psuhoffman

PS: I just feel like the micro excuses are wearing out at this point. Its been a string of overly specific reasons/excuses why a pretty good synoptic setup failed. "December climo sucks", the pacific was bad, no HL blocking, the WAR...but what they all have in common is no cold air. And frankly we've failed with exact opposite pacific patterns recently so I am tired of the "its the pacific" excuse. The pacific is always going to be there upstream of us so if we can't snow because the pacific is too warm thats never going away.

I had wanted to try to avoid this general topic completely but its become obvious that is impossible...but I will keep my part of this discussion to this thread so as not to annoy those that would rather not think about this in the main thread. @Terpeast I see this as all related. A lot of this is just conjecture at this time simply because we don't yet have a long enough period of data to prove with statistical significance but some very bright minds along with well designed simulations have theorized that there is a causality between AGW and several of these chronic pacific issues we have been having for a majority of our winter seasons recently from the expansion of the Hadley Cell to some of the persistent SST issues in the tropical Indian and Pacific, to the prevalence of a la nina base state. Then, add in that on top of the longwave pattern issues created by these problems in the Pac, regardless of that at any given moment in time warm anomalies over the NH land masses are outnumbering cold about 70-30. So even without those issues simply by pure chance our odds of having cold over us are going to be more difficult. And lastly...there is conjecture that the SST changes also related to warming in the Atlantic are partly aiding the prevalence of the WAR (which is also a feedback issue from the pac longwave pattern as well!) and why its been difficult to get or sustain a 50/50 feature. Basically, there are a lot of interrelated factors caused by warming, but every single one of them seems to be the opposite of what we would want. The only factor related to warming that could work in our favor is the increase in precipitation patterns during the cold season in general. And I do think we have seen evidence of this in the rare cases where we get a cold season but that benefit only matters when its cold which is becoming increasingly rare. @CAPE and @WxUSAF both of your analysis of the issues regarding the specific details we need (50/50 or perfect phasing) are 100% accurate. My point is just, at some point it feels hopeless if we need some super anomalous string of events to go exactly perfectly to get snow as if we are living in coastal SC or something. My point the last few days when I voiced my concern with this setup has been the snow solutions seemed to be relying on something I don't see as very likely and even if it did happen is certainly not something we can expect to become a reliable repetitive way to get snow. Needing some mid latitude system to phase and bomb into a super cyclone and lead to the inception of a TPV in exactly the perfect location at exactly the perfect time is not the way I want to have to roll here. Yes a 50/50 is a feature in just about every one of our 20" snowstorms. Because to get a storm that big in the DC/Balt area we need some pretty major resistance to the WAA necessary. We are too far south to be obliterated by a CCB like NYC north...the only way we get a HECS here is if a majority of that snow comes from a strong WAA feed ahead of the wave and for that to stay all snow and produce prolific totals we need a 50/50. But I am not lamenting that this isn't going to be a 20" storm. What happened to getting a 6" snow from a messy storm where the mountains and get 20" from a setup like this. When I examined every 4"+ snow at BWI years ago that made up a lot of our events. Frankly very very very few of our storms were because we lucked into the absolutely perfect conditions, and when that happened thats when we got those 20" storms. But most of the snow events were messy. What happened to getting 3" at DCA and 5" at BWI and 6" at IAD from a messy storm where we mix but the big snow is to our NW. That used to be the typical outcome of a system that tracked to our south but everything wasn't "perfect". Lately it seems we need perfect to get any snow. Basically...the storms like these below... Hi Low QPF Snowfall 36-30 1.13 4.6 37-30 .77 4.1 45-33 .86 6.9 34-31 .92 3.0 37-33 .92 3.4 39-32 .72 3.0 43-33 1.09 5.5 39-31 1.04 6.9 39-32 .67 3.4 33-30 1.63 6.4 38-33 1.03 3.3 I pulled all of these were from DCA from my past snowfall study. Look at the temps and precip...these were all obviously mix storms...and I remember the H5 from most of these it was because there was no 50/50 and a marginal "pac puke" as we call it lately, airmass to work with...but they were good tracks during mid winter and so we at least got some snow from them. And my area did great from all these storms. I think they were all 12" plus up here. But now...look at many of the permutations in the 3 ensembles. They have perfect track systems with rain to Montreal! Another good example is 1998. I bring that up because that year is showing up in current analogs a lot. And yea that year SUCKED for DC snow so its easy to say "well this happened before". But I was at Penn State that year and we got crushed with snowstorm after snowstorm all winter. Even my area here had about 20" that season because all those perfect track rainstorms in DC were a messy mix with a few inches of snow up here. Places with elevation to the NW of the cities actually got quite a bit of snow that winter. But most of the permutations of this are rain even in those places with a perfect track, and we've had several of these over the last few years. That is my bigger concern. We can't seem to get any frozen event, even a flawed mixed type, unless everything is perfect or some incredibly unlikely string of dominoes all fall exactly the right way. And lastly, yea the pac is the problem. But guess what the PAC is what is upstream from us, its HUGE, its the largest heat source on the planet, and other than the rare times when there is cross polar flow (and that isn't even really a good longwave pattern to get a system under us!) we will be dealing with an airmass that has significant influence from the PAC. The airmass this week isn't pure tropical pac puke. There is quite a mix of flow from the Yukon area mixed in with mid latitude pacific air. The problem is its torching even in the Yukon, and the mid latitude pac air is +5 to +10 also! And both of those facts don't seem to be a right now at this moment bad luck kinda of problem. They seem to be a permanent base state status quo lately. @Weather Will I am not giving up, there is still a path to get snow here. The phased bomb 50/50 scenario could come back. Or Wxusaf's scenario of a perfect phase could happen. But what is depressing to me is how difficult that is and how that is never going to be a reliable way for us to get snow. Look at the ensembles. They are very good simulations based on the current conditions. They are realistic possible permutations. And the vast majority of the permutations show a rain solution even with a perfect track and even in places to our NW. Even if we get lucky and we get some super bomb to cause a TPV to form exactly where we need it and this ends up snow...that doesn't change the fact that it was a realistic scenario that a storm could take an absolutely perfect track on what is statistically the coldest week of the year in DC, and it would be nothing but rain all the way to Canada! That is alarming in a larger 30k foot view kinda way to me. I am not focused on the specifics of this event, that is a bigger problem imo.

