psuhoffman

This is what I suspect. I meant the mean is low and bounded by 0 like Dallen said not that the sample size is low. I think median gives a much better idea of what a "typical" winter was like during any given period of time. For example the last 16 years (this is the period of time where I've really noticed the phenomenon I am hinting at here) there have been 9 single digit snowfall seasons, 4 years between 10-20", 1 season between 20-30" and 2 BIG years above 30" that are skewing the mean. During that time the mean is over 13" but the median is around 8". 8" being much closer to what a typical winter has been in DC over that period since 9 years were single digit snowfall and only 7 were more than that. Thank you, you said what I meant but much better. You're totally right, we need a larger sample size than 10 so I wouldn't use a 10 year median. But you could do a running 20 or 30 year median. But something is going on that is not refutable which is the prevalence of single digit snowfall seasons in DC is skyrocketing lately. Looking at the data there is no 16 year period that even comes close to having 9 single digit seasons. 16 years is starting to become a bit much to continue the "its just recency bias" or "its just a short term blip" mantras. And it's not like its a little off...its way off. I know 16 years is kinda arbitrary but going back over all previous 16 year periods DC had 5, 4, 3, 5, 5, 3, and 3 single digit snowfall seasons....yet during the most recent 16 years there were 9. Even if you try to simply cherry pick the worst 16 year periods you can't get close. The worst you can find cherry picking is another 16 year period with 6 unless you overlap the current period and then you can find 7 single digit seasons, but that is only by including several of the seasons in this current 16 year period. Basically the current most recent 16 years have been the absolute worst in recorded history in DC for getting abysmal low snowfall seasons...and the next worst is a 16 year period overlapping this current 16 year period! And nothing else comes close. That seems significant to me, more significant than to dismiss with "just random chance". The mean doesn't show it as much because a few seasons have been skewing the number enough to hide what I am talking about...which is getting more frequent dreg single digit snowfall seasons . Now what we don't know is this....is this awful stretch just part of a random cyclical thing or a more permanent shift. It's very possible that if records went back further we could find similar awful periods...and perhaps we pull out of this and in the next 16 years only have 3 or 4 single digit seasons (but do you really wanna bet on that???). So I am NOT saying I know this is all due to warming (although I suspect some of it is) but what I am saying is we are in a pretty long term stretch where its more likely than in any other period in recorded history for DC to have single digit snowfall year to year. It's been a long enough period now that until we break out of it...I don't consider it just a blip. Its not been just a few years...this trend has been going on for quite a while now with just a few interruptions by some big seasons here and there. But other than those big seasons....suddenly DC's typical winter is a single digit snowfall...when that used to relatively rare in the past.

A mean of such a low number can be skewed by a few years. I’d be more interested in a statistical analysis of the median and changes in the standard deviation.

I have to admit I was extremely busy and preoccupied much of last winter and what time I did devote to snow was mostly predicated on my ski trips. But…I seem to have a VERY different perception of last winter than many. I’m seeing a lot of posts where people seek to be rooting for a repeat of last year. Here at least last year was one of the worst snowfall winters of the 18 I’ve spent in the area. Finished 18” below avg and 12” below median. I’m definitely NOT rooting for anything that resembles last year. I think this winter will resemble last year, but that’s a negative to me.

What CBM said. The low heights on the mean are from two bowling bowls that progressed through after cutters. As both shortwaves were approaching the critical area there was a WAR and full latitude eastern ridge in front.

You gonna yell at me again if I answer?

Huh….the PNA and SE ridge or WAR are EXACTLY why we wasted one of the most -AO periods ever. You’re right that guidance says that changes, history says it won’t. I’m not taking sides just saying facts.

I agree there is some of fluke in this. But 9/9 (or 13/13 if we include ninos) means something. But I don’t mean it to say there is a 100% chance of below avg snow. If we had more years of records eventually there would be an exception. I don’t think it’s impossible to get a snowy winter when I get no snow through New Years. Just the odds are low enough we haven’t captured an example YET. I also opined that perhaps as November and December warms we’re creating a climo where that is more likely.

Good test of guidance v analogs. Several of this years analogs are in that set and they say don’t get your hopes up. The guidance says we head a different direction than history suggests. Place your bets.

We got a little over an inch on Dec 27th. Picture of my kids playing in it. It was barely snow, temp 33-34, rain all around us at lower elevations. only the ridgetops really got it.

