WesternFringe

2 minutes ago, psuhoffman said:

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. 

You are kind of proving my point by looking so intensively at the last 30 years as if they represent the data set on whole.  A running 10 to 20 year data set?  It is almost like you want to massage your numbers to show a point.  What is wrong with 136 yrs of  data points unless it doesn’t show what you want it to show? Lol

We can suck with annual snowfall.  And we can suck with almost no snowfall some years.  But no one has shown me statistically that we are sucking more than we used to suck.  We have always sucked.  Prove me wrong, with stats.  Tired of hearing the negative Nancies.

I grew up in upstate NY where we averaged 65+”

ETA:  love Bob Chill, bc he is always grounded

8 minutes ago, Ji said:

Please talk about weather

I was responding to others, but yes Ji, we can get get back to the ‘fact’ that this winter is over bc you have no blue on your models.  Forgive me.

Actually tired of hearing we are failing bc of climate change and not that we are failing (we haven’t failed yet for 22-23) bc of la nina which we all know to be a real thing.

eta:  obviously, climate change is a real thing, bc the climate has always been changing 

4 minutes ago, eurojosh said:

Not to belabor the statistics, but I'd be curious to see an analysis of how much snow in each season was a result of 'big' storms (either as a function of amount - say 6"+ or as a function of percent - say, 33% of seasonal snowfall) as opposed to spread out over multiple smaller events; my sense is that climate change reduces our overall odds of frozen precip and bunches what does fall into increasingly atypical large events - but I've no idea if the data would bear that out or not.

Yeah, that is what we have been talking about.   Would love to see someone show me that scenario with numbers, and not a “we should see larger events” explanation.  Show me the data.

18 minutes ago, pazzo83 said:

that's true - once your sample size is big enough.

Right.  And 136 is big enough 

ETA:  I will exit stage left at this point.  I am just saying, I don’t believe the doomsayers in here with regard to future snowfall.

DCA is getting more snow than they were in the 1980s.

The data show the rate of change since 1880s is low and negligible and likely due to statistical noise, but the human brain likes to find patterns, even when there aren’t any

6 minutes ago, pazzo83 said:

that's a great point - I guess you'd model it on some sort of distribution related to the exponential (beta maybe?)? 

Just treat it normally.  We don’t treat height that way, even though it is bound by zero and the mean is low.

eta: in fact, all observable occurrence data is bound by zero.  That doesn’t mean we model it’s distribution differently 

My whole point is not to be a downer, but the opposite.  Stats say these bad years recently are aberrations and that we should have some good years coming soon!  Like, good, big years!!

11 minutes ago, pazzo83 said:

yep this is what I was always taught - you need a sample size of around 30.  I think it's interesting the median is decreasing but the std deviation is increasing.  That would suggest that while overall snowfall is trending down just a bit, we are dealing with more all or nothing type scenarios (which would make sense if we are dealing with an underlying state of bigger storms but a warming atmosphere (meaning generally less snow here)).

But again, given that you need a sample size of 18+ (30?), how can you say what the median decreasing and the standard deviation even means, when the n = 14?

1 hour ago, psuhoffman said:

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. 

Also, if you had a decade of

3,4,4,4,4,5,8,20,25,30,40,45 (like we seem to do with Ninas), is 5 inches or does 17.5” encapsulate the decade snowfall better?  Not sure, just thinking aloud.

8 minutes ago, dallen7908 said:

The problem with the mean is that the distribution is becoming increasingly skewed because the mean is low and bounded by zero.  N=136 is a healthy sample size. 

 

Usually studies with n=18 and higher start to become highly generalizable to the general population and those below it do not (thus my issue with looking at decade median data, especially from recent decades). Even looking at decadal data from 1880s only gives us n=14.  That isn’t a generalizable sample size.

At least that is what I was taught at University of Virginia when I was getting my doctorate

eta:  I think looking at the slope of the standard deviation from 1880s might be useful.  Definitely more useful than median decadal data

25 minutes ago, WesternFringe said:

n = 136 isn’t such a low number, but I can run a statistical analysis of the median of decades.  
 

I think mean is more useful over 136 years than medians of decades, which are a man-made concept, but I will take a look.

Especially when I start to look at trends since the 1960s.  My n = 62 will go to n = 6

20 minutes ago, psuhoffman said:

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. 

n = 136 isn’t such a low number, but I can run a statistical analysis of the median of decades.  
 

