psuhoffman

Look at some of the -pna snowstorms in the 60s. It can happen. Especially if that 50/50 and Hudson high combo verify. But yea what could go wrong is more likely because snow is never the most likely outcome unless it’s that rare -NAO El Niño situation.

Only

Ask him why he thinks it’s going to be warm

@Stormchaserchuck1 you can’t claim every non snow scenario as your win. Of course not snowing is the most likely outcome. There are a ton of permutations and most end in no snow. But you can’t say “it won’t snow because the storm will be too warm, or suppressed, it just miss us, or over amped and track NE. Well duh. Ya likely one or those lol. You mean it’s not likely all the multitude of things we need to go right to get snow will all happen. Nostradamus over here.

@mitchnick. FWIW all The ensembles think the bigger risk is an over amped miss to our NW

Euro trend last 24 hours. If it did keep this up maybe another 2 more equivalent shifts and it would be a hit.

Op euro did move in the right direction the last 12 hours but it’s taking baby steps and we’re gonna need a bigger jump here at some point.

Let’s see what the eps says. 18z it was still suggesting the euro op wasn’t necessarily the most likely outcome. EPS beats the op at this range still. But this is complicated. And our luck has sucked lately. But I’ve liked this threat window for a week now. It’s legit. But complicated and requires phasing. We sometimes win with that though and we’re due. I keep saying that. When is this we’re due index supposed to kick in??? @Bob Chill

Yea icon trended to a stronger wave 1 and suppressed wave 2. AIFS went in between. Ggem went the other way at 0z. But across guidance the weaker that Friday thing is the stronger the Sunday storm and vice versa. Which makes sense. Conservation of energy in a limited space and all that jazz.

Euro is more amplified and slower with the Friday/Saturday wave. The result is its suppressing the flow behind it and absorbs what is the next wave on other guidance

Ggem just came around. I’d wait a run to assume it’s settled on a final idea. All the guidance right now still has a healthy enough primary that we get a good snowstorm of not the HECS places east of us would get. There is time to see it adjust either way. My bigger fear is the primary trends dryer and it becomes a pure miller b which would carry the threat of a real screw job up here.

Now if they did happen can it go in my book? That is a very valid concern and odds favor a miss to the east in a Nina but not EVERY time goes that way, so we can’t just assume. But yes my biggest fear would be a weaker primary with a late bombing tightly wound miller b that crushes east of us. That’s the hecs MO for Nina

I was talking to @TSSN+ and @HighStakes earlier this evening and said March 58 was a decent analog in terms of the general setup. March 58 maxed out so don’t expect that. The issue with analogs is often the analog used was the max event for that type of pattern and 99/100 repeats of the same setup won’t reach that level or extreme. Although the potential exists if it went perfectly. A more likely outcome is always a less extreme version.

How’s the @Maestrobjwa storm coming along.

no one is forcing you to read the stuff you don't like

I didn't just use the numerical index, when I looked at each event I looked at the 5/3/1 days loading patterns and adjusted if the numerical index was obviously misleading. NAO had to be adjusted a lot when a block in the western NAO domain was cancelled out by heights in the eastern NAO domain which isn't relevant to our pattern as much. It would erroneously show up as a neutral or positive NAO when in fact there was an NAO block.

I can do that someday, not going to do that tonight lol. But the issue is ridges are becoming more significantly anomalous. So you won't see as many crazy anomalies in the past because they didn't exist as much. We are seeing more and more positive anomalies now...which yea makes it harder to overcome a hostile pacific...which is why we aren't snowing as much!

Correct I fixed it, we did have 15 snowstorms with 3 of 4 indexes hostile but none with all 4. Sorry...good catch

Edit.... my bad, I had an error that I just fixed. So... there were no warning events with all 4 indexes hostile...HOWEVER...there were 15 warning events with 3/4 of the indexes hostile. That is a significant amount of our snowfall! Additionally, historically the AO/NAO was more important that the pacific. We only had 18 warning snowstorms with a hostile AO/NAO help but we had 35 warning snowstorms with a hostile PNA pattern! This has flipped recently, in the last 10 years the pacific has dominated in a way that is not historically normal, and is very problematic because historically arctic pattersn driven by huge EPO/PNA ridges are NOT the way we get snowy pattersn, they are typically cold/dry patterns. Our snowiest patterns used to be -AO/NAO driven with a flawed pacific...this would direct pacific waves into the west and then would then run into the compressed flow over the east and be forced under us and it would be just cold enough to snow. Think 2010. That's our snow look. Not some huge EPO/PNA ridge where our flow is right off the arctic and its just cold...but dry because there are no pacific waves everything is diving down the backside of the eastern trough...we just saw what that typically looks like the last 3 weeks!

