WxUSAF

Probably safe to say CMC is going to be our least favorite 12z model…

Not really. Although the objective stats have it better than the GFS typically now.

B/W maps are rolling…and yikes. They did not get the memo that 12z was supposed to stop the bleeding.

Did Canada’s computers break this morning?

Exactly that

Yes

Yup, I think that’s very much on the table. I think that’s pretty close to what last nights euro showed for many of us.

One small feature I’ve noticed this morning is the vorticity streamer oriented E-W between our shortwave and the upper low in New England and Atlantic Canada. On my phone so can’t post a graphic, but it shows up very clearly at 84hrs on the GFS, NAM, and Icon through the Great Lakes. Seems like it does help lower heights ahead of the storm. Not sure yet how much it may shift things, because it’s a subtle feature, but I’m going to watch that today.

That WAA snow will be a beast. Have fun Sunday afternoon/evening watching that rip, have some drinks and watch football, and go to bed before it flips. Great day!

End result is pretty similar to the last few GFS runs, but for this run at least, the stronger/slower/wester trend stopped. Maybe a blip, hopefully a start. But a step of that size each run puts us in great shape by Sunday

For sure. It’s 6-8 hours of thumping WAA snow then probably mostly dry slot.

6z euro only goes to 90 hours.

Totally agree. We’ve seen such huge shifts within 60 hours of storm start this year already! We’re at twice that range almost! This storm already had a massive shift in presentation yesterday! I’d say we have AT LEAST until the 0z Friday runs if not more time for positive shifts. That said, 0z euro is a solution I’d still pretty happily take for MBY…

As always with a coastal storm, there's 1000 moving parts and subtle changes can initiate huge sensible weather changes at any given location. In general, for those of us in the metro corridor, I think we want to look for a few things to make the storm more white than wet (in no preferred order): 1. Increase confluence and lower heights to our north/northeast. This would resist the N/NW motion of the storm and help lock in colder air longer. 2. Increase the forward speed of the storm. It still has been trending slower, which gives more time for our very nice antecedent airmass to move out. Speed it up and it's moving precip into a better airmass for snow. 3. Delay/weaken the northern stream shortwave in the Great Lakes that yanks it north/northwestward. Without this shortwave, this storm is probably a southern slider. We want it to just provide a LITTLE pull to get it up the coast, but not TOO MUCH that would make it cut to Cleveland. Clearly the trend so far has been too much phasing.

@LP08 it's that northern stream shortwave in Canada. In your map, it's up in western Hudson Bay and a piece breaks off and moves through the Canadian prairies and down into the Great Lakes. That yanks our storm west. Without, the Atlantic side blocking is probably sufficient to make it a southern slider that moves out to sea. We saw that with earlier runs. So the positioning and strength of that shortwave is key.

Last evening I was speculating whether the ensembles were "chasing" the Ops. 18z EPS seemed to go the other way, but the overnight runs definitely look like chasing is in progress. Still lots of time for this to wobble back the other way...or turn into congrats Detroit.

DT is riding the #snowtrain https://dtwxrisk.medium.com/tuesday-730pm-update-on-jan-15-16-east-coast-winter-storm-d46de7f907e8

Same. I was kind of wondering if the ensemble members were "chasing" the Op, but if that was the case, you'd expect the 18z GEFS to have looked at least more like the 12z Op (not that 12z and 18z looked that different). But nope...still almost entirely offshore. In general, this is still 5-6 days away, so ensemble means should be where to put your $$. But we have time to see if that's a bad bet.

This is an important point for sure, but the Euro/EPS and GGEM/GEPS having similar looking differences seems very odd.

It seems more than coincidental that the last 3 GFS runs, the GGEM, and the Euro have all been western outliers to their ensemble members. But I'm not sure how much can be chalked up to simple resolution differences since the EPS members are run at comparable resolution to the GFS operational. So I'm not sure what's going on. Luckily this is still 5 days out so we have plenty of time to sort it out.

From the pit of despair, to the top of the mountains, to off the cliff in 24 hours. Never change, weenies.

That storm had the WAA snow come in like an absolute beast. The solutions for the 3 big globals today certainly made me think that there would be a heavy front end snow dump verbatim.

Nope. If you believe the snow maps, it sweeps through with 3-6”.

CCB megadeathband on the backside. Might just stay NW of the metros