psuhoffman

Our way is better

That actually makes sense. One of the reasons I’ve always been skeptical of this period having a high probability to produce. I’m trying to think how to articulate this. It’s like “showing your work” on a math problem you just do in your head. But think of how the flow is affected by having a huge ridge at the mid levels right under us and the Tpv right on top. The whole flow is compressed. Shred factory! That’s not the flow we want to get something to amplify near us. Ideally we want a split flow and a trough to cut across under the tpv. But I can’t because the SER is a beast so it tries to lift over the SER. That only leaves 2 likely scenarios. It can’t lift and gets shredded. It can and cuts. The in between scenario is the least likely and involved needed a thread the needle perfect balance between everything. Add on top of that what I referenced above that the cold lately isn’t even penetrating into the ridge as much as it usually does and it’s even more difficult because any weak boundary wave caused by these weaker vorts in the flow won’t have much frozen associated with them if the cold is mostly to the north of the zone of least resistance in the flow between the TPV and the SER. When I play out this steam interaction in my head the paths to win seem way harder to imagine than the fails. As @Bob Chill likes to say it’s complicated and we don’t do complicated well.

There is still a path to a win. My lament is that one of the reasons those wins are so few and far between is there are several factors lowering the odds. One example in this case coming up is the lack of penetration south of the boundary. If we had a more expansive cold dome then the path to victory is simple. Root for a stronger SW to throw moisture over it. Simple. Easy. Now we need 10,000 things to go perfectly. We need the confluence to be even stronger to compensate for the fact we have no wiggle room with the cold but that is also more suppressive and so then we need an even stronger SW but to too strong because there is no wiggle room with the cold. We’re trying to thread a needle here on everything. As for the reasons why…the analogs I mentioned were all positive NAO periods. More recently we saw in 2015 that a tpv in eastern Canada with a +NAO can be a frigid result here! Additionally in this case the NAO is more a result than a cause. The NAO trended + because the TPV trended north. We did kinda get head faked again. The tpv does get displaced and rotate across but that displacement is not nearly as severe as initially hinted. That second split I alluded to 4 days ago never happened. It fell apart on guidance, guess when, at about day 7 lol. So we got a less severe displacement which takes it into the NAO domain which causes the trend in the NAO. Instead of having the tpv under and the wave breaking pumping the NAO you end up with the opposite effect. So here the NAO was a product of the cold not making it far enough south not the cause! Before anyone gets defensive and makes this about AGW I am not stating causality. And it’s difficult to quantify any correlation with any one event. There have always been examples of blocking fails. If you look at the scatter plot it -NAO -pna snowfall months I posted there was always some duds. So we can’t say “this NAO failed because of X” regardless of what x is. There is unpredictable variability in this. Same with a tpv displacement. There are enough past fails that we can’t conclusively attribute this one to any specific thing. And that’s not what I’m doing. I’m just noting the issues and logging them. We can discuss the possible why is other appropriate threads!

I dunno even after the storm is exiting and that high is on top of us there is no snow south of like NYC on the back side. But unlike the previous high which had pure arctic origin air that high is modified polar and it’s simply not cold enough. And picking on some minor imperfection kinda misses the bigger picture. It’s not a pac puke airmass. There wasn’t some weeks long pac invasion. We had an arctic airmass in place 48 hrs out. One that took weeks to build by the way. And a weak ass POS wave obliterates it. Not some 980 cutter. Just a run of the mill NS wave comes along and the regular return flow with it routs the cold it took weeks to establish in a blink of an eye. Yea not everything goes perfect. Sure had that NS wave not come along and the arctic high had been 36 hours slower then we would have had a snowstorm. But the point is the margins. No one is claiming it can’t possibly snow. My point is it seems really obvious to me that it’s been a lot harder lately to get snow. More and more has to go perfectly.

Or the fact a TPV cuts across eastern Canada and the cold boundary never even gets that far south of us at any point! Look at previous periods a tpv was there and how cold it was here. There wetent many snowstorms in the analogs to day 8 when I checked yesterday but most were frigid periods with highs in the 20s or teens and single digit lows! We don’t even really get that cold this time.

@Ji that Feb 7 fail is the worst. We can’t even dismiss it with “pac puke”. There is an arctic 1045 high over top on Feb 5 after a week straight of epo ridge and flow off the arctic. 24 hours later a weak NS wave comes across that brings a mix of PC and MP air and that alone is enough to in 1 day rout an arctic airmass and totally wreck the thermals to Canada so bad that the next day a storm can take a perfect track with the next polar high coming across and it doesn’t matter. Do you know how unlikely it is to get snow if we need to perfectly time up a fresh arctic high exactly with a perfect track low? How often does that ever happen. Ugh. Fuck this winter. Fuck whatever the hell is going on.

