psuhoffman

This is not normal for a nina. You can spin the numbers any way you want, but all 3 major airports in our region have yet to record any snowfall and that is the latest into ANY NINA they have gone without snow. Whenever something has NEVER HAPPENED BEFORE it is not normal. This is a mean h5 for all Nina's over the last 30 years. There is no clear signal that the SER is any more pronounced than other years. Actually this is the composite for all enso neutral winters in the last 30 years...the SER is much more pronounced here. This is no evidence to support a claim that what is going on this year can be attributed to simply a typical nina response. As for your comments regarding variance, yes there have been snow droughts, none have been this bad over this large an area in recorded history. I said RECORDED...we have no way to know what happened before records, speculating is silly, and its irrelevant anyways. Even if we had records that go back 500 years no one would be basing our expectations on 500 years ago. We would be basing our expectations on a more recent baseline. This is human nature. No one bases their life expectancy on the way it was 500 years ago. We expect electricity even though 99% of human history there was none. We expect to live into our old age even though over the longer term human life span was only 35 years. What it may or may not have done 500 years ago in a different climate period is irrelevant because we wouldn't be basing our expectations on that. Additionally, lets say the climate was warmer 500 years ago...and it has been colder and all our expectations and normals and pattern recognition is based on that colder period...if it is now warming back to some past climate that changes nothing. The fact remains it is getting warmer and changing out outcomes compared to 20 or 50 years ago... The only reason it would even be relevant would be to a discussion of AGW and how much of it is attributed to human activity. But we have a whole thread for that where people that want to live with their head up the ass can have at it. That is not the conversation anyone is having here. Here we were simply discussing what impact the warming RIGHT NOW is having on our snow prospects RIGHT NOW. But you seem to be trying to make the case that this is just normal variance. Sure, what is acceptable variance is subjective I guess...so if you consider the absolute least snowy period of the last 150 years to be "normal variance" then sure. I do not. But that is our opinions. The facts are it is getting warmer, our snowfall has been trending down for the last 100 years along with the warming, and now we are in the worst snow drought in recorded history (your lucky geographic location last winter aside) across the vast majority of this region.

I’m so glad you two found each other…

Agree. I guess at this point I’m not hunting a 3” event, I’m looking for a pattern that can deliver a legit winters period. I’m not saying trying to even get close to avg that’s a lost cause, but the only thing that could even change my perception at all would be either a MECS event or a legit 10 day snowy period with like 15” over several events.

I’m more interested with the look at the end of the eps honestly. It’s not far from a look that could progress to an actual good pattern pretty quickly from there.

It’s closer to 9% according to ensembles.

So would I but…

Oh you think you got jokes now

We are too far south to just rely on cold. We need a mechanism for the cold to resist a southerly flow and the boundary trying to press back north where it actually belongs. Any wave will try to lift the thermal boundary. In this case the fact it’s cold at the surface won’t overcome the fact we’re ridging out at the mid levels which drive the storm track unless we get either extremely lucky with a wave that’s too weak to push north but just strong enough to clip us with some precip…wave 1 scenario on the euro, or get that high to time up dead perfectly so the storm literally slams into it like the 0z. Even in this setup we need a lot of help. It’s not actually a great longwave setup got a big snow here. It’s not impossible. We could get lucky. But it’s flawed.

This run shows how small the margin for error is. The high is 12 hours faster and so we change to rain this run even though the wave is actually weaker initially. That high has to be timed exactly perfect or it won’t work. There is nothing in the flow that will stop a cutter once the high starts to exit.

The euro at 0z had the only way we get a big snow. Exact perfect timing between an amplified wave and a high. Look how they literally collide at the same time. That’s the only way to get a big snow from this setup. The 0z op euro showed its within the realm of possibilities but the full scope of guidance suggests it’s a low probability solution.

That's the wave I think has a decent chance to at least bring something to our area.

and you have no snow on January 26...what do you want?