I don’t see much blue anywhere over any mid latitude land masses.

Perfect write up but let me summarize this…. On the coldest week of the year it’s simply too warm no matter how a storm tracks and there is no cold air within 1000 miles of us.

If we actually get a perfect track 985 low on Jan 15 and it’s rain I really am done. What’s the point.

Unfortunately I’m not sure if that path even exists because with the ridging over the top the weaker permutations among all 3 ensembles get squashed. That’s why the snow mean is pretty disappointing compared to the h5 and mslp looks, especially on the gefs and ggem ensembles. It’s basically 3 camps. A minority cutter camp. A minority weak suppressed. And the majority camp with a perfect track but a lot of rain storms among that group. Frankly almost all of them are rain on the 0z geps and gefs

That’s actually a good signal for that range. There will be spread holding down a mean from that lead. The bigger issue is way too many perfect track rainstorms among the members. Like p1 here. This is a rainstorm!

Not totally true, a SSW around then in 2018 led to an amazing pattern in March and one big snowstorm and a couple other minor snows. With some luck it could have been even better.

Just worth noting 8/10 current top pattern analogs are ninos.

Yes but it had that same spread at 12z it was just masked on the mean by that one member that dropped 40” over DC lol.

Honestly looking at the individual members this run is identical to 12z. The difference in the mean is at 12z there was one member with 30-40” directly over us. This run there are 2 crazy members like that but one misses just north and one just south and so the mean looks less impressive. But looking at the scope it’s a very similar spread and the probabilities of snow look about the same.

