psuhoffman

Agree with all this. But what I found (and most know) is in a Nina it’s even harder to luck our way to a significant snow without any HL blocking. A lot of that is due to a less potent stj. Without blocking in any regime our best shot is to luck into a juiced up but progressive wave. Those are really unlikely without any stj help. But that is especially pertinent to DC. They are too far west to benefit from waves that develop late as they infuse Atlantic moisture. DC needs the gulf as it’s main moisture source. Only exception is a slow moving amplified bomb. But we need blocking for that so again catch 22! So it’s REALLY difficult for DC to get a significant snow in a +NAO Nina regime. Even more so than in other enso states.

There is a quote from prince’s bride that works here

I just figure when most people outside our region want a quick snapshot they are focused on the urban corridor from DC-Baltimore. You and I are not really in the mainstream here. 2000 wasn’t that good up here (but I would take it) since it’s a lot harder to fluke to avg with a couple storms up here. But the “we” was for the main cohort in this forum. You can get clipped by late developing miller bs and coastal scrapers much easier and in a Nina that advantaged your area over DC sometimes.

We did pretty well in 2000 by our standards but all the snow fell in 2 weeks when there was blocking. The rest of the winter sucked. We can always root for a fluke like that. Actually, A few years ago heading into the 2017 nino I went back and examined the h5 look leading up to every Nina warning even at BWI going back to 1950. Every single one had some kind of high latitude help. In some cases it was bootleg and didn’t show up well on the numerical NAO. Like blocking near Hudson Bay which is actually one of our better ways to back into a snow event in a flawed longwave pattern here. But I couldn’t find a single significant Nina snow without at least a decent look up top to aid. If the NAO looks like hot garbage in a Nina we can try to luck into some kind of scraps like a front end inch or two or a clipper but we’re not getting anything of substance.

Yea so are the Cleveland Browns but no one is praising them for it

But did you say it with a Monty python French accent?

Agree, 2011 was very close to a mini 1996 type Nina repeat just got really unlucky. Even the one good storm could have been much bigger if it hadnt come when the cold was stale and we wasted the front half of the storm.

2010 wasn’t a typical Nina fail. It wasn’t a late developing northern stream system. It was a big snow in the TN valley and NC with plenty of gulf moisture. But if I remember correctly a couple details screwed us. The upper level low was really broad and the base of the trough dug a bit too deep them swung around too wide right for us. On top of that there was a weak northern stream wave that came across right in front of it that may have helped to initially suppressed the gulf system until it was too far east to help us.

comparing the week leading up to 1996 and 2010 the pure high lat block was better in 2010. The blocking in 1996 had weakened some and shifted centered west of Hudson by January. But what made that work was the monster ideally located 50/50 low and that the trough axis was perfect just to our west and centered far enough south to get some stj involvement despite the Nina. Very rare. 2010 the blocking was better but a less ideal trough axis and 50/50. But it still could have worked except there was a weird messy phase between the initial gulf wave and the NS that initially suppressed the wave to our south then pulled into the NS too late for us. It could have ended better with better timing. Problem is we need more to go perfect here being further southwest than Philly-Boston.

I know, and I know you know everything I’m saying. Just adding not refuting anything!

There are macro level patterns that are conducive for snow here. But within that there are micro level details that can determine hits v close misses. I could show you some big hits and near miss h5 plots and you couldn’t tell the difference! Chaos has a hand in this. That said Nina’s tend to be an issue because the stj is suppressed and it’s NS dominant. And that means 2 issues. Most storms, even with blocking, are later developing because they usually are cut off from deep moisture until they hit the coast. As the Furthest west of the northeast regions that disadvantages us. Second it’s hard to get the NS to dig under us enough. As the furthest south of the typical snow regions...you get the idea. So Baltimore has a marginally better shot that DC. Philly marginally better than Baltimore. NYC better than Philly and by the time you get to Boston Nina’s often are awesome there! But you aren’t going to pick up on any of the micro level details that determine Jan 1996 from Dec 2010 from any kind of range.

Him! I almost made a similar reply to yours then stopped myself thinking...why am I going to stop to respond to the crazy guy screaming on the street corner soap box?

