"As December goes, so goes the winter"

On the Old 7-online chat board, CPcantmeasuresnow posted how the snowy Decembers tend to lead to snow winter and December with little to no snow lead to duds in the winter.  Well I noticed on the snowfall records that from the winter of 1993-94 to the winter of 2011-12 (19 winters) there was a good prognosticator to indicate the rest of the winter (January to April). I have posted below the snow season (first column), snowfall before December (October/November) (second column), December (third column), and after December (fourth column).  

1993-94                T                           6.9"                     46.5"
1994-95                T                              T                     11.8"
1995-96               2.9"                       11.5"                     61.2"
1996-97               0.1"                           T                        9.9"
1997-98                T                              T                       5.5"
1998-99                0                           2.0"                     10.7"
1999-00                0                              T                     16.3"
2000-01                T                          13.4"                    21.6"
2001-02                0                              T                       3.5"
2002-03                T                          11.0"                    38.3"
2003-04                0                          19.8"                    22.8"
2004-05                T                           3.0"                     38.0"
2005-06                T                           9.7"                     30.3"
2006-07                0                              0                      12.4"
2007-08                T                           2.9"                       9.0"
2008-09                T                           6.0"                     21.6"
2009-10                0                          12.4"                     39.0"
2010-11                T                          20.1"                     41.8"
2011-12              2.9"                            0                        4.5"

As you can see, in all the winters above, when December has 3.0" or more (which are in italics), NYC had at least 20" of snow from January to April and when December had 2.9" or less, NYC had less than 20" of snow from January to April.  However, the December prognosticator was broken this past winter.  Before December, NYC had 4.7" of snow (from the November 7th-8th, 2012 storm in the wake of Sandy).  December had 0.4" of snow.  And from January to April 2013, it had 21.0" inches of snow. So I wonder if another streak will begin this winter.

Oh God, not another one of these from abc lol. I used to believe this until last winter. December was lame and the rest of winter got better gradually.

I think I said last year I never put a lot of emphasis on this because, climatology speaking, December is not very snow for CPK. This year could work out similarly.

Actually it wasn't broken last year. Last year saw 0.4 inches in the park in December and 26.1 inches for the season. That is slightly below CPK's 144 year average of 28.5 inches per season, so I'd call last year a wash.

Of course what happens in CPK doesn't determine what happens in other areas in the Metro. We had 65 inches of snow last year in Orange County which is 20 inches above our norm, so it didn't predict our above average snowfall correctly.

I don't put much stock in it either and I was the one who discovered it, but it's just a trend I noticed. There is no scientific background or anything else to back it up. It's more a coincidence than anything I'm sure, but a heck of a coincidence.

With that said, it is very odd that a month that averages about 5 inches of snow in NYC has seen only Decembers with 3 or less or 6 or more in the last 21 years. And it's been pretty evenly divided, 9 with 6 or more and 12 with 3 or less, and they have all determined above average or below average snowfall and in most cases way above or way below average.

I think that December data from '93 up CP has posted is incredibly accurate in predicting snowfall for the winter.If I had an indicator that gave me that percentage accuracy in stock trading, I'd be in Trump's league!

Yeah, last year it was off a bit but CPK still got nowhere near the 50 plus inches of the few years before, so I think the indicator still performed well.

As years go by, it will be very interesting to see how it holds up percentage wise in it's accuracy.

Yea but 50 in for Central Park isn't normal anyways. I've got to do some homework tonight. There was a December somewhere in this decade that we had two decent snow events and didn't see anything significant until mid February. The coincidence is weird. Kind of like early snowstorms in Octobers have lead to mild and way less snowier winters.

Well, it'll be fun watching this over the next ten years to see how it holds up.As CP said, probably a coincidence but it sure is pretty accurate anyway.

Still waiting to see someday an early December snowstorm that will match Dec 11-12 1960 when a raging snowstorm and single digit temps came roaring in.Over 20 inches where I was in NJ at the time.The Dec 2010 Blizzard came close but much later in the month.

docstox12 wrote:Well, it'll be fun watching this over the next ten years to see how it holds up.As CP said, probably a coincidence but it sure is pretty accurate anyway.

Still waiting to see someday an early December snowstorm that will match Dec 11-12 1960 when a raging snowstorm and single digit temps came roaring in.Over 20 inches where I was in NJ at the time.The Dec 2010 Blizzard came close but much later in the month.

Hey Doc: Think back, it hasn't been that long. December 5-6th in 2003 Central Park had 14.0 inches of snow, We had 20 inches from that storm in Orange County. The storm you're referring to of December 11-12 1960 had 15.2 inches in Central Park so the totals were similar. The 2003 storm I don't remember having temperatures that cold but it was recent enough that we could probably look it up.

