psuhoffman

boom Ji will be happy... naw who we kidding

@frd There often is a lag time to enso's effects and so I am less optimistic than DT that a rapidly declining cold enso will help us much before March. But...it's a pretty small sample size of rapidly declining cold enso episodes and so it is hard to draw much of any conclusion. He could very easily be correct. I hope he is. I do think march is a wildcard either way. Many Nina's that were totally garbage up until March featured a cold/snowy period in March. It is not universal...1989, 2008, and 2012 were all in the analogs I compiled to this year and were wall to wall garbage winters with no help in March. But 1956, 1976, 1999, 2017, and 2018 all featured a turn to colder with some snow late. I guess "unsure" would be the best way to categorize my feelings on what impact a rapidly collapsing nina will have on our snow chances. Can't hurt though. What I would bank on more then that is simply getting some good high lat blocking before then and not having to wait for a March save. We have scored some good snow periods in Jan and Feb in a Nina but we needed blocking to do it. That's why the current signs up top are so encouraging imo. @CAPE @losetoa6 It's been quite a few years since I did my nina study, I think it was before 2017, so I wanted to refresh my memory. I also expanded my snow study to include all 2" or greater storms at BWI in Dec-Feb during Nina's that peaked at -.1 or greater since 1950. I excluded March because that is kind of a wildcard in a Nina and that is a long way off. Let's hope we aren't heading into March needing to avoid a disaster. Even expanding down to 2" I only found one storm out of 23 (and it was a kinda pathetic 3" to rain) during the 11 moderate or stronger Nina seasons that didn't feature a lot of high latitude help. It is true that a lot of those storms did feature a period of less hostility on the pac side also...but the fact there are almost no examples of even minor snows without blocking to me indicates the break in the pac puke pattern was an effect of the blocking helping to press the TPV out of western Canada or Alaska where it will tend to set up shop and sit otherwise as a response to the central pacific ridge which is a direct effect of the nina. But get a block somewhere in the AO or NAO domain and you can squeeze that feature out of there just enough...retrograde or squash the pac ridge temporarily, and make it work.

For my full study only warning level. I did look at more snowfalls a while ago for Nina specific years...I think I started the cutoff for that at 2". You have to draw the line somewhere...there are way too many 1-2" type events to do a deep analysis of all of them. At least when I am not getting paid for any of this and have to do it on my own very limited time. If I was getting paid to do it I would gladly analyze every cartopper we ever got and break down the pattern. But honestly, its kinda a pathetic state of affairs that we are drooling over the thought of 1" of snow anyways...back when I started the study I was looking at "significant" snowfalls. Due to our lack of any snow at all recently what we call "significant" may have changed since then lol. ETA: including a lot of 1-2" events also would skew the results quite a bit since you can luck into those in a pretty mediocre or bad pattern sometimes...so you end up getting not very useful results.

I would have agreed a month ago. But the AO/NAO seem to want to play nice at times so far. This upcoming pattern is one that would probably work ok if it repeats in January or February. It could work out now but it had a better chance the deeper into winter we get.

Early to mid December is really not a good time to try to rely on the Atlantic to offset the pac. When I broke down all our snows that was rarely how we got our December snowfalls. We really need the pac to cooperate early. But imo if we can keep this general idea rolling as we head later in Dec or better into January and February it should work out a few times

The NAO and AO are trending the exact opposite way from this time last year. That’s one way to offset hostile pacific forcing.

Doesn’t matter because it won’t go down exactly like any op at that range but given that h5 I would expect that storm to adjust north some anyways.

Only if you put me in 36”+. I’ve seen numerous 2ft storms up here. Yet to see a 3ft+

@DTWXRISK misunderstood my post to think I was saying we were in a strong Nina. I don’t disagree that if the Nina weakens we could salvage a decent second half. I’m just less confident than him. Enso effects often lag but not always. Either way I see his point and I respect his argument. Plus I hope I’m wrong. I would much rather be wrong with snow than right without. Last year being right didn’t make the awful winter any less awful!

Ask coastal new england how that worked out for them

Its a slight adjustment from a very good pattern actually. If there is just a bit more NAO ridging...the resulting effects would lead to a good look.

Almost as aggravating as you complaining about it

We dont really need to adjust the track so much as the temperature profile. The upper level features track perfect for us. The reason the surface ends up so far north and vertically stacked like that relatively early in its progression is the lack of any cold air. The surface low will try to seek out the baroclinic zone. Lacking one it will end up further north than it would in a colder baroclinic profile. Trust me...adjust the thermals and that surface low would be tracking perfect for us given the rest of the variables on that run. Is the adjustment we would need to the thermals possible at that range...yes. Very. It's well within a normal error. But of course it could just as easily adjust warmer. The bigger issue would be does the progression of the longwave pattern even look close to that by 162 hours?

Trend has been more -NAO which keeps us in the game wrt storm track. We will be fighting the lack of cold due to the less than ideal pacific though. If we could keep this pattern into January/February (of course no way to know if we do) I feel like something would work out sooner or later. So long as we don't start seeing signs of the NAO going super positive like last year I feel like we have a better shot this year of avoiding a dumpster fire. Everyday that I don't see a wall to wall blue ball up top across the whole EPO/AO/NAO domain I take as a positive. Keeping in mind my bar for this year is pretty low. ETA: Last year I never even bothered to get my snowblower out of the shed and prep it for the winter. I was pretty sure I wasn't going to need it. This year I moved it into the garage and tuned it up. Not saying I expect to be using it a lot...but I have a feeling it might be needed at least once. At least more of a chance than last year. Or maybe I am just telling myself that because the thought of leaving it collecting dust in the shed 2 yeas in a row is too painful to face.

