It is Christmas Eve. Some people are doing last minute shopping. Others are preparing for their normal Sunday rituals, which might include church services or football. Some poor soul is preparing to assemble a complex gaming chair for a teenager. I cannot confirm or deny that person is me (smile). It is also the time of year when many people hope for a white Christmas. If you live in the United States, dreams of a “brown Christmas” are more appropriate this year and perhaps into the future too.
So what is a “brown Christmas?” It is not the Charlie Brown Christmas that many of us grew up watching. A white Christmas for a given area is typically defined as having at least one inch of snow on the ground. If that threshold is not met, the term “brown Christmas” is often used to describe the situation. For example, Minnesota Public Radio reports on its website that, “Most of northern Minnesota has a 100% chance of a white Christmas historically.” This year, the state has historically low snow cover as Christmas approaches according the Minnesota Department of Natural Resources. With rain in the forecast, what little snow cover is there may be washed away.
Minnesota is not the only place facing a brown Christmas. Most of the contiguous U.S. will likely not have snow on the ground. Referring to the snow depth map above, University of South Alabama climtologist Jordan McLeod posted to his Facebook page, “Something to watch this Christmas is the exceptionally low snow cover across the United States.” As of Christmas Eve morning, McLeod says only 14.6% of the country is currently covered by snow, which is one of the lowest coverages on record. In fact, experts note that the entire continent of North America is likely seeing unusually low Christmas snow cover.
While many snow lovers dream of a white Christmas to set the holiday mode, there are more serious implications of a brown Christmas for many places. Lack of rain and anomalous warm termperatures have many Canadian farmers concerned. Snow cover is important for crops like winter wheat. Snow is an very good insulator so it serves as a “blanket” as we enter the cold season.
Conditions are certainly consistent with teleconnection patterns expected during an El Niño. According to the National Ocean Service website, “…the warmer waters cause the Pacific jet stream to move south of its neutral position….areas in the northern U.S. and Canada are drier and warmer than usual.” This is a naturally-occuring climate cycle, but it is not likely the only culprit in the equation this year.
As a climate scientist, I often hear people “remind” me that climate varies naturally and always has. Of course it does. However, it is not an “either/or” proposition. It is “and.” Anthropogenic climate change is very significant part of the equation too. Along with the backdrop of a strong El Niño, this year (2023) is likely to be the warmest year on record globally and candidly, it is probably not even going to be a close race. In fact, many places in the U.S. are on track to have their warmest year on record according to McLeod.
The U.S. National Climate Assessment report was released in late 2023. Reading through the lastest peer-reviewed studies and model projections, I conclude that we may need to start dreaming of a brown Christmas. Across the spectrum of scenarios (see maps below), winter surface temperatures are projected to increase in the U.S. The average-to-warmer scenarios indicate that warming trends will continue across most of the country over he next several decades. This does not bode well for Christmas snow lovers or wheat farmers.
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