I remember the 2003 storm vividly because it was my wife's birthday but I got the present.

CP, I don't remember that storm but it looks like the 1960 storm still beat it at CP by 1.2 inches.Will have to see if the lows got into the single digits in 2003 like the 1960 storm.

Anyway, the 2003 storm still proves out the December theory as that year ,93-94, was pretty snowy at CP.94-95 was a bust but then the king of all years for snow,95-96, came around.

So CPK is now at 6.5" for December, we'll see if the prognosticator that worked for 19 years prior to last year will work this year.

Math23x7 wrote:So CPK is now at 6.5" for December,  we'll see if the prognosticator that worked for 19 years prior to last year will work this year.

Math:

Actually the NWS has Central Park at 7.1 now.

I believe they updated the zoookeeper undercoount of 1.4 earlier in the month to 2.0 which would also change our contest winner for the first 2 inch snowfall in the park. Glad to see they're at least staying on top of (him,her) the last couple of years.

Last year the prognosticator was not incorrect it was technically correct, December saw 0.4 nches the winter in CPK saw 26.1 that is 2.4 inches below the 144 year average in Central Park.

If you want to calculate from snowfall after December it was still below normal. CPK had 21.0 inches from January 1 forward which is slightly below the Januray through April Average which is 22.4. It wasn't the definitive prognosticator it has been for the last two decades but still not wrong.

Of course as I've stated before it's no prognosticator for the whole tri state area. As example we had 65 inches of snow in Orange County last year which is well above our 45 inch average. It will be interesting to see what it brings this year which is hopefully a far above normal winter snowfall wise for NYC and hopefully for all of us.

Well, since Central Park, NY had 8.6" of snow in December, the prognosticator would indicate 20"+ from January to April. Entering today, it had 19.7" since the beginning of January. And unless the "zookeeper" completely screws us the snow measurement for today, it seems like after a one-year hiatus, the December rule is back.

Math23x7 wrote:Well, since Central Park, NY had 8.6" of snow in December, the prognosticator would indicate 20"+ from January to April.  Entering today, it had 19.7" since the beginning of January.  And unless the "zookeeper" completely screws us the snow measurement for today, it seems like after a one-year hiatus, the December rule is back.

Very True Math, and remember last year was a push.

0.4 Inches in December 21.0 inches in January through April.

144 year average in January through April is 22.1 so technically it was right last year but so close we'll call it a push.

This will make it 21 of the last 24 years it was correct with 2 pushes in there. Only wrong once still in 2004/05 when 3.0 inches in December was followed by 38.0 inches the rest of the season.

Bump

I have actually looked at winters prior to 1993-94 and tested out the December prognosticator. It turns out that while December 1977 had only 0.4" of snow, January-March 1978 had 50.1" of snow, the most famous storm being the February 1978 blizzard.

I went to the Upton's web site to get the monthly snowfall totals and when I put them onto Excel, I calculated the percentage of snow that fell in December and the highest percentage occurred during the 1912-13 season. 3.9" fell outside of December but 11.4" occurred during December. And here's the interesting part, the 11.4" all came from one storm on December 24th, and since this was the first year in which Central Park measured snow depth, Christmas day featured a snow depth of 8", making for a White Christmas.

More recently, the highest percentage of a season's snowfall occurring in December was during the 2003-04 season when 19.8" fell in December 2003 while 22.8" fell the rest of season (though I remember January 2004 being COLD!)

Who knows what this winter will being given no major east coast snowstorm in the near future.

Wow, great stuff Mike!!

Gotta admit, didn't think think Dec would have been this snowless looking at all the teleconnections a few weeks back… never mind the Christmas torch

One thing I have learned here from Frank is that the Stratosphere influences the Trophosphere, where our weather generates, and although the teleconnections looked good, the QBO reading over rode the positive influences for snow.The QBO reading for December, due next week, will tell the tale for January.

If you go by the December Prognosticator, it's not looking good for the winter overall.I'm sure I'll be stoned for saying it, but statistics are statistics.If there was an investment, a "snow" commodity, as an investor, I would "short" snow based on the December Prog. and make money due to the lack of snow.Add into this reversion to the mean after 60 plus inches last year, and the sad facts remain.

However, the December rule has been known to fail, so as a snow lover, I hope I am wrong on all the above.Next three months......VERY interesting.