We know day 15 scores are barely better than climo. So not shocking day 100+ is erratic and unreliable. But the models are based on sound physics. Despite what DT says they don’t show things that are physically impossible. Improbable maybe but not impossible. So what these random runs that show a colder winter paradigm say is that yes that outcome is still within the envelop of possibilities. We all know what what the likely outcome is given our Nina climo. But still within the Nina set are anomalies (1904/5, 1910/11, 1917/18, 1995/96). And we don’t have a really good predictive answer for them. If you showed me all the data from early fall 1995 I wouldn’t have expected that. And I think sometimes the desire to figure it out leads to prescribing too much significance to one factor. Yea the QBO was going negative but we have had other Nina’s with a similar qbo that didn’t lead to that outcome. I think sometimes people are uncomfortable with uncertainty and just admitting “we don’t know”. Odds favor the typical dud Nina. But maybe come March we are looking back wondering how no one saw that coming!

If I was walking down the street and some stranger said some crazy nonsense like that I would just keep walking. I think I need to live my internet life more like that...

Baltimore went over a decade without a 12" snowstorm twice, in the 40's and 50's and from 1968-1979. Baltimore went 8 years without a 12" snowstorm from 1988-1995. You were falling prey to recency bias in thinking a fluke of chance that recently there seemed to be a regularity or pattern to big snows in Baltimore was something that was likely to continue. The fact it had been a long time since we had a long extended run without a big snowstorm simply meant we were due for such a thing. I don't buy "were due" either but you could just as easily look at it that way as saying we are due for a snowstorm every 3/4 years! As for 2 foot storms... well Baltimore can go multiple decades without a storm like that! Again only recently have those occurred with such frequency and regularity. Longer term evidence suggests more randomness to our big snowstorms. Baltimore did have warning criteria snowstorms in March 18 and January 19 so it hasn't been that long since a "decent" snow event.

Baltimore’s new avg is 19.4 and median is 15.3 for 1991-2020. But I think CAPEs point with expectations is valid. Baltimore has beaten median 2 of the last 4 years and 5/7. If you used median as your goal/expectation for a “good” winter you will be satisfied more frequently. If you use avg you will be disappointed about 70% of the time. If median isn’t enough to be satisfied...well moving is the more realistic option vs expecting our climo to change.

When you just glance at it there does seem to be a lot of big winters near minimums. But there are several factors that make me question the correlation when you look closer. First is the lack of timeframe consistency Wrt the minimum. Sometimes the effect was the year of the minimum (1964). Sometimes the year after (1987/2010). Sometimes 2 years after???(1978). Sometimes the year before (1996). On top of that the way we got the “big winter” wasn’t always consistent. Sometimes it was a widespread cold snowy winter like 1978/1996. But 1987 wasn’t really a memorable winter anywhere except our local region. That lack of consistency suggests more randomness than I’m comfortable with when establishing clear causality. Third, if we’re going to stretch it to a 3 year window to make the correlation work you have to consider how much more often does a big winter occur than you would normally expect during a random 3 year window? Let’s look at that closer. More recently (last 40 years) the frequency of an above avg snow winter in Baltimore is more like 35%, but if we go back through the last 11 cycles it’s closer to 40%. During that time the avg frequency of an above avg winter is every 2.5 winters. That means most random 3 year periods would likely have one above avg winter just by random chance. Not every one but the majority. That makes this correlation potentially less impressive. Furthermore you have to adjust for averages during different periods. If we do that there was no big winter anywhere around the 1954 minimum. There was a 22” winter which was avg for that period and it was a generally crappy winter across the area but BWI was a local max. That seems a weak argument to count a year like that towards the correlation. There was no big winter near the 1902 or 1913 minimums either. The results leave us with slightly more above normal years than expected if random but only slightly. Not enough to suggest strong causality probabilities. All that said doesn’t mean we can’t get a big snow year simply from my favorite weather (and life) correlation... “shit happens”

But did it ever really work. It was too small a sample to really show true statistically significant causality correlation. Consider historically we tend to get a big winter every 3-5 years anyways. And I’ve seen winters on either side of past minimums attributed to that. So that’s like a 3 year window. Could easily have been only a very minor weak correlation and as much to do with random chance as a true strong causality. That said hope this year proves that wrong. It’s all we got.

