Snowfall forecast for this weekend's major storm, the first anywhere in the coastal northeast in several years, and probably the most widespread in a decade. We should see widespread 12-18" totals, but as we get closer it's likely there will be somewhere that gets 18-24" or more.

This really is a classic setup. That low developing off the Outer Banks and passing over the benchmark really brings back memories of other major storms we’ve had. If you got to handpick the storm track for maximum snow in SNE, this would be it. Should be fun!

The 2/17/03 storm lasted about 36 hours, part of why it was so impressive. Duration is also a question with this storm; some models shut precip off Monday morning, while others keep it going into early Tuesday due to a developing surface low. This obviously impacts totals greatly

Presidents’ Day Blizzard of 2003 is my best comp for this storm. That one was a bit beefier than models show here, but the track and overall setup is similar. That one also featured very cold temps before the storm, with Boston hitting 0 the day before, and ratios were 18:1.

Boston has seen 4 storms of 12”+ in the last 10 years, with none since the blizzard in 2022, and hasn’t seen a 6” storm since that same winter. Very good chance that 6” streak is snapped this weekend, and also a pretty good chance of joining this 12” list.

DC has gotten 6 storms of 10”+ since 2000. None since 2019 (10.2”), and last foot of snow was the blizzard of 2016. Wouldn’t surprise me at all to see those streaks broken this weekend.

Another fun part of this storm is how cold it’s going to be. Largely independent of whether we actually get precipitation (track-dependent), it’ll likely be in the single digits on Sunday. It’d be like 2/15/15 type fluff if we do get snow.

Our next storm chance comes next Sunday, and yet again it’s a battle between AI and physics models. A large elongated wave will move across the country fueled by a strong temperature gradient. Before it hits the east coast, parts of the south have a good chance for more snow.

While we could be losing prefrontal snows, our actual coastal storm took a step in the right direction. Our trough has been a bit sharper and more negatively tilted throughout the day today, which is something RRFS saw well in the mesoscale modeling department. Means more

Pretty significant trends overnight with most models now in agreement on a more expansive precipitation shield. This means most of the region should see accumulating snowfall, possibly plowable in some areas. Model blend now vs. 6 hours ago shown as an example of the shift.

While we’re still watching Sunday, the pattern is pretty interesting looking ahead. Next storm chances come Jan 25-26 and Jan 29, but in between we could see some of the coldest air since 2023 with a real possibility of going below zero, especially if there’s snow on the ground.

Pretty crazy battle going on right now between AI and their physics-based counterparts for Sunday. They should come into better agreement tomorrow, but one camp is going to be very, very wrong. Feels like we’ve been talking about these massive medium-range differences all winter.

These favorable dynamics coupled with very cold temperatures throughout the column also mean ratios will be quite high. This high end scenario is shown well by the HREF, though it’s still quite unlikely at this point (<10% imo).

These mesolow setups are tricky. The most likely scenario is sort of a dud with a coating to an inch for most, maybe 1-3” on the Cape, but they do bring a big boom scenario. Given such favorable dynamics, a strengthening low like that can bring heavy snow. Very high end is 4-6”.

Should see a few hours of snow late tomorrow night. Models have trended stronger with the mesolow, meaning there’s a little more moisture, and upper level dynamics are good. My guess is most places see a fluffy inch (2-4” Cape and Islands). Timing is ~11 pm - 5 am.

Very favorable pattern coming up from January ~5-12 and beyond. There is a ton of model variance for specific threats, but any disturbance that comes by has the chance to turn into a strong storm. We should get one every 2-3 days, and it wouldn’t surprise me if one was a bomb.

0.9” in Cambridge as of 11:30 pm - virtually all accumulation came in the last hour. 19° and moderate snow currently. @WX1BOX spotter ID 20-373

Pretty good consistency as our event gets underway…

HRRR is showing this to some extent with a second band of higher totals and less in between (still snowing E. MA). Actual gradients will be sharper and the location could change, but definitely the possibility for a secondary local maximum under that other FGEN band.

Easy 2”/hr signal in western New England tonight, with great lift aligned with the DGZ and very cold temperatures. Under this band is where we’ll see the 10-12”+ totals.