How new climate data will impact interpretations of snow totals in East TN

KNOXVILLE, Tenn. (WATE) — Meteorologists use all sorts of data to craft their forecasts. When creating a long-range forecast, like our Winter Weather Outlook, one tool we use is climate data and specifically climate normals.

Climate normals tell us the average amount of precipitation and snow for an area as well as average temperatures. In 2021, new climate normals were released. Climate data is typically based on a 30-year period. In 2021 the new 30-year period between 1991 and 2020 replaced the old data that spanned 1981-2010.

This new data showed big changes here in East Tennessee. Specifically regarding snow, our average annual snowfall went down from 6.5 inches (based on the period from 1981 to 2010) to 4.6 inches. So what exactly does this mean?

This lower average annual snowfall means that now less snowfall is more typical for Knoxville. This is important to remember because we often give our winter weather forecast in ranges, with details about how close to average the totals we are predicting are. As a result, it is important to remember that less snow is now more likely.

Even though our average annual snowfall has gone down for Knoxville, there are always seasons that don’t follow the norm. Remember, climate data is an average, so it takes into account all extremes.

Recently, we picked up 6.5″ of snow back on March 12, 2022, and 2.8″ of snow on December 24, 2020.