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The Mystical Month of February--Long Range Discussion


Ji

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Just now, Jandurin said:

The odds of flipping a coin is the same every time.

Assuming a fair coin.

yep...but its worth running the numbers to see if there is something to the idea of long term patterns and trends since the atmosphere isnt a coin...but the numbers show the odds of snowfall each year are about the same regardless of the previous year.  

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8 minutes ago, psuhoffman said:

I debated not even saying all this because it's going to truly depress you and maybe some others but you know what...ignorance is not the answer so here goes...

You are not using the statistics correctly.  First of all you cannot apply today's Baltimore climo averages to every time period.  In the late 1800's and early 1900s Baltimore averaged 25" of snow and their median was 26" for example.  So a 20" snowfall year then was below average and the same statistically as like a 16" year now.  You have to use the climo averages for each time period to determine if a year was above or below average snowfall.

Looking at the correct climo for each period Baltimore has had 7 periods of 4 or more straight below average snowfall in less than 150 years of records.  That isn't an insignificant total.  Twice Baltimore had 9 straight years with below average snowfall.  So think...we might have 5 more years of below average snowfall to go after this one!!!!  It happened twice before.

On top of that you cannot simply look at the pure number of times there was 4 straight below average snowfall years because yes going into any run of below average snow the odds of getting 4 or more is low...but if we already had 3 (and that is assuming we don't get enough snow the rest of the way to end up above this year) then you are looking at it the wrong way.   We have already had 3 straight below average snowfall years...what you need to do is look at past such examples and see what happened the following year and what the odds are of above vs below avg snowfall.  

There have been 34 times Baltimore just ended a 3rd straight below average snowfall winter... so what happened the next winter those 34 times?

24 times the following year was below average snowfall

10 times the following winter was above average snowfall

So by those pure statistics next year has a 71 percent chance of being below average snowfall!

That is almost exactly what the random chance of a below average snowfall winter is any given year...73%.

Yea 73%.... in the last 30 years Baltimore has only had 8 above average snowfall winters, and 22 below.  Those are facts.  Any given year our chances of having above average snowfall are only 27%.  Based on history...if we finish this year below avg next year that chance would be 29%.  That is not a statistically significant difference given the limited sample size.  In others words there is absolutely no evidence to support your claim that we are more likely to get above average snow next year because we had 3 below avg years...the odds are about the same as they are any year... a little below 30%.  

 

The most depressing part of this is Baltimore’s decline in snowfall since the late 19th century. Seems like back then they averaged right around what the northern burbs average now.

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1 minute ago, 87storms said:

icon snow maps look a lot better than the setup.  it's basically a cutter, so we'll need to hope the airmass in place is legit.

That’s why I’m skeptical of the Icon’s surface temps. From what I know, it takes a pretty incredible cold airmass to get a snowstorm from a cutter or inland runner. Happened in January 1982 and February 2015, but I’m not counting on it.

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3 minutes ago, Fozz said:

That’s why I’m skeptical of the Icon’s surface temps. From what I know, it takes a pretty incredible cold airmass to get a snowstorm from a cutter or inland runner. Happened in January 1982 and February 2015, but I’m not counting on it.

neither am i.  i don't care for digital snow.  does nothing for me.  we'll see...i can believe a thump to mix/rain in the setup the icon showed, but it's not a clean look.

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15 minutes ago, psuhoffman said:

debated not even saying all this because it's going to truly depress you and maybe some others but you know what...ignorance is not the answer so here goes...

You are not using the statistics correctly.  First of all you cannot apply today's Baltimore climo averages to every time period.  In the late 1800's and early 1900s Baltimore averaged 25" of snow and their median was 26" for example.  So a 20" snowfall year then was below average and the same statistically as like a 16" year now.  You have to use the climo averages for each time period to determine if a year was above or below average snowfall.

Looking at the correct climo for each period Baltimore has had 7 periods of 4 or more straight below average snowfall in less than 150 years of records.  That isn't an insignificant total.  Twice Baltimore had 9 straight years with below average snowfall.  So think...we might have 5 more years of below average snowfall to go after this one!!!!  It happened twice before.

 

 

You know the case could be made that even using older records for Baltimore Snow climo is not even useful anymore in this climate regime. 

Make of that as you will , but even the most skilled forecasters and long range pros now the same results in 1990, 1994 and even as recent as 2000 need to be tweaked and altered, even reconsidered due to the new climate global drivers. That means the oceans, ocean currents, salinity, global temps,  ozone, etc. 

We are in a new era.  Makes things even more so complex. 

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neither am i.  i don't care for digital snow.  does nothing for me.  we'll see...i can believe a thump to mix/rain in the setup the icon showed, but it's not a clean look.


Since the ICON is a “legit model” we can start talking it’s biases... it always overdoes cold in the MR. I distinctly recall a few times it showed rainstorms as ice storms for a series of runs when no other models does. It gets away with it because there are no fancy snow maps to show and it doesn’t display FRZA/sleet on TTT, but it definitely overdoes low-level cold.
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24 minutes ago, psuhoffman said:

I debated not even saying all this because it's going to truly depress you and maybe some others but you know what...ignorance is not the answer so here goes...

You are not using the statistics correctly.  First of all you cannot apply today's Baltimore climo averages to every time period.  In the late 1800's and early 1900s Baltimore averaged 25" of snow and their median was 26" for example.  So a 20" snowfall year then was below average and the same statistically as like a 16" year now.  You have to use the climo averages for each time period to determine if a year was above or below average snowfall.

