psuhoffman

Why you trying to get me in trouble

@Heisy another example. It’s going to be in the 40s tomorrow in Vermont with dews near 30 even with partial cloud cover, snowpack and the fact they are way north of the mid latitude thermal boundary and still in the northerly flow behind last nights wave. I ski up there in March a lot. It’s going to be a warm day for them despite being north of the storm track in a northerly flow. I’ve been up there a day or two before we get a late season snow and it was frigid cold. I remember being up there in mid March in 2013/14/15 and all 3 years some part of our area for snow in mid March and I remember how damn cold it was in Vermont. One of those years it was single digits! Yea in mid March. It was like 15 in early April in 2003 a day before that late snow that hit PA and NYC. For us to get snow we need Vermont to be like 15 not 45!

It’s not bad spacing or bad luck imo. It’s the same problem we’ve had. The wave spacing isn’t working because it’s too warm. So we need some crazy perfect unlikely spacing between waves where they are exactly close enough such that the northerly flow behind one can suppress the southerly flow ahead of Ty next but without crushing it. Ya ok. That’s just not likely. Waves being a few days apart isn’t the problem. It’s that the airmass is so blah even north of the boundary where there is southerly flow that as soon as any wave ejects from the west with any amplitude the southerly flow can blast a ridge to kingdom come ahead of it regardless of the longwave pattern. The storm is then going to track along that boundary that it was able to push way further north than the longwave pattern would historically suggest it should be. It’s a nasty feedback loop. The airmass is so marginal north of the thermal gradient I’m not even sure it would matter if one of these did track south of us unless it bombed us with like 1” qpf in 6 hours. Take last night. Places in NE PA like Hazleton at 1600 feet got 2-3” of snow from .45 qpf. Even at 1600 feet it was barely snow with a closed h5 tracking under them! And places in the valleys like Drums at 900 feet got a slushy coating. So if at 900 feet way to our north the airmass was barely cold enough to produce any snow even with w perfect track for them…what was the likely outcome in DC area even had that tracked 200 miles south? It’s just too warm.

My area is actually due for a big early April snow. Digging through old coops there were a lot of 6”+ snows in early April in the early 1900s. Even some 12”+. None recently. Of course there is that other thing that could be a reason for that lol. The progression you described is exclusive to a split flow stj dominant pattern. Even none Nino blocking regimes don’t go that way. 2016 for example, while the stj was very active so was the NS and we had to flush a couple miller b waves out of our system earlier that month before we got the NS to quiet down and allow what eventually happened. Anecdotally I’ve observed when we’re on a more noisy pattern and blocking sets in usually it leads to a major amplification in the east but that amplification is likely to be NS dominant. My theory is the blocking forces the NS to buckle and amplify under the block. Our best chance usually comes after as the pattern is deamolifyinh if a SS wave can time up right to take advantage of a temporary relaxation of the flow in the NS. This can sometimes happen in waves as the pattern cycles. 2018 produced more threats after a reload but it was just too late by then. Same is likely here. Might be too late for the first threat even.

They fall for it every time. I have college friends in the NYC area. I can’t tell you how many times I’ve told them be careful of the NAM and Euro in NS miller b setups but everytime they get excited by whatever the snowiest model is.

@Ji lastly why would you even worry about the NAM. Even the euro is dangerous here. Has a nasty track record of developing these too fast. All other 0z guidance so far trended north. The RGEM isn’t even a big hit for NYC. It’s targeting Vermont!

@Ji the only way I could see this working were if the NS wave trends even another 100 miles south and intersects in VA, and the SS wave slows down and gets captured and stalls off the Delmarva v up near NYC But that runs contrary to every typical correction we see with these. Even if guidance was showing that now wouldn’t we still kinda know it was likely to screw us over?

