A new paper from two Dartmouth researchers looked at snowpack records in March over the 1981–2020 period in 169 major Northern Hemisphere river basins and found a disturbing trend:
We show a generalizable and highly nonlinear temperature sensitivity of snowpack, in which snow becomes marginally more sensitive to one degree Celsius of warming as climatological winter temperatures exceed minus eight degrees Celsius (17 degrees Fahrenheit). Such nonlinearity explains the lack of widespread snow loss so far and augurs much sharper declines and water security risks in the most populous basins.
In other words, you don’t see average snowfall declining bit by bit as winters warm, bit by bit. Snowfall amounts and distribution stay pretty much the same for a while but then – whamo! – falls off a cliff.
The paper was published in nature (here).
The Atlantic has an article about the research titled “The Threshold At Which Snow Starts Irreversibly Disappearing“.
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Interesting. I’ve lived in the same area of southern NH for 76 years and the winters have definitely changed. When I was a kid in the 50’s we used to fill the waterers in the hen house every evening until they started freezing overnight and then would fill them in the morning. I remember this would happen about the first week in October. While no longer on a farm, we still kept a small flock up until a couple of years ago. The freezing of the waterers overnight now happens after Thanksgiving. I also remember weeklong periods of below zero weather along the MA border. Recently, it’s a rarity to get one day below zero the entire winter.