Even like a fantasy storm that last for 2 runs would be ok well the models are getting better... sucky pattern = no fantasy storms

yea but we are only 1 week in to a winter that most expected to be pretty bad for snow. So to be boiling over already seems a bit much. I do get the frustration...I want it to snow bad also...but so far things are about what I expected, which is to say, not much

That's a hell of a party

What were your expectations?

1955/56 and 2011/12 are the two best examples of somewhat healthy nina's that collapsed rapidly to weak status during winter. 2011/12 was a little weaker of a peak and 1956 made it into strong nina category. 2011/12 it did us absolutely no good. 1956 we did turn cold and snowier in the mid atlantic region in March. Of course there are other variables you have to control for and a sample size of 2 is kinda small to draw conclusions.

I didn't say we were in a strong nina...I said "moderate to strong". That includes moderate which is what we are in. And up top I indicated imo we will have a better chance of pacific help if the enso drops back above -1 (weak nina). The weekly enso bottomed out at about -1.5 a few weeks ago and the tri monthlies will likely bottom out at -1.3 depending on what the next few weeks do. That puts it right in the middle of a moderate nina. Sorry if the way I worded it implied I was saying we were in a strong nina. I was lumping moderate and strong nina's together in that post to differentiate them from some of the comps that were being throw around to weak nina's which I have found have a much different atmospheric response. As you have noted...if we can get the nina back to weak later in winter we have a much better chance of cold/snow. I was just stating that until then...while the nina is still having a corresponding moderate response on the pattern we are unlikely to get the type of pacific pattern we would need absent any help on the atlantic side. Once the enso gets into weak nina territory...maybe we do. But that is still a little ways out there...I was talking about the more foreseeable future.

It’s total garbage start to finish. Any slight pac improvement is offset by the fact we lose the Atlantic by then. A WPO ridge or even a western epo ridge won’t do us any good if the NAO is positive. If the NAO is positive we would need the Epo ridge to be centered into western Canada and that is not happening in a healthy Nina. 2017 and 2018 were extremely weak Nina’s (bordering on cold neutral at times). Very different effect. Until/unless this current Nina weakens below -1 we probably are not getting any pac help and will need a combo of a slightly less god awful period (call it serviceable) and a LOT of Atlantic help. By that I don’t mean just some weak ridging but a full scale west based NAO block with stable 50/50. And yes I know how unlikely that is given recent history but don’t shoot the messenger. That’s what history of moderate to strong Nina’s say. You can barely even find minor events in moderate or stronger Nina’s without a lot of Atlantic help. If it does weaken perhaps we get some epo help later in winter.

Unfortunately the lower heights your seeing there is likely just dry cold behind the cutter. The next wave would be the chance unfortunately guidance is retrograding the TPV which pumps a ridge in the east before that next wave can get here. That could easily change with a minor adjustment at that range though.

Yea I keep noticing that for a while now the extended GEFS goes to a pretty good looking pattern in January. The pacific ridge shifts poleward more and combined with the NAO ridging forces that TPV out of AK/western Canada. That is a look we would definitely take in January. But its way out in fantasy land for now.

Where that fgen associated banding sets up is important because the low level temperature profile east of the mountains is not great. This is not a setup where very light snow over a long period of time will amount to much. You can see the temperatures above just before that fgen associated banding develops are not ideal for accumulations over east central VA. As the banding develops you can see the effect on the surface temps due to evaporation cooling and pulling some cooler air down in the column in heavier precip. This shows the effect fully a few hours later. This is a setup where outside the higher elevations you probably have to get under that band to really see much accumulating snow. On top of that we are talking about a narrow band already...so this will likely be a pretty localized thing where some places get 2" under that band where a few miles outside have some snow tv and wet ground. Where exactly that banding sets up will be a nowcast thing...but @DTWXRISK map above looks really good to me. I wouldn't really change anything from that except I do wonder if the less than 1" area in lower elevations will accumulate much at all due to surface temps outside the heavier precip but now we are really getting picky with details over 1/2 of snow lol. Anyways...good luck. Hope someone down there gets deathbanded to 3"

@Buddy1987 sorry I got really busy today. Was outside taking care of some yard work then had to do homework with my son and get done a report for a meeting tomorrow. Not sure how much I can add at this point. There are several vorts diving into the trough behind the system exiting New England. You can see the flow behind that system preventing this from amplifying and coming up the coast. That system is just not exiting in time. The southern system is picking up just a bit of gulf moisture right now though. By late tonight/early morning the southern feature starts to merge and be absorbed into one of the two northern features...you can see the the more potent upper low here..in a good spot to pull up what little gulf moisture is available. That actually would support a more significant expanse of precip if it wasn't for the suppressive flow behind the exiting storm really compressing things. All the pieces are coming together much too late for anything significant...and the coastal low is developing well off the coast...but there is just a tiny bit of an inverted trough feature to the NW. That adds a little moisture convergence. Finally there is a bit of fgen over central and southeast VA early tomorrow morning. This could be where a heavier band sets up for a time.