I don’t have time (nor do I think it’s worth it) to dig deep into it but from a quick eyeball of the individual members it doesn’t seem any are true cutters. There are 2 that amplify too soon for our purposes but still track west to east under us and bring some frozen precip to the northern parts of this forum at least, but the big snow is PA line north. Then there are a bunch of op euro looking solutions that miss just to the southeast with the best snow. The rest seem to be a camp that fails to get its act together between a northern and southern wave. The northern wave weakly slides over the top and the southern is suppressed. Some of those might be giving the impression of a cutter. But they aren’t big snows anywhere just a split system with a weak wave to our west. It has a lot of spread which is to be expected at this range.

for 60 years DC averaged 4 snowfalls a season of 1" or greater. For the past 20 years that has dropped to 2.9 and over the last 10 it has dropped to 2.4. Furthermore, its worse when you dig into that. It used to be rare to get a season with less than 3 snowfalls. For a long time 3-5 snowfalls per year was the common and anything above and below that was rare. Recently we still get the rare season with 6 or 7 snowfalls but what is happening is in the rest of the seasons suddenly getting only 1 or 2 has become common. What used to be rare, getting less than 3 snowfalls in a whole year, now is happening regularly. It was never easy to get snow. But it was easier. And I have noted recently that we seem to need increasingly anomalous events (crazy combinations of arctic air with uncommon storm tracks, ridiculous wave spacing, perfect timing) the kinds of things that just aren't ever going to be a repeatable staple to get reliable snow regularly. The most common way to get a snowfall in prior eras was simple...get a wave to slide under us and have enough cold air in place. Lately...unless we get a string of anomalous events the cold part is simply missing. My point was I would like to see us get snow in a way that is repeatable. Simple. Easy. Anything that takes a congruence of several unlikely events all going our way to get snow is unlikely to repeat very often and doesn't really give hope we have broken out of this funk we are in.

The joke is it doesn’t happen as often as I reference it and in the end over longer periods it doesn’t matter because for every fringe there are 5 storms that we get more. But…the fringe is real. I’m at the northern edge of this forum at 1100 feet. If we’re discussing a legit threat for the greater DC/Balt forum then by far the bigger risk to me getting left out is for a fringe. Odds of it shifting so north I get all rain are slim. Fringes happen here usually at least 1 a season but in a normal season they are offset by 4 storms we stay snow and south mixed. Last year was an anomaly.

On a more positive note...the GEFS went the other way, still has more phasing with the Jan 11 system which leads to an even stronger 50/50 feature 12z v previous runs...and a colder look for the threat on the 15th. So a better/colder outcome is very much still on the table. But my point is still valid... even if we do actually get the ridiculous course of events needed here to get snow...doesn't change the fact that I would like it if we didn't need crazy rare things to all happen perfectly in a convoluted domino setup for us to simply get a snowstorm. I would like to just see a freaking simple wave slide under us and have it be cold enough to snow without some crazy progression.

The track isnt the problem, the high isnt the problem. The point of a "perfect track and high" is to create the "flow" needed to get cold air or keep cold air over us during the storm. If there is simply no cold air it doesn't matter. What good is a NE flow if the air to our NE is warm also? The issue here is some past runs phased a super bomb to our NE which created a ridiculous northern fetch behind it and drilled what cold there was way up in Canada all the way down into our area in front of the storm. This run that feature wasnt there and so all we have to work with is what we usually 99% of the time will have to work with which is whatever air mass is immediately to our north...and its crap.

IMO the bigger issue here why we don't get a frozen event out of the GGEM/GFS 12z permutation is simply a lack of enough cold. YES if we want to drill down to specifics the failure of the Jan 11 system to phase into a sub 960 bomb cyclose and stall in exactly the perfect location is why it went from a cold enough to not cold enough solution this run. But take a step back for a second...if we are relying on a complicated multiple stream phase into a super bomb cyclone that stalls in exactly the perfect location to get cold enough to snow...well umm...come on man. Was that ever really something we were expecting to go down exactly like that? What happened this run is the phase didn't happen but we still ended up with enough confluence to our northeast, a 1040 high, and the correct wave spacing such that the system is forced under us. The storm tracks from St Louis to Georgia then the Outer Banks and up off the coast. The problem is there just isn't any cold air. It's raining to Canada with a low off the coast of NC! If there was even just anything close to a normal January airmass in front of this...with a 540 line like near DC v up in Quebec, this would be a frozen event at least to some degree in our area. Sure focus on the failure of a perfectly placed triple phased bomb cyclone to drive cold 1000 miles due south in front of the system if you want. But if the only way for us to get snow is through some ridiculous nonsense like that...well ya know my take. Yea I know, but I'm trying real hard not to go on and on about this and annoy everyone...but damnit crap like this isn't helping.