Well yes won by 14-1 so here it is... but I will do everyone a solid. I am going to start with the positives and if you would rather stop reading there and sleep well tonight you can. I will warn you before I get into the negatives. Positives: For the first time since December there will be cold air around, that at least makes a good result possible. Everything else we've been tracking for a month just had no chance, it was DOA with nothing but +10 thermals all around. Even the last perfect track storm could barely manage some snow in the coldest highest NW fringes of this sub. And that was with EVERYTHING going perfectly right lol. This time if we get a perfect track it will snow. This is also how we have managed to get most of our snow over the last 7 years or so, with these progressive boundary waves, so there is precedence for this. I think we have 2 opportunities. The first is the wave as the cold is pressing. This has limited upside potential but I think it is actually the more likely to drop some snow somewhere in our region. The second threat would be with whatever energy gets left behind forming a wave that attacks the cold after the TPV slides by. This has higher upside but a lower probability. Together these 2 waves are likely our best chance at snow so far this winter. The negatives: Unfortunately the first wave is likely to be relatively weak, very progressive, and might have temperature issues. But the reason I actually think that is the bigger threat is the second wave has an even bigger problem. We are kind of stuck between a rock and a hard place with this setup. The reason the snow probabilities for 3" are only around 10-20" across our area despite what looks like fairly favorable precip/temp plots are the details. A good looking plot like that means nothing if it got there by 1/2 the members with a warm wet solution and 1/2 with a cold dry one. And that is what we have here. I know it's tempting to see some runs south and some runs cutting and thing...that puts us in a good place in between, but unfortunately the reason the vast majority of runs are one or the other with very few in between is because the in between solution is the least likely. Once again there seems to be 2 big problems, very little interaction between the streams and no mechanism for the cold to resist if a wave starts to amplify, other then for the short period where the TPV is directly overhead compressing the flow. The problem with that setup is...if the TPV is directly overhead compressing it will suppress the wave. But even in that scenario look at those runs...its not like there is some big area of snow to our south on most runs...there is actually almost no frozen precip on the northern edge of the storm on the southern solution members. Again, no interaction between the cold and moisture. IF the wave comes by before the TPV has exited and the flow relaxes it will simply slide south of us. If it waits until the flow relaxes and phases it will cut. There is a very very narrow timing window for the in between solution. There are barely any members on the EPS/GEFS/GEPS with that in between solution for a reason. The analogs to the day 8 ensembles are mostly bad results. There are a few dates we got a mixed event in our area from a wave that had significant snow to our north. There are no big hits in the analog set. This isn't a good look for a big snowstorm here. What I would want to see to feel more optimistic in future runs would be for there to be a healthy snowfall depiction on the north side of these waves at or south of our latitude, regardless of the exact track. I don't care if it misses south...but if it does miss south I want to see some big snow dump in NC not some wave that is mostly rain everywhere. What good does it do us if that trends north...because the thermals will trend north with it and we just get rain. I want to see some evidence that the STJ wave and the cold will have more interaction without phasing, because we won't survive a phase in this setup. With out that there is very little path to a win here.

just off the top of my head PD2 was north for a few runs around day 5. Then it went south then back north but not as far. I remember about a week out worrying about rain at Penn State. Late Feb 2007 there was a wave supposed to go through PA and ended up a DC area bullseye with 3-6”. March 2014 there were 2 storms that ended up south from where they were 4-5 days out The Feb 2015 4-8” to ice storm trended south A wave in Feb 2018 trended south from 4 days out Dec 2018 ugh even ended up missing most of us south after looking great 5 days out Even the storm last weekend trended southeast after looking like a cutter into a perfect track coastal it just didn’t matter, gave me 1.7” so celebration lol But your point is valid in that it’s more common the other way. I’d guess 75/25 But it can happen. I think the reason we don’t think about those as much is more often a south trend ends up a hit here so we don’t care about the bust. That’s simple geography. There is only so far south any mid lat amplified wave of significant can end up. We’re way closer to the southern envelope of possible tracks than the north. So a north trend is way more likely to screw us than a south one.

So...I've seen the overnight and morning guidance, I've looked at the points being made on both sides...and I've seen the data and indicators that I think are actually important here... who want's my honest assessment of the current threat window and who would rather just not know. I'll put it to a vote.... Hearts=YES Weenies=No ETA: voting closes at 1pm

@Terpeast just from an eyeball glance at an ACE yearly chart...the 60's were a little high overall but not enough to think that was the main cause here...they were no higher than the 50's and that decade stunk and they were lower than the last 20 years which have stunk by comparison. Obviously an eyeball glance isn't good enough, but I don't see anything eye opening there. What is eye opening is just looking at -PNA periods, we did manage to snow quite frequently with a -PNA during the last PDO cycle but its actually been trending the wrong way in that regards for quite a while...since the 1980s our snowfall during -PNA periods has been going down pretty drastically, its just been covered up because we have been in a +PNA dominant cycle so it wasn't that big of a deal.

I will try to look into ACE but my eyes are done after compiling all the NAO/PNA data for the last post. But I am very interested in the ACE theory and there could be something there. As for the enso...everyone is kinda assuming, or maybe just praying, that a nino will solve all this...but I am less sure because a lot of the nino's during the last -PDO still featured a predominant -PNA, but they also, as is true of most nino's still, featured more blocking which helped to mitigate the PNA. However, if lately blocking has not been doing that...what good would the nino do us? If we got the added pacific warmth but without suppressing the SER or PNA it might just make things worse. If that is even possible.