I went back to 1869 in NYC and looked at winters where December had 1.8 inches or less of snow. While the majority 26 of 44 winters were below normal there were some notable exceptions like 77-78 and 65-66. The average snowfall for all 44 winters was 24.0 inches which compares to the long term average in NYC of roughly 28.4. So December is in my view inconclusive with regards to the longer term. The correlation is weak.

joecioffiwpix wrote:I went back to 1869 in NYC and looked at winters where December had 1.8 inches or less of snow. While the majority 26 of 44 winters were below normal there were some notable exceptions like 77-78 and 65-66. The average snowfall for all 44 winters was 24.0 inches which compares to the long term average in NYC of roughly 28.4. So December is in my view inconclusive with regards to the longer term. The correlation is weak.

hoping to add 2014-15 to the notable exceptions

1977-78 incoming!!

Radz wrote:

joecioffiwpix wrote:I went back to 1869 in NYC and looked at winters where December had 1.8 inches or less of snow. While the majority 26 of 44 winters were below normal there were some notable exceptions like 77-78 and 65-66. The average snowfall for all 44 winters was 24.0 inches which compares to the long term average in NYC of roughly 28.4. So December is in my view inconclusive with regards to the longer term. The correlation is weak.

hoping to add 2014-15 to the notable exceptions

yup. You also have to keep in mind that even if the rest of the winter has below 20" of snow, we can still get a significant snowstorm (even a "Godzilla") or ice storms. December 2006 was very mild with no snow (it was 72 degrees at CPK on 1/6/07) but we had two significant ice storms that winter (2/14 and 3/16-17) which were paralyzing. Also December 2007 had 2.9" of snow but there was a nice storm on February 22, 2008 that gave CPK 6" of snow (and my neighborhood 8"+ of snow). I also remember the winter of 1998-99 where after a very warm first 22 days of December (I remember very well how warm it was then, it was 75 at CPK on 12/7/98). Then a cold front came through and then CPK got some light snow on Christmas Eve (more fell over Central NJ and LI) giving us a White Christmas. CPK had only 2.0" of snow December 1998 and the rest of the winter had 10.7" (which fits the prognosticator). But two of those snow events were 1/8/99 and 3/15/99 which I remember fondly (I was eight at the time). Playing out in the snow and building a snowman, those were the days. Now, it's just viewing models and filming the snow. But we'll see how the rest of the winter goes.

joecioffiwpix wrote:I went back to 1869 in NYC and looked at winters where December had 1.8 inches or less of snow. While the majority 26 of 44 winters were below normal there were some notable exceptions like 77-78 and 65-66. The average snowfall for all 44 winters was 24.0 inches which compares to the long term average in NYC of roughly 28.4. So December is in my view inconclusive with regards to the longer term. The correlation is weak.

Joe, that 26 of 44 winters leads to a 60% possibility of the winter being just average or below.As a trader of investments (that's how I make my living), a 60% probability of making a profit puts me ahead.The December Prognosticator,IMHO,does pretty good .No offense, just my two cents.

Joe's data a bit off:

There have been 50 Decembers of the last 146 with less than 3 inches of snow, the average December in NYC has 5.5 inches.

The January through April period produces 22 inches of snow on average. If during those periods 18-26 inches falls call those as push as 20% above or below normal isn't a significant deviation one way or the other.

of those 50 Decembers the following January through Aprils saw the following.

10 between 18-26
13 above 26
27 below 18.

Statistically Decembers below 3 inches of snow in NYC the rest of the winter has been near normal 20% of the time, significantly below normal snowfall 54% of the time and significantly above normal snowfall 26% of the time.

It basically leaves our chances of the period January through April of having above normal snowfalll at 26%. I'm not liking those odds.

I call that pretty significant.

CPcantmeasuresnow wrote:Joe's data a bit off:

There have been 50 Decembers of the last 146 with less than 3 inches of snow, the average December in NYC has 5.5 inches.

The January through April period produces 22 inches of snow  on average. If during those periods 18-26 inches falls call those as push as 20% above or below normal isn't a significant deviation one way or the other.

of those 50 Decembers the following January through Aprils saw the following.

10 between 18-26
13 above 26
27 below 18.

Statistically Decembers below 3 inches of snow in NYC the rest of the winter has been near normal 20% of the time, significantly below normal snowfall 54% of the time and significantly above normal snowfall 26% of the time.

It basically leaves our chances of the period January through April of having above normal snowfalll at 26%.  I'm not liking those odds.

I call that pretty significant.

Im sorry CP IMHO you cannot simply call those a push (18-26" needs its own category).    Therefore with less than 3" in Dec there is a 54% chance at a below normal (<18" total) for the winter, a 20% chance at a normal winter(18-26", and a 26% chance of an above normal (>26" total).  Or 54% chance at below 18"-26" and 56% at greater than 18-26" .  
Put that way its more 50/50