Climate change has various and far-reaching impacts, including right here in Central Pennsylvania. We experienced months of unusually warm temperatures, and then a record-setting snowfall, so how does our recent weather relate to our changing climate?
One effect of climate change with which most are likely familiar is warming global temperatures. ABC27 meteorologist Dan Tomaso explains that 2020’s meteorological summer (June-August) was the hottest summer on record for the Harrisburg area. Three of the top five hottest summers have occurred since 2010.
This November in the Harrisburg area was the third hottest November on record, and 2020 also holds records for the 10th warmest January, the second warmest February, the sixth warmest March, the hottest July, and the second warmest August, according to a graphic produced by ABC27 chief meteorologist Eric Finkenbinder and provided by Tomaso.
Over the last several decades, temperatures have generally been climbing for all four seasons in the Harrisburg area. But even with all this warming going on, we experienced a record-setting snowfall last week.
Tomaso says an important thing to consider when looking at our recent snow is the difference between climate and weather.
“Weather refers to short-term variations in things like precipitation and temperature. Climate refers to long-term trends in those processes,” explains Robert Walter, professor of geoscience at Franklin & Marshall College.
“Periodic cold spells — just because we’re in a warmer climate does not mean we’re not going to get a few injections of cold air from the North,” says Tomaso. Walter explains that seasonal weather fluctuations are expected regardless of the overall global climate.
Tomaso says, “Individual snowstorms or rainstorms, they can’t be entirely linked to climate change each and every time. Now if we see a recurring pattern of heavy precipitation like we did in 2017, 2018, 2019, then you can kind of draw a bigger climate linkage.”
According to Walter, Central Pennsylvania can expect climate change to bring “warmer and wetter conditions,” which we may already be seeing. Tomaso explains that this is because a warmer atmosphere holds more water.
“The 2010’s, in my opinion, were the decade of rain,” says Tomaso. Between rainfall records, flash flooding, and more long-term flooding, Central Pennsylvanians have been dealing with a lot of water.
But to throw another wrench in the works, Tomaso also notes that our area has been experiencing significant periods of drought and lower-than-average precipitation. Over the summer, we had a two-inch rain deficit compared to average conditions.
Tomasso says one explanation for this is currently being researched: it’s possible that precipitation events will become less frequent but more intense as a result of climate change. Or, maybe the lack of seasonal precipitation is not part of a larger trend.
Looking ahead at the rest of the winter, Tomaso says warmer-than-average temperatures are expected, and he thinks we will ultimately end up with below-average snowfall — a gloomy prediction for winter enthusiasts.