Adding El Niño’s doesn’t make they much difference up here like it does for DC. The 4 El Niño’s that started with no snow were all below avg. 2 were awful, 72-73 and 91-92. The other 2 recovered to be respectable but still well below avg snow. Overall in 97 years or records here there are only 13 years that got to January without 1” of snow. They all ended up way below avg snow and 12 of the 13 are on the list of 15 least snowy years here! So basically every single time we didn’t get snow up here by January it was a horrible snow season here. But there is a first time for anything. And for some places in the southern parts of this forum it’s not as dire where one fluke 8” snow can make the season ok.

Off the top of my head I think the non Nino years with less than 1” were 1949-50, 54-55, 58-59, 75-76, 80-81, 84-85, 2001-02, 16-17, 19-20

You know I’m just messing with ya. We all know you know what you’re talking about. Yes the pattern looks good after the first week of January. All my posts are simply pure statistics and climo based because historically Ninas that start bad don’t end well. Given the last total pattern fail I just don’t have the stomach to dive back into day 15 diagnostics. Get a legit threat inside day 5 and I’ll get excited though. Yes but it’s not always a FAIL month. What’s more typical, or was, is we get a lot of frustrating mostly misses but the DC area does get some minor snowfalls. Some 1-2” type stuff. We just don’t remember them because they were seen as fails when just NW of there (like me) got 8”. And up here getting to January with no snow is pretty rare. So yea Dec is usually a small f fail but not always a total FAIL like this. The point of my data was to show that yes we do get a lot of total fails but unfortunately we also get a lot of really bad snowfall years and they tend to be the same often. It's sad. Temps thus month are solidly below average. Precip is above average and yet...no snow So ending on a positive note, was thinking maybe since we’re losing snow climo on the edges most, and early season would logically be impacted most with the warmer SST feeding the SE ridge, in that new climo perhaps it will become more common to have a total dud Dec and still flip snowy in January. If true can’t get back what we lost in a Dec so maybe a 28” winter becomes a 24” one or something like that. But maybe this year will be the first time we went into January with no snow then ended up with a big snowfall year. It’s possible.

It could help. Or it could send the PV to the other side of the world. No way to know.

@Maestrobjwa but if you need to be talked off a ledge the sample size is too small to say there can’t be a fluke. There is probably like a 10% chance we get a result better then any of the previous cohort.

If snow affects you emotionally this much, to the point of affecting your enjoyment of Christmas, you really need to move somewhere that snow isn’t an anomaly! You also need to examine if this hobby is healthy for you. If this upset you like this why did you ask me to share the imfo and why are you here now when you know we’re staring at a no hope shit the blinds pattern setting in. There was not going to be anything good here yet you made the choice to read. I love snow but for me it’s also about the science and weather in general. But I also have other vices and joys I can simply transition to when snow isn’t gonna happen. How do you even survive April to October of snow is this central to your emotional state???

I had some snow up here in December including a 1.5” snowfall right after Xmas.

If snow statistics ruins your Christmas you might need to re-evaluate some things. I had an amazing holiday. Watched my children open presents. Played games. Had dinner with my kids and parents. Watched movies. Now I’m relaxing in bed and has a min for the first time in days and saw your post asking me to share the data a couple days ago. Why would it be depressing. We both already knew it was absolutely awful. I already saw it before and you knew because I told you “it’s really ugly” so…why did you ask to see it and why would data about snow that didn’t happen in past years have any affect on your holiday mood?

Ya we just need 3 straight cutters followed by a perfectly timed shortwave that’s washing out to be just strong enough to drop 1-2”, if it tracks absolutely perfectly. #workingout

You asked didn’t you???

Those numbers seem like a typical winter lately so at least we should be used to it by now.

A lot of those years up there were on the list of very few years that didn’t snow much up here by January 1. Just saying….

@Maestrobjwa DC snowfall in non Nino years where Manchester MD had similarly to this year virtually no snow through New Years. 3.4”, 4.9”, 2.2”, 4.5”, 10.3”, 3.2”, 3.4”, 0.6”

Merry Christmas

https://psl.noaa.gov/cgi-bin/data/composites/printpage.pl

THIS THIS THIS THIS THIS... we've wasted several blocking periods over the last 5 years because there was still mid latitude ridging despite high latitude blocking.