psuhoffman

I think the uniformity can be taken as a sign a somewhat similar setup will happen. If a random model shows a storm at 160 hours there have even a guarantee any storm at all happens anywhere. The wave could be an error. But even if it happens 100 mile shifts either way are normal errors at that range. And the strong consensus I do think increased confidence. But from like 10% to 30% or something like that. Normally I wouldn’t even give some crazy snowstorm on a day 7-10 run without a ton of guidance support any chance at all. I’d just toss it. This gave it some hope. But some were acting like it meant a big snow was the most likely outcome.

@frd if you don’t mind me asking, what part of Delaware do you live?

Since when did we start trying to lock in details on progressive waves 150 hours out? This is nuts. Some are acting like these storms are 24 hours out having an emotional reaction to every run. Just because we had a few days with guidance spitting our crazy snow totals doesn’t chance how far out it is or make the guidance more accurate at those ranges.

My reference to PD2 was specific to what that run yesterday showed. I feel like I’ve tried to encourage caution regarding this pattern. But I know that’s impossible when models are spitting out crazy clown maps. I’m also trying to balance caution with not being a deb. I don’t feel like we’re doomed. We could get a big snow. But when I searched for analogs to next week many of them the bigger snow was to our NW. but it was hard to find a great pattern match honestly. I’m just have been more skeptical I think or maybe reserved. Why? If we get a snowstorm Feb 25 you’re gonna complain it wasn’t Feb 10? Plus I’m not throwing in the towel on next week. Why is everyone going to extremes. I’m not confident we do get a big snow soliton. The more common outcome would be a parade of waves with some snow and ice with each. But anomalies happen. It wouldn’t shock me if we get a 6-10” snowstorm somehow next week from one of those waves. It kinda would shock me if those 20” storms from yesterday’s Euro and GFS hit. Dunno what they were smoking. But it also wouldn’t shock me if we get 1-3” then ice which is historically favored in that pattern. But it’s too early to be confident on either outcome.

I think we get at least some snow before and a week ago that would have been a win. But I still like later in Feb or early March even more.

I wasn’t going to post it. But unfortunately if the reality ends up that, that’s what this type of pattern actually historically tends to produce. Our big snow patterns usually have a negative at h5 centered further south.

Before we get another emotional reaction from the same people, this is just a general observation not specific to our snow threats just pointing something out... Now with the disclaimer out of the way... it is a little odd that with that extreme a -AO with a TPV displaced over Quebec that the heights are as high as they are over the the CONUS. Basically...you would think it would be colder given that longwave pattern. Again...I am not saying we won't get snow... there is way more that goes into that then the mean h5 heights.

Honest question, I am not as familiar with how the NHS does things at these type ranges...what does their projections look like on a tropical system 150 hours out? How does it compare to what the NWS tries to do regarding a forecast of a synoptic mid latitude system at that range? Are these two comparable enough to usefully utilize what NHS does to this type of situation?

Yesterday we got a couple Op runs that showed a consolidated storm idea, but that was never the most likely outcome in this type patter, and was probably just a fluke that both major operations spit out the same permutation at the same time. There are more likely to be multiple waves along the boundary. The good news is it would take a lot of bad luck to miss all of them. It would also take a lot of good luck to get the multiple hits it would take to rack up some of the crazy numbers a few runs have shown. This GFS run was the worse case scenario where we got 2 waves go just south of us and 1 wave go just north of us. But what are the odds each wave does exactly that from this range...about 0!

