psuhoffman

It can still change but we’re probably about 24 more hours of this trend continuing from me putting the MLK weekend threat into the “highly unlikely moving on” category. The trend we don’t like has actually been happening steadily for like 3 days. This was the look I really liked 3 days ago. Look at the spacing between the trough digging into the central US and the through over the Atlantic. Also note the hints at a weak low over the Canadien maritime. Just enough to prevent cutting but not suppressive. Plenty of room for that to amplify but the axis of the whole pinwheel around the PV is far enough east I wasn’t too worried about a cutter. Plus note there is stj energy phased up with the trough. That was a really good look. But look at the latest run. Everything went the wrong way. The stj got left behind. The Atlantic trough trended slower and the one digging into the US faster. There is no space to amplify now. Look at the flow over New England now v what was advertised 3 days ago. They are all subtle typical errors for that range but they all went the opposite way of how we wanted. If this spacing issue continues to degrade I don’t think we’re that far from this being in the very unlikely category. Tomorrow it will be inside 100 hours. Huge longwave errors start to become less likely after that imo. I’d like to see improvement by 12z tomorrow.

18z eps is a pretty big step in the wrong direction. Both the ocean storm and tpv lobe trended west and more amplified which creates an even more suppressive flow. This one is bleeding the wrong way right now that’s for sure. Ggem looks best but it had a cutter 24 hours ago. Everything’s trending towards less spacing.

Yes but not past 12 hours yet

The euro op doesn’t go out far enough. The SW is just entering ND when the run ends. The 18z is slower with both the ocean system and the NS SW over New England but also the SW diving in from western Canada so that’s a wash. I can’t say how it would shake out but I dont see anything that screams to me better or worse than 12z.

How about the headline “EPS thinks DC has above normal snow by Feb 10!”

Which probably means 2nd week The euro has been trying to revert to a canonical Nina pacific week 3 all winter. Same way it was doing that with the Nino in 2019. I’m sure eventually it will be 2 weeks ago the euro was saying by now we would already be back into an awful pattern.

A man enters the confessional of the priest of the snow gods. The priest begins with his typical blessing, “may the flakes be forever in your favor, what are your sons my son”. The man admits to having brought up December 2000. The priest tells him “say 3 blessings of the NAO and take one drink of the holy water and you will be forgiven. The next man enters the confessional. The priest repeats his blessing and asks what his sins are. The man admits to bringing up March 2001. The priest says “say 5 PNA creeds and take 2 drinks of holy water on your way out and you will be forgiven. A third man enters and after the blessing confesses that he brought up both Boxing Day and March 2013. The priest cringes but says “my son say 10 blessings of thy Devine arctic oscillation and take 3 drinks of holy water on the way out and you will be forgiven. Lastly a fourth man enters the confessional and after the blessing just grins at the priest and remains silent. The priest says “well my son, what are your sins”. And the man grins some more and says “oh I just peed in the holy water”.

3 weeks of a great pattern and your headline is “pattern relaxes” 4 weeks from now! You’re becoming too predictable

I definitely do remember that one and that stretch. And there was a time when guidance was too far south with NS SWs more often then not. It wasn’t 100% though. A couple weeks after the storm you’re referencing there was a NS wave that teased us a week out then got suppressed. Everyone was too busy celebrating a 3-5” snow that fringed me to worry about it. The last 5 years though it seems things are just as likely to go south as north. I can think of 2 similar setups in recent years that ended up suppressed. I think it just seems stuff goes north because we do miss way more storms to the north simply because we’re pretty far south for snow so there is always more chance of the boundary being north of us than south. In this case it’s all about the spacing. If that amplifying wave to our northeast moves out quicker or is weaker or if the system diving in slows down to increase spacing it will trend north. If the spacing gets worse it will stay south. ETA: but I definitely think it’s still true that you cannot trust guidance on where to place a NS feature at longer leads. South or north the SW is unlikely to be exactly where they think right now.

