psuhoffman

That rarely actually works in the grand sense. It might lead to one or two lucky hits but we are never getting a HECS or a 30”+ winter that way and those are what I root for.

Dunno man, it was a -2.5 std dv block just 3 days ago. And that is what set off the pattern change. Yea it’s slowly fading now and will be waxing and waning bit slowly dissipating overall for the next 2 weeks. But that’s normal. A block is rarely going to maintain a crazy standard deviation for that long. It is an anomaly. The heat bubble that is the block is usually going to cool and weaken over time after the wave break or SSW that creates it wanes. If we need a 3 std block to maintain itself for weeks on end to get snow…. Again this is a matter of degrees. Yea if the block was some historic anomaly it maybe could bully things more in our favor. But we’ve snowed in the past with much less. I really don’t get it. We keep failing in different ways in looks that I know from experience are historically pretty good and the only common thread is one thing…it’s too warm. But everyone else is like “no it’s cause the high was 20 Miles too far north, then the trough axis wasn’t perfect, then it’s cause there want some cross polar arctic blast, then we didn’t have some -20 stdv block”. I mean come on.

I was exaggerating but the reason there is no blue on many long range seasonal products is they can’t decide where to put the cold and because it’s outnumbered in areal coverage like 60/40 or worse all the blue gets eliminated when the smoothing happens. In reality there will be some blue somewhere. But it’s also still indicative of how the odds are increasingly stacked against us. I’m not arguing it can’t snow anymore. I know it can and will.

It is why the wave tracks under us. The block X displaced Y which causes the wave to dig instead of lift like every other pac wave. But a HL ridge can’t make the airmass under it any colder.

It doesn’t matter what longwave pattern we get when there is no cold air anywhere!!! But please tell me again how it’s the exact location of the high that’s the problem.

I wasn’t comparing this to 58. I was pointing out 58 was highly flawed with a primary near Chicago, an h5 track through PA, and no arctic air. And we got snow! Yea the high isn’t perfect. Yea the phase isn’t ideal. But a 985 low tracks just east of OC and most get no snow at all. When I examined every 4”+ snow at BWI years ago almost none were perfect. Only the crazy 1996 type storms had everything textbook right. And even some pretty damn big storms didn’t. But a flaw or two used to mean we get 3-6” instead of 12”+. So I roll my eyes when we go wave after wave with no snow at all and somehow each time it’s this one thing or that one thing. It didn’t used to be that hard to get some snow!

Actually there is kinda warm. But it’s north of the boundaries where it should be kinda cold. Lol.

No there was a true arctic airmass from an epo ridge…yes it was very warm south of the boundary before the storm started but that’s just true all the time now. There is no kimda warm. It’s a torch south of every boundary lately. And DC never got that cold because it never got far into the airmass But the reason that had such a sharp cutoff north was the dry arctic air pressing down on wave.

Kinda negative given todays 12z was the highest probability of 1” at BWI all winter. 78% using my combined formula.

The pattern is real. I never hyped wave 1. Said it’s starting too far north. But it did get suppressed to the point it secondaries to our south. But with no cold the primary starting out to our NW is no good unless it bombs. The next wave takes a pretty good track. Just not cold enough. The pattern matches our best march snows! Imo the pattern hasn’t failed. It’s exactly what we hoped. Do I expect there to be more threats with good track systems between March 17-25 yes. Do I have any confidence they end up snow? No. Frankly I’m not confident we can snow easily in any pattern that requires a N Amer domestic airmass to be cold enough. I’ve seen no evidence of it lately. Has anyone else? When was the last time a storm worked with a marginal domestic airmass with no cross polar arctic flow without it being an absolute qpf bomb like 2016? I seriously can’t remember the last time DC got like 4” of snow from some wave that tracked south of them in a typical domestic airmass. I can list dozens from the past but can’t think of any in a long long time.

@NorthArlington101 my two dates (before and after the 20th) show on eps. Threat for 18-19th Threat for 22-23 Both feature a perfect longwave configuration. West based -NAO, 50/50, trough digging to our west and SS dominant. Probably won’t be cold enough but that’s another issue unrelated to the pattern.

As expected the best snow signal for the coastal plain is centered on March 18th.

My wave 3 looks good on the euro at least.

I really don’t want to go down this path anymore, we still have hope we can do this later…but if we did get a 58 repeat today it would probably fail and people would say “but the h5 track was to our north and the primary got to Chicago and there was no epo help so the airmass was too warm” not realizing 58 overcame all that AND we use to snow in flawed setups all the time. Probably 80% of all those storms I case studied had some flaw. That’s why I go mad when we have one decent setup after another fail during our least snowy period ever and each time someone picks apart that flaw that will invariably be there in any storm as the reason it didn’t snow as if we are Atlanta and should need every single thing to be 100% perfect to snow.

But most of those big March snow analogs were from the 50's and 60's...its legitimate to wonder if those same patterns would produce the same results now.

The only way for it to work given what is now the obvious characteristics of the airmass is for what happens up off NYC to happen 150 miles further south. If the storm were to bomb off the VA capes and stall near OC it would dynamically cool the DC area enough to get some snow in the CCB. Whether that can realistically happen...its a rather large ask but not impossible given the blocking in this situation. But we need the most extreme solution to happen and we know from experience that is not where you want to be.

