December Climate Could Be A Warning For A Snowless Winter?
We just had the warmest November on record in New York City and a few weeks ago we looked at the 15 warmest Novembers and found that 11 of those winters that followed produced below normal snowfall while 4 were above. You can check that story again in cased you missed it. However now that we have started December in the same warm pattern we thought we would look at the warmest Decembers and see if they can tell us about the winter when it comes to snowfall. In fact by this time next Monday we may be discussing how we are on pace to have one of the warmest Decembers on record.
When we look at the 10 warmest Decembers and what happend during the following months we find a very interesting result. One might expect that it would yield below normal winters but the stats on this are not as clear as you might think.
In this set of of 10 warmest winters here is what we find in terms of snow for the winter season where December is among the 10 warmest. I’m using 28.5 as the Central Park 146 year average.
2001 3.5 T
1984 24.1 5.5
2006 12.4 0
2011 7.4 0
1998 12.7 2.0
1982 27.2 3.0
1990 24.9 7.2
1891 25.4 T
1994 11.8 T
1923 27.5 1,5
What is interesting is that while every winter in this set finished below the average of 28.5, half of those winters did come close to normal. 5 of the winters did have measurable snowfall though all of the months but 2 showed below normal snowfall for December. It certainly says that a close to normal snowfall after a warm December is certainly possible. It is interesting to me that none of the winters in this set produced anything more that normal. In the November set we had a couple of big snow winters in that group.
Now a note of caution here. Stats are fun to look at but we are only looking at 10 winters. Since most winters over time finish with below average snowfall, these numbers may be saying less than you might think. It does suggest that a normal snowfall for the entire winter season is till possible. Also remember this is for one point and what works for one place does not necessarily work for other locations. I also would not use this as a forecast tool. Past performance is not necessarily a predictor of future results.