But it’s too late the surface low is past us. Part of the problem is how this evolves. The angle at which the NS and SS waves interact is awful for us. The NS wave is diving in from the NW. So imagine the flow around these waves. Initially before they phase the flow of the NS wave to the NW is interfering with the ability of the SS wave to have moisture transport to the west of the low. Instead the moisture transport gets focused along the inverted trough between the waves. Later once they phase a healthy CCB associated precip shield can develop to the west but look where the capture will happen? Because of the trajectory of the two waves it’s going to place at our latitude. That’s when precip will start to expend. But it will be past us before that happens. It’s more the way this evolves rather than the track that is the problem.

Didn’t we have this discussion earlier?

This is following a typical timeline progression for a blocking regime. Unfortunately we are running out of time. Weeks ago when it was becoming clear the SSW was propagating and coupling someone asked how I thought the timeline would play out. I pegged March 15-20 as when the improving climo intersects the degrading climo to produce the best threat but that the pattern itself would likely get even better after that. It’s playing out exactly that way. The best threat might come after March 20th anyways but climo is gonna be a real issue.

It was a perfect 18z run. Does exactly what we need wave 3. Gets the NS wave out in front just enough. Then it has wave 4 but just a bit suppressed. Perfect for that range. Lol Both those waves will adjust around every run but 18z Gfs showed how we could conceivably win with either. This is the first time all winter we actually had a good setup. Ya it’s sucks it comes 3 weeks into March

It’s a lot easier to be optimistic betting other people’s money.

You’re even more pessimistic than me. We’ve averaged about 50% of historical climo the last 7 years. You assume this isn’t a down cycle but just the new normal? I think we get some better periods that averages it out closer to 60-70% of what climo used to be going forward.

Our 6 worst winters, and 8 of the worst 10 all happened in the last 25 years. But its not.... oh nevermind.

We are in a cycle where both the atlantic and pacific are in a hostile decadal mode at the same time (AMO/PDO) which compounded by a bad enso period has caused what would have been a down period in any era. This would have been a bad 7 years whether it happened in the early 1900s or now. But we had similar bad cycles before and they weren't THIS bad...and there is a reason for that. There is a reason why the last 7 years is the LEAST snowy on record here and its not even close. It's not that we have never had a bad pattern stretch like this before. We have...but those bad cycles weren't as bad as this one because it was during a colder base state. The downward trend in snowfall in our area has been steady, consistent, and real for 100 years now and is unlikely (not impossible, I can't see the future) to reverse. If you look beyond the shorter term cyclical ups and downs, we have already lost about 30% of our snowfall compared to about 100 years ago. That is not a prediction, it is what has already happened. That is without factoring in the full affect of the last 7 years as I do think we are due for a reversal of fortunes, but if you do we have actually lost closer to 40% of our snowfall climo from 100 years ago. I do think a snowier period ahead at some point so perhaps it is still closer to the 30 number. But it is unlikely to be enough to reverse the longer term downward trend. The truth is Baltimore doesn't actually get 20" in a typical winter like it used to anymore and that is unlikely to be "typical" again in my lifetime. If you disagree that is fine, but I don't see where you are getting the evidence for that other than wishful thinking that a trend that has been consistent within the variables for 100 years is just suddenly going to flip.

The only thing REALLY wrong with that is its too warm IF everything there was the same but the thermal boundary was where the purple line is instead of the red line...that would be fine. Trough axis in the pac is exactly where we want it, right where it is for all our big snowstorms...REMEMBER our big snow look is NOT the same as a big cold look...almost all our big snows come with a trough under Alaska. Ridge building out west in response to kick that trough east. Super 50/50 with blocking over the top. The problem is that ridge between goes nuts because its so warm...the boundary is just too far north despite a perfectly fine longwave pattern. Yes the NS wave is there over the top and that pumps that ridging a bit more because of the phase...but even with that there is there was a colder regime in the way it would be fine. Probably would be a messy storm with a primary to our west initially but we have snowed from that a LOT in the past...even in March. Some of our huge March storms had a primary way to our west initially. Especially during a -PDO regime. Again...its JUST TOO WARM. Nothing works, no longwave pattern, no setup, nothing....if its JUST TOO WARM.