12z ensembles snow means for those emotionally affected by such things. geps Gefs eps

EPS day 15… big picture so long as these 3 features in the pac keep reloading we will have a favorable pattern. No sign of it breaking down through day 15.

There was one week (granted it was the worst timing over Xmas) that was awful and a 60 degree rain wiped their snow out. But before that snowshoe and timberline were actually having an average typical December. Both had about 50% of their terrain open which is normal for Xmas. And both have already recovered back to 50% and will be well above that soon given the pattern. WV resorts are less dependent on natural snow and have snowmaking capability on 100% of the mtn. The northern New England resorts that avg 250-325”rely much more on natural snow. Additionally the pattern coming up might be better for WV than Stowe wrt natural snow. So you aren’t wrong that WV had a rough Xmas break period as well but I think all things considered they are lined up to have a better Jan compared to normal than northern New Eng might.

Excellent eps run. I’d rather look at the whole window rather than a discreet event in a complicated flow at this range. 7 day temps 7 day mean qpf That looks pretty good to me. Pattern continues after this as well.

EPS REALLY likes that threat around the 20th. That’s the one the Gfs turned into the BECS the other day.

It could be a lot worse. Northern New England has had very little snow at all and the ski resorts up there depend on it and the coming pattern isn’t even necessarily good for them. Very likely significant snow is suppressed south of them as it often is mid winter except they should have put down a 3 foot base by now. Looks like another weekend coming up where WV is the better option than northern Vermont!

You were dismissing the day 10 threat on the op euro but that’s the wave the Gfs turned into the 40” storm Saturday and that is the threat with the best setup as it looks right now. People are just impatient. The best part of this pattern is that it isn’t one and done. It looks like a sustained long period of chances for something to amplify just right. We need that because our success rate is pretty low on any given discreet threat even in a good pattern. Every once in a while we get lucky like 2010 or 2014 and almost every possible storm hits. But other then those once a decade periods we usually need multiple threats in a good pattern to get a good storm. Think of the “good” patterns we’ve had since 2014. We wasted several threats in 2015 before that arctic front set off our run the second half of Feb but we had to watch New England get 80” before our run started! We wasted a few SWs in Jan 2016 before the storm. We wasted 3 in March 2018 before we got a storm. Last year was weird in that the longwave “pattern” was good but there was no cold available due to what happened in late December. But even had there been cold we wasted like 4 discreet threats before something finally amplified enough to cause a storm. Wasting threats is normal. It often takes 3-4 good discreet threats to get one actual snowstorm.

A couple days ago the op Gfs and euro took turns showing snow and everyone was whining the ensembles were meh with a low snow mean. Now the gefs and geps were the weeniest runs we’ve had in a LONG time and everyone’s whining about the op euro run.

Except that if you removed it completely the weekend threat likely cuts and we’re waiting until the early next week threat anyways! The setup is like a big pinwheel (not talking about the ocean storm I’m talking about the whole longwave pattern rotating SWs around the PV lobe in Canada. The “suppression” behind each wave in that cycle sets us up for the next. Even with a great pattern there isn’t some cut off Rex block to prevent a cutter. There is ridging in the HL but not a true block. That’s the one time we don’t have to worry about wave spacing. Otherwise even with a favorable longwave pattern too much spacing and something that amplifies a lot will likely cut. Im not saying that to say this pattern isn’t as good as a true blocking one. Sometimes we fail then too. Not enough stj and those can be frustratingly dry with NS miller b storms teasing and frustrating us. And we have gone on some epic tears in this kind of pattern before. Jan 1996 was actually a similar setup that worked. Not exactly but close. This was the pattern Jan 1-5 that set that in motion. Notice the un Nina like north pac trough similar to now with the epo/pna ridge. Note though there is no canonical Rex NAO block like 2010. There was a beautiful block in December and we got some minor snows from it but by January we just had some ridging up top and a favorable longwave pattern driven by the pac. We got lucky with spacing though. A weak wave came through a few days before the blizzard which prevented it from cutting then the clippers was right after it and that helped us with the storm 3 days later! That epic week was due to lucky wave spacing rotating around in the longwave pattern.

