created by dimonium_anonimo on 29/01/2024 at 17:31 UTC
32 upvotes, 1 top-level comments (showing 1)
Nov-22 through Apr-23 had some record breaking snowfall in Minnesota (probably some other places, but I don't track other places' snowfall)
We're now approaching Nov-23 through Feb-24 with only one thing that I think could be considered a snowstorm which laid down, like, 2 inches.
Is this just regression to the mean? Completely random chance? Or is there a higher chance of light snowfall the year after a winter with heavy snowfall?
Comment by DesignerPangolin at 30/01/2024 at 13:39 UTC*
20 upvotes, 1 direct replies
In some regions, there is a relatively high degree of correlation between subsequent years of precipitation (and snowfall). This is called autocorrelation. These tend to be coupled with multi-year oscillations in sea surface temperature like the Pacific Decadal Oscillation, El Nino, etc. In other regions where weather is less coupled to these oscillations, precipitation variability is more random.
Here is a link[1] to a global map that shows how tightly correlated precipitation between subsequent years is (panel a, from this paper[2]). Deep red = substantial positive autocorrelation, a wet year is likely to be followed by a wet year. Deep green = substantial negative autocorrelation, that is, a wet year one year is likely to result in a dry year the next. I see in your region, there is not a strong autocorrelation, so for you I think it's fair to say that interannual variability in precipitation is fairly random.
1: https://www.mdpi.com/water/water-11-02092/article_deploy/html/images/water-11-02092-g001.png
2: https://www.mdpi.com/2073-4441/11/10/2092
Edit: Here's a better paper[3]than the one cited above discussing lagged autocorrelation.