I think mean is more useful over 136 years than medians of decades, which are a man-made concept, but I will take a look.

This is the link for my DC annual snowfall statistical analysis since 1888.  

Snowfall is barely decreasing when measured from 1880s (-.07” per year) and 1960s (-.03” per year).

Snowfall is up (+0.17” per year) when measured from the 1980s.

Most of the variability is random and statistical noise (96+%).

Doom and gloom, in my opinion, is just human error (recency effect) when interpreting recent winters emotionally.

These were my conclusions from the link above if you don’t want to view the link:

4 minutes ago, psuhoffman said:

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. 

I had 28.5” last year which was a few inches above climo for here (Augusta County).  Perspective is paramount, for sure.

23 hours ago, psuhoffman said:

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 

So one in the 40s, two in the 50s, none in the 60s, one in the 70s, two in the 80s, none in the 90s, one in the 2000s, and two in the teens.  Seems like a pretty consistent pattern.

Down to 16 degrees here and continuing to drop.  Gusts over 40mph.  Sunny.

NW of Staunton

2 hours ago, NorthArlington101 said:

Unfortunately for our I-81 comrades the 12z EURO is putting out a icier solution than earlier runs. Cut back snow totals a decent bit.

That is consistent with what LWX has been forecasting for out here in Augusta County.  An inch or two of snow/sleet with .1 to .25 freezing rain.

10 hours ago, psuhoffman said:

I agree with @CAPE that our next modoki Nino is a great test case. We underperformed our last Nino. The excuses have some validity. But if we underperform the next one…it’s starts getting harder to ignore the obvious. If we get a modoki next year and DC gets 40” then maybe it’s been more a temporary cycle. I think it’s part both. Maybe 70/30 bad pattern cycle v climate.  This would have been a bad period in any decade given the pac longwave pattern. But I think it’s been made worse. I’m curious myself to see how “muted” our snowfall is once we get a truly good and long term sustained pattern where we can’t make any excuses if it fails to produce prolific snowfall. 

This.  I have a gut feeling we can still do snow well in a modoki nino and a nice run of plentiful snow years will put this all in perspective.  Then we can better determine whether this poor run we are currently in is more cyclical in nature vs a long-term trend.  We shall see.  

28 minutes ago, IronTy said:

Like I said, same with insomnia, the harder you try the less likely it is to happen.  You have to let go your desires and then you will be rewarded.  I'm still trackin' the SER though.  

Okay, keep us posted.

26 minutes ago, WinterWxLuvr said:

IOW, how much for my house?

Well, exactly.  Do you follow this weather board to see how much other people are getting, or how much you might get?  Lol

Also, I score little events out here when most of you all have given up, this place turns to banter, and Ji is jumping out windows.

So, yes, I was asking how much the Euro showed for mby, and I am not sorry. 

48 minutes ago, TSSN+ said:

At least we ain’t the only ones going to get the shaft. Barely going to snow up around Chicago either now per euro. 

45 minutes ago, frd said:

 

An improvement with this morning's run.

Maybe I can take advantage  of the warmer waters in the C and D canal , ha !  A C&D Canal snow streamer.  I am very desperate! 

 

Does anyone have a VA zoomed in map of 6z Euro snowfall for this storm? To my weenie eyes, it looks like the 6z is depicting 6-8 inches in western Augusta County.

3 hours ago, snowmagnet said:

NC has done better than us the past five years.  

Such a blanket statement that it is almost meaningless.  It matters where you live in VA and where you live in NC.  I eked out 28” last year here in the valley (augusta county).   Pretty sure most of NC didn’t do better than that.

On the other hand, I am sure the mountains of NC do better than VA Beach at accumulating snow.

1 hour ago, clskinsfan said:

18z NAM with some Shen Valley love with the first wave. Nothing special but an inch or two is still possible. 

Also, there is still frozen falling at the end of its run for far western and northernmost VA.

3 hours ago, Terpeast said:

Agreed. I don’t think this is a good pattern to begin with. By that I mean what’s actually out there in reality, not what has been depicted on model maps 7+ days out. There’s a difference, and the “good” pattern the models told us was coming did not fully come to fruition. 

Yes we got the -nao, but we did not get the +pna (which is even more important in Dec than Jan-Feb)

Having all these cutters is about what we would expect from a La Nina. 

Meanwhile, my buddy in Deadwood, SD just got a record 5 feet in a couple days.  If snow is the measure, there are winners and losers in all patterns.