So what if the low takes a perfect track with a high to our north during prime climo. Obviously the problem is the fact there was some solar flare or something.

Epic

This is exactly what I was talking about. No one was discussing AGW. Me and @CAPE were discussing a tangible phenomenon we’ve observed lately. No one mentioned anything about CC or cause. But because it might possibly be related to AGW, even though no on was discussing that, someone gets defensive and suddenly there is a AGW fight.

Yea that’s the one. That was maybe the moment my thoughts really started to solidify on some things. It was an eye opener for me. But there were several waves that winter too that had anemic precip once into the cold sector. There was a wave in late Jan that some places got like a half inch from but that was it. Decently amplified wave slid by to the south and it has barely any precip into the cold. This has been a repetitive thing. Not every time obviously. Nothing happens 100%. But this is about margins. If we lose some here and some there sooner or later we find ourselves in the mess we’re in now.

On some of the waves sure. There is no GL low on others. The TPV is long gone by that last example. Even the way way out there that cuts to kingdom come has no frozen until it way north. I’m talking about a larger scale issue not the details of one wave. This has been going on for years now. I started talking about this a lot in 2021. I’ve pointed it various times this year. Mid latitude waves aren’t producing the same area of frozen precip to the north of their track at or south of our latitude lately. I’ll go back and find one of my posts from 2021. This same thing. No tpv then.

But then you’ll miss tracking when we get a March 2001 and March 2013 redux back to back !!!

I’m glad you took the right information out of that post!

How can we miss there, I mean how does that 10 mile wide area of snow miss us???? OMG look at that whole county that gets a dusting there! How can we miss Oh Oh Oh….That’s the one!!!! Look At that!!!! That’s like 7 whole miles of sleet on the fringe there. I mean it would take you like a whole hour to walk across that frozen precip zone! Impressive Guys we got this!

Man that was like some huge 14 mile wide area of snow on those waves on the 18z Gfs. Won’t take much to win in that!

The EPS did improve slightly which was enough to pretty much keep the probabilities the same from 0z since the EPS is the highest weighted in my calculations. The GEFS and GEPS got worse. GEPS is still the best of the 3 but it was even better at 0z. Remember this is through 0z Feb 6 Odds of 1" ,3", 6" 1/28 0Z: 51%, 27%, 9% 1/28 12Z: 51%, 28%, 11%

I'm putting together a bulletin board of what we need to go right for visual support

Sorry guys...I really want this to go the other way here. I am honestly not trying to be a downer, if I liked what I saw today I would say so. But I honestly think today things trended away from what we wanted after the last 24 hours we did see some progress. I will update the numbers for a combined ensemble snow probabilities when the EPS rolls out soon but just warning you the GEPS and GEFS both took a step in the wrong direction so unless the EPS looks a lot better the numbers probably moved the wrong way from 0z.

I cant really relate to tiny things

@brooklynwx99 so far today the trends are opposite what we want. I don't think seeing the confluence relax is a good thing...what we actually want is MORE confluence but also a more amplified wave. We want them to slam into each other and fight it out. That is the snow solution with upside. A weak wave has very little potential here. If the confluence remains strong it gets squashed. IF the confluence relaxes you get this euro result. Either way we lose with a weak wave. Today the confluence trended weaker and the wave trended weaker across guidance. A lot of time to turn those trends around but they are going the opposite way of what I want to see right now.

ya it wont be squashed but that looks like a setup for rain imo. Again, the "win" scenario is very very very narrow here. The ridge axis at the mid and upper levels is right under us so the only way to suppress the boundary is with the TPV. But that leaves no room for a system. We need the perfect combo of a strong wave and perfectly timed TPV/High for it to work. Weak wave, squashed. Strong wave, TPV relaxes too much...rain. If you run all the scenarios the odds favor either squashed or rain. That's why we keep seeing MOST runs flip back and forth between those 2 extremes with very few actually showing that in between snowy solution.

Just enjoying a couple of board residents going at it again...

lol

I’m not necessarily saying this is related to anything else. Two things can be true. But it’s been a repetitive issue in recent years. I’ve pointed out over the last several years often there is very little frozen precip associated with mid latitude waves.