The pacific is a lot more favorable now v that setup but the Atlantic might be even more suppressive. In the end it might end up a wash creating a similar result I’m just pointing out the differences.

It's way more moving parts than just that ocean storm you hate. It's also going to depend on spacing with the NS and which STJ waves can time up with one of the NS vorts and how much and when something amplifies. I can sum up what we're looking at for the next 10 days. And the good pattern by no means ends there...there are "threats" stacked up in the flow one after another after that on the long range guidance, but I think 10 days out is the furthest we can realistically even guess as the general synoptic setups. The rest of this work week were stuck in the NW flow on the backside of the trough and there is no chance for anything of significance. After that the trough starts to retrograde in response to the north pacific vortex backing off. The pac jet retraction we have been hearing about. After that there are 4 NS and 3 STJ SW's in the flow to be watched. Each likely has more room to amplify than the last. The first NS and STJ SW become the ocean hurricane you hate so much and that has virtually no chance to impact our area. It's coming too soon in the process. The second NS vort is the one that could impact our area over the weekend. It's digging impressively far south for a NS system, it's leaving the next STJ wave behind and going it alone. The limiting factor with that threat is that it is almost 100% NS and the ocean hurricane you love might be too close limiting its ability to turn the corner and amplify. It's far enough out though that it has a decent chance and is close enough to something on guidance that I wouldn't be shocked, but suppressed is probably the threat to missing that. The next threat to watch is around next Tuesday Jan 18th with NS wave 2 and STJ wave 1. But we have no idea how they interact and if the STJ wave phases or gets left behind again. All the events before then will impact that threat window. Still...the general longwave setup heading into that period is even better and this one will have a STJ wave around to be tapped if things come together. Just at a glance this might be an even better threat than the weekend...with the exception of if the weekend thing blows up it could suppress the next. There isn't a lot of spacing between these SW's. The last threat window I will even speculate on would be later next week around the 20th as another NS SW and STJ wave come east into the trough. Again...the trough axis and spacing on this one looks good from this range but the details will be determined by what happens with threats 1-2 which are partially impacted by that ocean storm. There look to be more threats lined up after but now were getting out to total fantasy time ranges. There is way too much going on in the flow to expect guidance to get any of this right from outside like 4 days or so. This pattern is absolutely loaded though. The only way I see a total fail from this would be if the spacing ends up too close between all these waves, and none really amplify and they all split the difference and we get a bunch of weak waves. But guidance has a hard time resolving exactly what SW to amplify in this type of pattern from range. I wouldn't worry about that yet.

Math is hard

Ok so you’ve identified the problem, next step is what to do about it.

It is BS but Chuck had one good nugget mixed into his typical word salad this morning which was it’s not that cold given the pattern. The frame he pointed out had a 1040 high in southern Quebec/Ontario with a NW flow and storm off the coast and it was only “average” temps here. I can pick out several days where the “pattern” says it should be a truly bitter cold day but it’s like 40 in DC. That’s not necessarily 100% relevant to any discreet snow chances since a 40 degree surface temp on a sunny day isn’t relevant to what it would be while precipitating when the dew point is like 12* but it’s still worth mentioning, as @WxUSAF has also noticed, how hard it is to get REALLY cold around here lately.

Suppressd That’s a legitimate possibility but it’s inherent risk anytime we are in a good pattern with big storm risk. We need tha risk of suppression because that is what also gives us the possibility of a big storm. Without a suppressive flow to resist strong WAA and ridging any amplifying string wave will cut to our north. Of course the risk then becomes any wave not amplified enough will get squashed to our south.

Gefs took a baby step towards the euro.