the Carolina Piedmont from Charlotte to Raleigh.
Ice accumulations of a quarter to half an inch are possible across these areas. That's enough for widespread power outages and tree damage. Multi-day outages are a real possibility given that temperatures will remain below freezing for days after the precipitation ends.
The Cold
This storm isn't occurring in isolation. An expansive arctic high will dominate north of the storm track throughout the period. Wind chills of 40 to 50 below zero are expected in parts of the upper Midwest Friday and Saturday.
This cold air will bleed southward and eastward, keeping temperatures 20 to 30 degrees below average through early next week. Whatever falls is going to stay on the ground for days.
What I'm Watching Today
The 06z and 12z model runs will tell us a lot about whether the northern trend holds or if things tick back south. Precipitation type boundaries could still shift 50 to 100 miles. If you're near the expected snow/ice line, stay flexible.
There's also ensemble spread regarding whether a secondary coastal low could wrap winter impacts back into the Northeast early next week. Lower confidence scenario for now, but worth watching.
Bottom Line
This is a high confidence event for significant winter impacts across a large portion of the Southern and Eastern United States.
Plan for going days without power this weekend if you're in the icing zone. Expect school cancellations next week across a huge area. Do not plan a road trip this weekend. This could absolutely be a situation where people get stuck on the highway.
Finalize your preparations today. Check on elderly neighbors. Charge your devices. Stock up on essentials. Have a plan for staying warm if the power goes out.
If this trends back south and turns into less of an event for certain areas, I'll tell you. But right now the overall message is the same as yesterday, just with a different geographic emphasis.
Be ready.