You are actually in a better spot to try to luck into a warning level snow in a Nina without blocking. You can catch the west edge of some progressive late developing storms like are common in a Nina. DC is just too far west. Heck even with blocking they miss a lot but it at least gives them a chance. All the decent Nina snows in DC had blocking help. March 18, January 2011, March 2009, February 2006, Jan 2000, March 99, and all the 96 storms featured at least some blocking leading up to them.

@CAPE of course records are made to be broken. I’m sure there have been big snow in a Nina absent blocking if you go back far enough. I’m sure it’s possible. Just very unlikely. Kinda like 2010. But maybe this year is the 1/100 fluke. But if you told me today the NAO behaves like last winter and is wall to wall positive I would bet DC ends up under 5” snowfall!

I don’t disagree, just pointing out the fact that in a Nina DC really needs some HL blocking to get a decent snow. It was shocking how much so. In all other enso conditions DC can luck their way to a warning event without blocking. But in a Nina even cold periods absent blocking typically end up dry. No stj tends to be a big problem. Can’t luck into a progressive southern steam wave. Need a strong block to force the northern stream to dig under us and pick up some gulf moisture. I’m not saying we get blocking. And we don’t need long periods, we could cash in with transient blocking. Just saying the Nina’s that featured a raging +NAO wall to wall like last year...well they ended up like last year. We need to hope we get at least some favorable looks up top (even if only temporary) or the panic room will be very busy!

Keep this in mind though...going back 50 years DC hasn’t had a warning level snow during a Nina without some NAO blocking preceding the event. I went back and looked at EVERY Nina warning event a few years ago and found every one was set up by blocking. In some cases it was a bootleg block that didn’t necessarily tank the numerical NAO. But when I examined the h5 it was there. So absent any blocking kiss any chances of more than minor events in DC goodbye.

I do want to go back so bad. This is not a picnic for me either. First of all while I’m ok at tech stuff I am not qualified to be tech support to 120 teenagers and parents. But I am now! And there are no off hours. I’m on call all the time! And running online classes sucks imo. It’s not my thing. My work day is more stressful now I than it was before. My hours aren’t any different either. I still have to grade the same work and manage the same students and teach the same class time. Only now I have to somehow manage my sons online classes also even though I’m supposed to be teaching non stop all day. They want us to implement the IEP interventions and I have no idea how that’s going to work online! I guess I do avoid my commute but I didn’t mind that. The drive was time for me to reflect and relax and prepare it decompress from the day. This really sucks and I want to just go back to normal. So I totally get it. But I also don’t want to die and I know several students, parents, co-workers, and family in my schools community who have contracted Covid recently. Unfortunately I know a few who have passed away. It’s still around in Baltimore City. And some of the stuff I’m hearing doesn’t make me comfortable. No satisfying answer on how to ensure students wear masks. Pushes to cut social distancing to 4 feet not 6 because we have classes with 45 and even if we do a/b hybrid that’s still 20+ in very small rooms. If you saw the example test room you would think it’s just a normal classroom. Fact is our classes are so crowded I typically have to stack the desks together with no space between them to fit them all so for us a “socially distanced” room is 4 feet between desks and anytime anyone moves they are inside 4 feet. Their answers on other procedures are inadequate also. Frankly they seem like they just want the kids back but don’t have the ability to follow the necessary protocols to do it safely. But that is all specific to my school. There are districts with way fewer cases in the community that have way more resources than my school does. So my feelings do not necessarily apply to what all schools should do.

I’m going to ignore some other things I disagree with and just take issue with the absolute worst part here. What about the estimated 30-40% of school staff that are high risk due to age or health conditions...like me? If we all go on FMLA the schools can’t operate. Class sizes are out of control already. And I highly doubt they will be able to replace that many teachers in the middle of a pandemic. And the districts that are trying to go back and Hogan aren’t selling this as “let’s spread it around to get herd immunity”. They are swearing we will be safe. So are you saying they are lying and basically sacrificing us so society can move on? And if so you’re ok with that?