This is different...the fact there is snow in the vicinity...and the low isn't 300 miles NW of us...is the pattern change. The fact its too warm is NOT specific to this pattern, that has been a problem a LOT in a lot of patterns over the last 8 years or so...yes I am including 2016 because there was one absolutely perfect track rainstorm that year in Feb also...I got 8" of slop up here but it should have been a 6-10" snowstorm for everyone given the track and time of year but the boundary temps were just too warm. If this fails to produce the amount of snow we want it isn't the pattern failing...the temp fail is not specific to this pattern.

Yea...this is the GFS for Friday night now This is what it showed when it was still 7 days away...

We might just have to respectfully disagree on this one. Is the "block" the strongest block ever no. But its legit, its not just a heat bubble that originated from the mid latitudes like we've seen a lot lately. It originated from an east based block that retrograded and will slowly degrade. That's actually the best progression usually. As for the progressive nature, its not a split flow nino pattern no. But the pattern is blocky imo. Two straight waves are going to stall along the east coast and amplify and spin for 2 days before being forced east under the flow. Given how far north this first wave started without a blocked flow it would cut to Hudson Bay. Lastly... more cold added to the equation both forces everything south some AND amplifies that scenario. More cold increases the baroclinic energy and we get a more amplified solution. Short of this being a split flow nino pattern the only thing I think that is missing from making this better is colder air. If there was a colder airmass I bet you one of these waves coming up would bomb out where we need. But that is just my opinion and there is no way to prove that.

Models were way over amplified out west just a few days ago. Probably will correct again given the pattern over the top.

I like just before and after that date. The timing of the waves is coming into better clarity. There will be a wave around the 17th that I think has a chance regardless of what the op runs are showing right now. And I think there might be a wave after the 20th but we are getting really late by then. I am not overly influenced by op runs beyond 150 hours.

Again rare combo... poleward EPO ridge in combination with a PNA ridge and a displaced TPV. But even with all that...it was not a snowy winter. Look at a snowfall anomaly map for last winter, it was below avg snowfall over 75% of the east and mid atlantic. A few locations got lucky with some of the progressive waves but the majority had a below avg snowfall year. And yea the pattern only lasted one month but part of that is because its a rare pattern, and part is our snow comes in chunks...sometimes one month has to be it and be epic and get it done. But that pattern while better than this winter of course...is not usually how we are going to get a big snow season. Its a rare combo AND its not even usually a good way to get systems to amplify along the east coast. Basically we got about as lucky as we ever will in that type pattern and it still was only good enough to give us a below avg snowfall year in most places.

I don't think we disagree here just focusing on different things. My point was there are quite a few members in the mean that do get the qpf up around .5 qpf and those are still rain also!

The loading pattern for Feb 2003 was a poleward EPO ridge COMBINED with a severely displaced monster TPV over top of us that in conjunction displaced true arctic air south. The specifics that lead to the storm was as the TPV started to exit it traversed the 50/50 region which set up possibly one of the most MONSTER 50/50's in history which compensated for what was honestly a complete crap longwave pattern otherwise. If you look at that storm its an anomaly in almost every way except it had the best 50/50 of every HECS which overcame the problems everywhere else. But those kinds of things are an extreme anomaly. Yes they will still happen. Every once in a while we will get something like that and it would still work. A year like 2014 would still work where we got an absolutely perfectly placed full latitude epo/pna ridge combined with enough of a -AO at times to displace the boundary eastward of normal in that pattern. Or Feb/March 2015 where we got a -EPO in combination with a displaced TPV in eastern Canada. Things like that will still work. And eventually we will get lucky. But those kinds of patterns have always been extremely rare and are not going to become more common just because all the other ways we snow no longer work as well. The issue I am talking about is why we can't get much snow in every other pattern that doesn't involve cross polar flow and some ridiculous anomalously displaced TPV scenario. That is never going to be a reliable common way to get snow here. That is super rare. I am not so much talking about our super huge snowfall years being affected. WHat I think is being affected more are what used to be the more common years. A year that used to be 18" is 9" now. A season that would have been 15" is 5". Stuff like that. Marginal events where we could have got a 5" wet snow storm from a less than perfect setup in a marginal airmass no longer works. And that used to be a LOT of our snow. especially in those less than perfect seasons which make up 90% of our seasons. It's also possible we lose some snow in the big years on the margins...but there would be no way to prove it and most wouldnt care that it was 43" instead of 48" in a season. But it really makes these years in between those rare perfect pattern season just god awful instead of bearable.

That plot in isolation is a bit misleading because a few of those members have a slower evolution and are going to show precip in later panels. Some precip falls in the next panel on most members...if you look at the total precip from the members and subtract what falls from wave 1, quite a few end up getting the qpf up to like .5-.6 in the DC/Balt area and those are still rain also. Yes if the storm was an absolute bomb with over 1" qpf over 12 hours it would work...but aren't we setting a high bar now? This is a matter of degrees. Of course it can still snow. In rare instances where we get cross polar flow and lucky with the track of a boundary wave...we have gotten snow as recently as last winter. And I am sure if we ever do get an absolute monster bomb storm with a perfect track in a blocking regime like 2016 or 1996 we can still get snow that way... but the problem is we are losing all the more marginal storms in a blocking regime lately. And those made up a huge portion of our snowfall historically. This reminds me of that storm in Feb 2021 where it took a perfect track and put down like .45 qpf along 95 and was just white rain and everyone said the problem was that the precip wasnt heavier. Yea that is one way to look at it...that had it been extremely heavy precip it could have cooled things another 3 degrees and accumulated....but my POV was that should have been a 3-5" snowstorm for Baltimore. There was absolutely no excuse that in early Feb with a perfect track storm, and a typical domestic airmass in place that it shouldn't have been snow. I guess that is just a matter of perspective.