Some 30,000 foot thought this morning Good, the high latitude pattern (which I’m including the prevalence of a Hudson high here) is good enough we probably will continue to have hope for these random systems to cut across and if we get lucky time up with cold. It’s a long shot pattern but not completely hopeless like it would be if we had a raging positive AO like 2020. Bad, the PNA spike, if we can even call it that, is super temporary. It leads to one shot and then we go back to a very warm look. The hope that the pacific was going to quickly morph to a more favorable look is fading. I really hope we hit on one of these long shot threats the next 10 Days or it could get insufferable in here if it’s Jan 20th with no measurable snow and nothing but torch on the horizon.

He actually has proved something I speculated about before. By showing that when other factors are bad the mjo cold phases don’t really correlate to cold it confirms that the mjo cold phases really only have a lot of impact when the pattern base state is cold. When we’re in a modoki Nino with a -QBO and low solar then sure it correlates to cold lol.

OK please forgive me for the late night possibly impaired rant but I am putting aside my science hat and gonna release my inner Ji for a moment here.... I HATE THOSE GUYS...like hate hate hate Furtado with the fire of a thousand suns. He has always been right btw, but he only seems to pop up in my twitter feed or on here when its to tell us how the MJO or some other tele isn't going to actually cause cold like we expect because of some other intervening countermanding factor. He did this years ago showing how "actually in a nina and a -QBO Phase 1 is actually warm" crap and another time it was "during high solar and a strong PV Phase 8 is warm". Now its "when the PV is strong ALL THE COLD PHASES ARE WARM" WTF. And I have repeatedly asked him "then what correlates to cold during these conditions" and he has never once answered...I guess we know the truth NOTHING DOES. Again, he is always right...but its annoying that he always shows up to explain just how FOOKED we are lol. Oh and this is why I don't waste time on the MJO like some people. Look at the correlation charts...the warm phases have a super high correlation to our temps...and the cold phases have almost no significant correlation! So in other words when the MJO goes into warm phases we are definitely screwed...but when it goes into cold phases...it might not help us at all. Great. And if you really want to get depressed last year someone posted a chart that showed over the last 20 years just about NOTHING correlates to cold in the east... lol Sorry rant over, just had too.

They aren’t meant to be forecasts. They are simulations meant to be tools to make a forecast. The simulations incorporate so many variables and have to make so many assumptions where there are unknowns it’s totally logical that there are different permutations each run. Again, they aren’t a forecast, just a tool.

I agree with the skepticism, our base state has been suck, but this is overly simplistic. 1/96, 1/00, 2/06, 3/09, 1/11, 3/18 all were big storms in a Nina. We can get a snowstorm in a Nina. With the exception of 96 we just never string together multiple hits to produce a big season but one storm can and has happened quite often.

I’m ok with a suppressed solution at 200+ hours same as we used to be ok with that at 100 hours decades ago. It’s going to adjust in some ways. 50/50 chance those adjustments are towards less suppression.

I said I was "interested" and that is all that is worth saying until we get it inside about 150 hours or so. That is about the magic range where guidance has converged on the details that determine the outcome of these waves. But from this range everything is there I want to see. Its a good setup, pretty classic way we get a snowstorm really. Just have to wait. Keep in mind though, no matter how good the general setup is...even the absolute best threats are still way below a 50/50 bet at this range. This is a good look, but that just means we have a 25% chance v a 2% or 7% chance of snow during any normal period at this range. @CAPE you're 100% right about the transient nature of our 50/50's but a lot of snowstorms come from that. We actually want the 50/50 to slide out as the storm approaches. A lot of our best storms came after blocking actually broke down. There was no blocking by the time Jan 1996 and Jan 2016 happened...but the course of events was already set in motion. There was no blocking in Feb 2003 either just even more lucky timing with the 50/50. I am NOT comparing this setup to those, no one should expect a HECS here, although I do think this setup has decently high upside if it goes right BIG IF THERE, but just pointing out that a "transient" 50/50 isnt the worst thing in the world. Very few of our snowstorms actually come from absolutely perfect setups in every way just because that rarely happens. That's also why its frustrating when we keep failing with flawed but decently good setups. Yea people are right when they focus on the very specific minor flaws that caused the fail...but by the same token we should be hitting some of these. Our luck has been REALLY bad lately. The we're due index needs to kick in soon here.