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Weather data unfiltered by human memory

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“Ugh! This winter was so cold!” That’s what my brain says anyway. It’s no secret that I’m not a fan of winter weather. So, when you ask me what I thought of this past winter, my reflexive answer is to focus on the historic snow storm in early December and the ridiculous cold snap (but not as ridiculous as last year) in January.

The crazy thing is that I know I’m wrong.

I understand that I see winter through a filter because that’s what humans do. Each of us has our own personal way of filtering the information we receive from the world around us, which in turn affects how we think about the world we experience. In fact, we usually have more than one. I have a filter for winter. I have a filter for how I assess people. I have a filter for how I decide what new information I want to understand or ignore. Sometimes, I have to remind myself that I’m using my filter again.

For example, this winter wasn’t that cold despite what my filter wants me to believe. In fact, according to the Quarterly Climate Impacts and Outlook published by the Southeast Regional Climate Center earlier this month, the region had its ninth warmest winter on record. The report says the following:

“While daytime maximum temperatures were near normal for most of the region, nighttime minimum temperatures were much above normal; in fact, every state in the region was ranked in the top tenth warmest minimum temperatures for 1895-2018. This was due in part to plumes of moisture streaming northward from the Gulf of Mexico, producing many clouds and much rainfall (4th wettest winter on record for the Southeast).”

You might be asking yourself what plumes of moisture have to do with warmer minimum temperatures. The more moisture the atmosphere contains, the higher the dewpoint. As a general rule, the actual air temperature cannot go below the dew point. So, more moisture in the air leads to higher minimum temperatures.

On a larger, national scale, many people are claiming that the colder weather across the middle of the country this year is proof that the earth isn’t warming. Their filter seems to be that if it didn’t happen in their backyard, it just didn’t happen. However, if you look at the global temperature maps for the winter, you’ll see that with the exceptions of a few places in the world, it was warmer than normal overall.

NCEI temperature map

The NCEI January 2019 temperature anomaly map shows warmer-than-normal temperatures in shades of red and cooler-than-normal temperatures in shade of blue.

Take January for example. The map from the National Centers for Environmental Information shows the eastern halves of the United States and Canada were near average with respect to temperature for the month. Parts of the southeastern Pacific Ocean and the waters off the coast of western Australia and southeastern Greenland were all cooler than average. However, much of the rest of the world registered in the above-average range.

Our filters taint our memories of weather, be it for a day, a season, or a year. If you want to know to how accurate your memory is, you can use the official records to verify it. The National Weather Service records daily almanac data at all their major reporting stations. While not every town has official records, most are located near enough to a reporting station to be pretty accurate for the purpose of answering questions like “Wasn’t that the coldest year that decade?” or “Didn’t it rain more than usual that spring?”

The information is out there. It just takes a few minutes to find it. Your tax dollars pay for the service, and the records are available online. So, there’s no real excuse to rely on memory if you have a question that needs an accurate answer.