@Terpeast @WxUSAF @CAPE So I went through and tried to identify blocking periods that coincided with a hostile pacific and see what the trend is in snowfall at BWI. It wasn't easy, at first I tried to use pure monthly data but realized quickly, since I know what a lot of these snowy periods h5 looked like from that snowfall study I did years ago, that the monthly indexes were missing things. A 10 day -NAO can be hidden by a positive the other 20 days for instance. So I started breaking down months by 15 day chunks using the h5 composites to identify months that had a -NAO -PNA at some point then looked at snowfall. I know that gets messy and subjective but I couldn't find a simple better way. But the trends are pretty obvious. This is the scatter plot of BWI snowfall during -NAO/PNA months since 1950 with a moving average imposed. We have had some low periods before, its not unprecedented to get a short period where a -NAO is muted and doesn't result in prolific snowfall...but its suspicious we are in the longest such streak since 1950 right now. We are in the longest streak without a -NAO/PNA producing 7", 10" or 12" at BWI. Historically we averaged about 8" during a -NAO/PNA month from 1950 to 2000 but are only averaging about 3.5" during such periods since. Our failure to take advantage of a -NAO during a -PNA is a huge problem lately. The biggest problem is what has happened to December...there the trend is even more alarming This is the scatter plot with moving average for Dec -NAO/PNA periods since 1950 at BWI For whatever reason in the last 15 years or so the -NAO has lost its impact in December. We have gone from averaging about 7" from a Dec -NAO/PNA to less than 2" and the last 2 were 0. I know some say "December just isn't a snowy month" but that wasn't always true, and a -NAO december used to be snowy and now it isn't and that does account for a big part of this difference. When we only get 4 months that can realistically deliver snow we can't afford to just toss one and expect it not to take a huge bit out of our snow climo. But December does not account for the whole difference, the trend is down in other months also, just not as extreme as December...but January and February are not produce as significant snow results during a -NAO/PNA lately either. Luckily a -NAO+PNA has still be producing epic results however...if we are entering a -PDO where a -PNA will dominate the next 30-40 years this trend is ominous because during the last -PDO our snowfall during +NAO periods was atrocious. If the -NAO fails to deliver the way it did from 1945-1980 anymore...well the possible results would be catastrophic for our snowfall prospects.

no but that is an interesting theory and worth researching. I might try to get to that at some point.

the SER has a bit of a higher tendency to persist in a nina but that is not true of all Nina's so it's hard to say really. This year has kind of been a mix of patterns but the worst parts of each.

It's unheard of for a nina, the people saying "this is just a nina" are just plain flat wrong. Nina's have less variance than other winters. They are very rarely big snowfall years, but they are also rarely really awful ones either. This is unprecedentedly bad for a nina.

I ended up with slightly above 50% of average. But my main point is, and reason for my pessimism, that these patterns that have lead to some snow over the last 7 years, mainly progressive wave epo driven, are never going to lead to a sustainable truly snowy period. They just aren’t. They are patterns that are correlated to some snow but mostly fail. The issue is what’s supposed to be a good snowfall pattern, blocking, isn’t working lately. That’s a huge problem because that’s the only way historically we’ve sustained a ton of snow in a -pdo regime. Just because a -NAO has failed to work the last 4 times doesn’t mean these -epo patterns are going to be more successful. Yea once in a while we might luck into a wave this way. But unless we get blocking to resume it’s historical effect of neutralizing a -pdo and suppressing the SER, we will continue to be in a snow drought with only temporary sporadic waves to provide minor relief. I’m not hunting a single 4” snow. I’m trying to find a way out of this larger scale god awful cycle and into a snowier period on a larger scale. We are never getting there praying to get lucky with progressive waves in a -epo +NAO pattern.

The top analog is 1994. But remember that was mostly frustrating down here. We didn’t get that much snow that winter. It was below avg here! The snow was mostly north of us. And…that pattern persisted all winter. This looks like a 5 day window. So we’re talking 1-2 waves. How much snow did DC get from any 5 day period in 1994? Not much. So I could definitely see one of the waves early Feb acting like the plethora of 94 waves did but that would mean most likely the big snow ends up to our NW. But I’m just playing odds here. Maybe the unlikely outcome hits. The were due index is about to explode.

I posted the mid atl snowfall anomalies. 90% of the area finished below avg snowfall and by a lot. The only areas that did well were the immediate coast and a this strip that one wave hit. I pray to god that’s not the new bar for a “good” season.

It won't matter. If it makes everyone feel better to blame me fine. I can take it. But if me and the others who post objective analysis stop posting when it doesn't look good... when you log on each day if the only posts you see are day 15 clown maps and 3 posts a day by the posters that you know only post extra rosy optimistic takes, and there are no posts by anyone else...you will know by default it still looks like crap and will then be sad. The problem isn't the posts, its that its not snowing. You're just venting and finding things to take out your frustration on. But nothing is really going to make you feel better other than snow...and if it was snowing you wouldn't give a crap what I said.