Looking at the correct climo for each period Baltimore has had 7 periods of 4 or more straight below average snowfall in less than 150 years of records.  That isn't an insignificant total.  Twice Baltimore had 9 straight years with below average snowfall.  So think...we might have 5 more years of below average snowfall to go after this one!!!!  It happened twice before.

On top of that you cannot simply look at the pure number of times there was 4 straight below average snowfall years because yes going into any run of below average snow the odds of getting 4 or more is low...but if we already had 3 (and that is assuming we don't get enough snow the rest of the way to end up above this year) then you are looking at it the wrong way.   We have already had 3 straight below average snowfall years...what you need to do is look at past such examples and see what happened the following year and what the odds are of above vs below avg snowfall.  

There have been 34 times Baltimore just ended a 3rd straight below average snowfall winter... so what happened the next winter those 34 times?

24 times the following year was below average snowfall

10 times the following winter was above average snowfall

So by those pure statistics next year has a 71 percent chance of being below average snowfall!

That is almost exactly what the random chance of a below average snowfall winter is any given year...73%.

Yea 73%.... in the last 30 years Baltimore has only had 8 above average snowfall winters, and 22 below.  Those are facts.  Any given year our chances of having above average snowfall are only 27%.  Based on history...if we finish this year below avg next year that chance would be 29%.  That is not a statistically significant difference given the limited sample size.  In others words there is absolutely no evidence to support your claim that we are more likely to get above average snow next year because we had 3 below avg years...the odds are about the same as they are any year... a little below 30%.  

 

Nah that doesn't depress me...Even if next year is below average, we could still get above average the following year. I think we're defining "average" differently...I look through the entire history and use 20" as the average (since that is what one chart Ive been using calculated as such through last year). Looking up and down the list, I only saw below 20 inches after 3 previous <20 inch years maybe three times. And only once was it below 20" after 4 consecutive years (and that was the 1970s). 

Now...if you're saying that average wasn't defined the same way in say 1960 as it is now (like if average was defined as 25 inches back then), then I guess I can kinda see that...I've been applying the 20" mark to all of recorded weather history. But now, even if you applied it to winters from 1980 on...the 20" trend is still there, with one period of 4 consecutive sub-20 inch winters. Now just because it hasn't happened in awhile doesn't mean it can't--I get that. But fact remains...long runs of sub-20 inches don't happen that often.

But again...I see your perspective as well. So, we shall see :)

(Side note: There were a couple runs that were like 18 and 19 inches...that's tolerable for me...lol)

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Just now, 87storms said:

gfs shows that banana high look.  looks better than the icon imo...or at least more potential, if we can get the primary a little further south.

maybe the euro is on to something. IT owes us after busting horrible for tomorrow at 72 hours. @stormtracker Ive never seen the euro bust so bad at 72 except when it comes to giving us snow

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7 minutes ago, Fozz said:

The most depressing part of this is Baltimore’s decline in snowfall since the late 19th century. Seems like back then they averaged right around what the northern burbs average now.

Worse than the average dropping is the median... the median has dropped from 26" down to about 15".  That is a better judge of what is "typical" or normal.  The fact is...over the last 30-50 years Baltimore's climo has become pretty hostile for snow.  We "typically" get 2-3 good above 20" snowfall years a decade and the rest are below 20".  So our NORMAL winter is below 20".  How much below is kind of irrelevant to spend so much time parsing.  I mean...is there THAT much difference between an 8" year and a 15" year?  One good warning event hit vs missed...or a couple minor events...that is a fluke most of the time.  The bottom line is 70% of the time the dominant pattern will be bad for snow and we will struggle and fight to get a few snowfalls. 

The one hope for the future is the NAO.  We have been in a prolonged +AO/NAO cycle.  Since those correlate so closely with our snowfall it stands to reason that could have as much to do with the decline as global warming.  The funny thing is...our big years are getting bigger and our big storms are getting bigger, so if we actually got another -NAO cycle during this period of hyper precipitation events we could end up with an extreme run.  Look at what has been happening NYC northward lately?  A +NAO cycle shouldn't really be good for them either.  But the abundance of extreme precip events has lead to a plethora of 8"+ events for them that has overcome that.  If we get a -AO/NAO period that suppresses the boundary south more often...that could be us.  It's a pipe dream but not completely crazy.  

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1 minute ago, Ji said:

maybe the euro is on to something. IT owes us after busting horrible for tomorrow at 72 hours. @stormtracker Ive never seen the euro bust so bad at 72 except when it comes to giving us snow

tomorrow might have ended up lamer than we thought...temps are suspect leading into it and it's a quick mover.  i'm ok losing that one for the 4x4 potential wednesday.

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1 minute ago, 87storms said:

gfs shows that banana high look.  looks better than the icon imo...or at least more potential, if we can get the primary a little further south.

Or get it to transfer quicker.  There is a little more ridging compared to 6z up top.  Keep that coming in stronger and we might have something here.

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4 minutes ago, Ji said:

maybe the euro is on to something. IT owes us after busting horrible for tomorrow at 72 hours. @stormtracker Ive never seen the euro bust so bad at 72 except when it comes to giving us snow

Same.  That's why I was kinda half serious when I said it wasn't in it's prime.  When the Euro had something 4 days, we all would be excited because you just knew that thing was a lock.   Now, I don't trust it at all.  Probably crazy talk, but I'm tired of getting burned this winter.

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1 minute ago, LP08 said:

Or get it to transfer quicker.  There is a little more ridging compared to 6z up top.  Keep that coming in stronger and we might have something here.

that would help.  the gulf is open for business:

https://www.tropicaltidbits.com/analysis/models/?model=gfs&amp;region=us&amp;pkg=z850_vort&amp;runtime=2019021512&amp;fh=114

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