Yea I know but. Chuck is very linear in some things, it’s his way, and I don’t feel like arguing semantics. But years ago when I did a case study of mid Atlantic snows I noticed the disconnect between the numeric nao and what we effectively call a nao. So I actually looked at each storm at h5 to classify the nao and there were quite a few that had what we consider a -nao but not numerically. BTW we should keep that in mind when looking at charts that show snow by numerical index. We get plenty of small snows but the numbers for a 6”+ snow for DC and Baltimore are even worse if you use the actual pattern to determine nao state v the numeric. Many of those anomaly +nao snowstorms were actually a -nao lol.

what we call it is semantics but the issue with what Chuck did there is by using a technicality to define that as a +nao then looking up all +nao -epo scenarios you’re probably getting mostly “true” +nao scenarios where this isn’t a “north based -nao block” over the top of Chucks “south based +nao”. again not interested in a debate about what we should call things. All that said Chuck isn’t wrong that this setup is flawed for a MECS level snow. The mid latitude longwave configuration is not ideal for a big snowstorm south of 40. The trough our west is an issue. But we have some things working for us we don’t have in every similar setup that gives us a shot. But the analogs to this pattern are more snowy to our north. That’s why I’ve been hesitant to get too excited. @Ji a 3-6” snow to ice should be a huge win. Look at the h5. It doesn’t matter what the models show on clown maps at 170 hours. You’re better than that, even though you like to come in here and pretend you’re not to vent your frustrations. But you know damn well that this pattern is not typical of a 20” snowstorm. Im not saying there’s not a chance at a big snow here. We have some things working for us that are atypical and could argue a better outcome than usual in the general pattern. But it’s risky to assume a big snowstorm solution from a pattern that’s atypical of that level event. Yes it’s unusual for the ensembles to be this consistent and show these totals. And yes the last time was 2016 but that storm was totally supported by the pattern. I’m more cautious here and would take a more modest snow event as a win.

Anyone know where CPC moved their analogs. The site I’ve used hadn’t updated since December.

Life must be difficult for you

If I had to choose epo or AO/NAO I’ll take the latter. EPO is more correlated to cold but the AO and NAO is more correlated to snow. Especially later Feb into March. Frankly maybe trying a wetter pattern with blocking is the way to go. If the epo ao nao all go negative again it might just be a repeat of January. Cold but mostly dry. This would be warmer but way more active but with a suppressed storm track.

I’m not disagreeing but just opining how we kinda set ourselves up emotionally for the fall. And I do this too, this is a self reflection also. But 10 days ago when February looked like a torch we were talking about could we eek out anymore snow this winter. Now we’re gonna act like a run with a 3-6” snowstorm is blah. Given our snow climo any run that shows accumulating snow is a win lol. But I totally get it. BTW…I finally had a chance to dig into the crazy GEFS run. The 10” mean day 10 is actually from two waves. The one the op dropped a MECS from and another right after. That follow up wave is low key gaining support on guidance just hasn’t shown up big on any op runs yet. But it’s worth noting that big mean isn’t all from the one storm which does kinda temper things “some”. The op runs of the euro and gfs were kinda the max potential solutions. It’s good that the ops show that but it might not be the most likely outcome yet. I don’t want people to get themselves to a place where if we end up with a 5” snow they’re acting like it’s a fail.

It’s not typical at any range

10 day mean

GEFS went nuclear 4 day mean

Still the 12z AI would be the nightmare lol scenario for those in the same snow hole that’s been the last 8 years. 3 waves go north and one south leaving a comical snow hole over guess where! I think it should at least be a cautionary tale that nothing is in the bag yet.

Something’s been missing

lol you’re north of the extreme mid level firehose Im talking about on this run too. But I’d be suspect of those crazy totals down in central VA as there’s very likely a mid level warm layer associated with the strong SW h7 winds partially responsible for that crazy precip band. The gfs won’t see it at this range. Remember places in central VA expected 18” before PD2 and got 8” of sleet instead.

The setup has some similarities.

You want it exactly where it is right now. BTW similar to PD2 there will be a warm layer above 850 that intrudes into that firehose to our south. Being a little NW of that is not a bad place to be. Not that ending up with 20” of snow and sleet would be bad either. But some of those places showing 25” will probably in reality mix more from a mid level warm layer the gfs won’t see.

Maybe in Vermont