George001

The gfs op hasn’t led the way with anything, it has been all over the place. Lows can’t ram into a massive block, the GFS is acting like the blocking doesn’t exist and keeps cutting the lows to Wisconsin, garbage model.

I would like to see the trough out west weaken though. It doesn’t need to be great but I would rather see a slightly negative PNA than a very negative one.

not bad

Euro is trying for a Miller B in that timeframe

The blocking is still there, the epic pattern just got delayed some. That doesn’t mean it won’t happen.

Easy just ignore the GFS because it sucks, it has a super nino pattern despite it being a moderate La Niña.

I’d lean towards the European guidance because it has been more consistent. The GFS is completely lost.

Storms cannot cut when there’s blocking this strong, the problem is the airmass sucks, and the ocean is still really warm. The earth is warmer than it used to be so more has to go right. Even a perfect track isn’t enough with the lack of cold, the low needed to deepen a lot and create its own cold air. Ridging doesn’t connect from the SE to Greenland, the block suppresses the SE ridge. NNE will still probably get lots of snow, but for the rest of us yeah the epic pattern looks like it’s going to be delayed. Honestly for those of us not in NNE the delay is good, because it means the window for the epic period is closer to peak climo when it comes. That said, the 13th threat hasn’t gone anywhere. The 10th is probably cooked though.

The surface looks odd, there are 3 lows. I would think they would combine into one big low. The location of the rain snow line is very reasonable though considering the airmass and ocean temps. Interior areas have a really good shot with this threat, those of us closer to the coast I think will have some ptype issues. Maybe something like March 2017 or the Feb storm a couple years ago where my area got 8 inches, and 20 min NW got a foot and a half.

Euro whiffs the first threat but the h5 looks great for the second threat.

I’m still keeping an eye on it but I like my chances for the 13th better. The airmass is better by then and the blocking is in a better position.

That’s a good point, climo is more hostile now than it is in early March especially for the coast. Even my area which isn’t right on the coast has done a lot better in March than December lately. December climo isn’t favorable to begin with but It feels like climate change has made it even less favorable. The warming oceans is a double edged sword, it can help storms bomb out and give crazy amounts of snow if the airmass is cold enough, but when the airmass is marginal it makes it a lot harder, even a bit of onshore winds and the coast is cooked.

To everyone worried about thermals, I wouldn’t worry about it as long as the low location is good and the low is really strong. The low can create its own cold air, I’ve had people tell me this doesn’t happen but I’ve seen storms where it works out. March 7th 2018 was heavy rain for several hours where I live, but the low bombed out and dynamically cooled the column. The initial airmass sucked, but due to the low creating it’s own cold air via dynamical cooling I ended up getting around 8 inches of snow, with areas NW getting nearly 2 feet. That is what we will be relying on for the first threat. It’s low probability it will strengthen enough to create enough cold air to give significant snow, but I wouldn’t rule it out. The second and third threats have a better shot.

I’m not worried about the airmass, if the low location is good and the low strengthens enough the snow will come. The low will create its own cold air.

It’s the gfs so it’s probably wrong

Euro whiffs with the first storm but looks great for the 2nd one on the 13th. I’m interested to see what the EPS says.

Though I wouldn’t mind seeing the epic pattern delay a couple more weeks, that would mean my area has a better shot in the early part of the pattern as well as later on.

That’s not really true, the models have been going back and forth but the H5 looks great on the ensembles for the 13th threat. There are a lot of indies taking the low down to the 970s and some to the 960s. The interior is favored for that one, but if the low gets that deep the coast could get a lot of snow as well. I agree that the 3rd week to 4th week is when the coast will start having better chances though.

Yeah the polar vortex splitting isn’t always good for us, it can actually be bad. A couple years ago the polar vortex split to the wrong side of the globe and we had a really mild winter (2020 I think it was). I read that this year is expected to be a weak polar vortex based on the latest guidance, but no polar vortex split. I don’t even think this polar vortex event is expected to be an official SSW, just a bunch of smaller disruptions to the polar vortex instead which can be just as good.

Yeah, the models have been going back and forth on the starting date of the pattern change. I haven’t really noticed a delay, it moved from the 13th to the 10th and back to the 13th again on the ensembles. Even if it does get delayed a bit more on the models it’s not a big deal, and if anything those of us closer to the coast should be rooting for a delay to like the 20th or so.

That’s right. Lows don’t ram into massive blocks like this one.

Yeah there’s no reason to worry. As long as there is blocking it will snow. Not every threat will work out but we will have enough chances that the odds of us making it out of December without at least one big storm is very low.

Fair point, but this isn’t a run of the mill -NAO either. Also, the Feb 2018 SE ridge was even stronger than this one. Temps got up to 80 in Feb, yet the blocking still beat it down some. It took time, like this one probably will. That’s why the first 10 days or so of December are expected to be mild, and the first storm is lower probability than the latter 2 over the next couple of weeks.

I might stop by, I’m not sure yet though. I’ll have to check my schedule to see if I can make it or not.

We want the SE ridge to prevent suppression. We don’t need help with the PNA, it can snow with a negative PNA and it can snow a lot. December 2010 had a trough out west as well.