Our best threat is still after these miller B waves. But it looks like the better chance is the second of those (what would be wave 4). An illustration. This is the setup for wave 3 on the 12z GEFS. Euro 0z looked similar. What’s new compared to a few days ago is X. That NS feature coming across over the top changed things. It’s still not impossible but we need that feature to get out in front more. If they come across in tandem x suppresses Y. If X gets behind it likely pulls it to our NW. the win has to be either a perfectly timed phase OR x gets far enough in front to suppress the boundary but give Y room to develop. It’s not impossible. Todays Gfs almost pulled it off. But X has made the equation more complicated. We don’t often do complicated well. But look at wave 4 Same good longwave setup. The pattern looks stable btw and unfortunately if we weren’t about to run out of clock we likely would get a snow from this eventually. But no sign of a NS feature to complicate this wave. The next SS wave is coming out of the SW. The longwave pattern in the pac will kick it out as another ridge tries to build into the west. Blocking will force it east not north. Leads to this on gefs and eps 50/50 from whatever wave 3 does. Blocking. SS wave coming across under our latitude. No sign of a NS wave in the way. Now at this point a few days ago there wasn’t any indication of NS interference yet either. So that could pop up if the NS wave timing changes. That’s what happened to wave 3. A NS wave trended way faster and is now over the top v back in the pac. Wave 3 could still work if that trend continues and that NS wave X ends up out in front enough. Wave 4 can also work. After that I think our clock has expired regardless of how great the pattern is. Unfortunately our best pattern is coming late. But we rarely win with the initial major amplification in the east in a blocking regime. Wave 1 and 2 are really both that amplification. They used to be one wave a week ago when guidance was spitting out some crazy stupid solutions. They ended up splitting into two waves so neither is a super storm. But we score more often after the major amplification as the pattern relaxes if a SS wave can take advantage while the boundary is still suppressed. Just a shame that period isn’t coming until around the 17-24th. This is very similar to March 18 but we’re running about a few days behind from the SSW to the everything after. We all joked “wonder what happens if we got 2018 a little earlier”. The snow gods said “let’s see what happens if you get 2018 a little later hahaha”.

Is it a huge deal? no Is it better to show that than some cutter…yes

That’s exactly where you want the Gfs at that range. Joking not joking.

it was on my twitter weather feed... one of those "experts" that likes to focus on one thing or another and talks in tongues I think. I think it was a 10 year trend. So hard to say. I do think a flip to a more favorable longwave pattern cycle will help. Some of this is the fact we are getting what would be a hostile period in any era superimposed on a warmer base state. The question imo is how much does it help. Chuck just pointed out that despite the waning of the nina the pacific hadley cell is not being altered yet, and that usually precedes a nino. 2019 did almost nothing to alter that factor and I am worried that a nino wont simply cure all this. I hope it does. I really really do hope we got like 100" of snow next year. But I am curious to see how much of this can be cured simply by altering the enso state.