There were several examples in February, most notably one in mid Feb 1997 that was a 6-8" snowfall across Maryland in what was an otherwise god awful pac puke pattern. There were a couple examples in March also. Actually seems there was a pretty even distribution with one in November and a couple December events...January did have the most with 4. But a lot of those fringe season ones were a LONG time ago so... Here is an amazing stat....15/88 warning snows happened when 3/4 indexes were wrong! Now Chuck is trying to convince us if one of 4 or 2 of 4 factors are bad...its game over, which lately it has been...but he also says we shouldn't think anything has changed. Below is the index breakdown of all of Baltimores warning snowfalls from 1948-2019 and you can see there are quite a few where 1 or even 2 of the indexes are hostile including plenty of hostile EPO/PNA patterns. Obviously there was MORE snow when everything was good...but it wasn't as radically necessary to have a perfect pattern historically as it has been lately where if one or two things go wrong the whole thing goes to hell in a hand basket fast! EPO/PNA/AO/NAO - - - - 16 + + - - 13 - + - - 11 + - - - 10 - - + + 9 + + + + 6 - + + + 3

Thank you, that was very informative...and also incredibly depressing. Implies, as I feared, some of the pacific issues we are having are more than just "its cyclical and we will break out of it". Don't get me wrong there are moving parts here and some of it is cyclical, we most definitely are in a -PDO cycle which is making some of it worse...but the theory here seems to be a la nina base state in the north pacific is the result of longer term changes related to the elephant. I've heard it before, makes sense...and is depressing. I have some questions regarding arctic amplification and any possible benefits. I think it's possible that when things go good...they could go VERY good...hence years like 1996, 2003, 2010, 2014. But there is a statute of limitations to how far that effect can last in a warming base state. For example, we are seeing mid level ridges linking up with high latitude ridges more and more...at some point that will simply be the normal every time and the benefit of high latitude ridging will be negated once troughs are no longer forced to cut under and everything simply amplifies into huge full latitude ridges and troughs. That isn't good even when we get under the troughs since a full latitude trough is typically just cold and dry and trasient. That's why i scream when someone breaks out a 1993 analog from 15 days out because the pattern that produced 1993 superstorm can do that...but 99.9% of the time that kind of full latitude trough/ridge configuration is simply a cold front and a few days of cold dry. Sure we could see more super massive storms but most of the time we will just see more warm/wet cold dry winters....heavy on the warm...is my guess. Also... does arcic warming really help if the whole base state is warmer? It's not really the warmth in the arctic that helps us its the flow created by a ridge there and how it compresses the mid latitude flow under it. If it's simply warmer up top does that do the same thing to the same extent? EHH? I don't know I am asking. Just spit balling what some of the implications of what I read would be for us. I see some ways in which it could help...could...but I see a LOT of ways in which it is already tangibly hurting us so...not thrilling lol

Preview: he can’t

A Hudson high acts to compress the flow in a way similar to a block! It’s why there is a whole subset of snows I found when breaking them down that look a lot like (looks up) THAT! Problem is they’ve gone extinct lately! This setup used to work a lot! Lately they seem to all end up warm or north. But I guess we can roll the dice again. Had to work eventually right?

Like I said to CAPE NW loses its advantage if it’s too warm when it’s warm! When it’s truly cold the odds of a wave hitting here v DC or Richmond is pretty even. I used to her more (and state college) because it used to snow in bad patterns a lot more up here. I can list sooo many 3-5” snows during pac puke warm regimes that were rain for 95. Those have gone away, hence our advantage is significantly muted. Not gone. I still her more. But recently the spread between here and CAPE isn’t as big as it once was. Same phenomenon is affecting state college. You have to get up into New England to get steady snows doing bad patterns now.

I don’t think the phenomenon is purely Nina. You’re right WRT average places SE or 95 are doing better. But the issue is the season places NW had an advantage wasn’t in cold patterns. When it’s arctic cold the odds of you getting snow are actually similar to me! I might eke out slightly more from upslope but it’s negligible. The reason I average so much more is because I’m supposed to have a HuGE advantage RIGHT NOW! Today is supposed to be a rainstorm for 95 and a 3-4” snow up here. The advantage here is in bad patterns we eke out snows that 95 SE can’t! But the last 10 years those aren’t happening. In bad patterns it’s so warm lately they don’t work! So we snow the same amount as you when it’s cold and we don’t snow at all just like you when it’s warm.