I keep warning people that a nino alone might not alleviate that problem

I also don't think my "emotions" are driving my points here. Actually, what I am doing runs contrary to emotions. I don't want this to be true. I think emotions are actually the reason many are so hostile and resistant to some of this data and get upset when it's presented. Actually 90% of what I have posted in this thread isn't predictive at all...its simply pointing out data and evidence of trends that have already happened. First of all this trend is not just the last 7 years. Snowfall is a very anomalous fluky thing in our region. It runs in cycles some of which have some regularity based on decadal cycles and some of which is pure fluke luck mixed in. So if you focus only on one small sample size you can skew the picture. But when you pull back and look at 100 years or more the patterns become more meaningful. Yes there are up and down cycles within the trend line but there is a downward trend within that chaos. The up periods are less up and the down periods are more down. This current down cycle is no doubt a "down period" but it's worse than the last comparable down periods of this type. This trend has been going on for a long time not just recently. It's definitely more apparent in the median than the mean because within this trend there is a phenomenon that we are also getting a few super crazy snowy years mixed in. Part of this seems to be because the frequency of HECS events has increased. This can also logically be explained by the same phenomenon causing the lowering of the snowfall median as a warmer base state with both reduce the number of snowfalls but also increase the chances of a super big snowstorm in the rarer instances that it is cold enough. There are a lot of factors here going on that in isolation each one might be hard to attribute a significant portion of this but the issue is all of these factors are all influencing things the same way, and if taken in totality I don't think its a stretch to say that is what is impacting our snow climo. Unfortunately we are in a region that is being most affected by several of these factors when it comes to snowfall, at least median, like I said the mean is less affected because of HECS events skewing the mean. But factors like the expanded Pacific Hadley cell, the Indo-PAC warm pool, and the warming gulf and atlantic basin are all impacting our area specifically more so than some other places. We don't have the latitude or elevation to survive even a small push northwest of the boundary during winter along the east coast, and unfortunately all of those factors lead to that end result. The indo pac warm pool is favoring hostile mjo phases which leaves more of our winter in shit the blinds patterns. The expanded hadley cell is shifting the jet north and causing a compressed flow over the north pacific (pac firehose) directing more warmth into the CONUS than was typical in the past. The warmer gulf and atlantic is feeding the SER. The warmer base state of the pac is favoring la nina's in the effort to balance the heat which is a bad thing for us. It's a nasty feedback loop for our snow hopes and dreams. My emotions actually make me want to resist this some. That is why I almost always bust high on my seasonal predictions. You know from my posts all summer and fall i knew this year was going to be awful. I think everyone got tired of me saying how god awful things looked wrt prospects for this winter. Part of that was a generally bad longwave configuration but a lot was me knowing what that imposed onto the current warm base state would look like for us. But when it came time for me to make a seasonal forecast I did go below avg snowfall but not nearly enoough below. Because I just didn't want to fathom a snowless winter, but in my gut I kinda knew this was very possible if not likely. But I went more hopeful in my forecast. I did that again with right now. I knew in my gut that given the extreme warm base state it was unlikely any patter was going to work out in a big way for us in March...but I didn't want to just give up on winter totally and I knew March was likely to be our only chance at a decent longwave pattern so I held out hope and said maybe we do get something in March. I am actually to optimistic wrt our snow chances because of my emotions. I sometimes ignore the data and evidence because I want it to snow and I want the data to be wrong. All that said I am also sure this is also a down cycle. We have had a run of hostile longwave pattern seasons where even in a better climo period it was likely to be a down period. This period can be analogous to similar periods in the 1950's, 1970s, and late 80's into early 90s. Those were all bad too...just not as bad. I am sure we will have a better period ahead at some point...but will it be as good as past good periods... probably not and that is the issue. I am sure the next time we get a 30" winter some will say "see the doom and gloom was wrong, everything is fine" but that isn't the point. No one is saying it can't snow anymore. We are saying it is snowing less. ANd all the data proves that. That isn't predictive its a reality we have been living for a while now. The only valid question is "how much less".

I am sure anything that falls at my place this morning would be snow...I was actually almost into baltimore when I saw the flakes. There was a very brief shower around 7:20 am and there were flakes mixed in.

It's pretty logical... a lot of those 2-4" storms of years gone by were flawed. The airmass wasn't that good. The track wasn't perfect. It came together late. That's why they weren't 10" snows lol. Now those flaws are cited for the reason snow isn't even within 200 miles of us! The other reasons is SOME of them were "clipper" type systems along the arctic boundary and that boundary just rarely makes it this far south anymore. I saw some graphic about a year ago showing how the average location of the polar jet has shifted north.

I saw a few mangled flakes on my way into work this morning.