PHILADELPHIA (CBS) — Should we start searching for the hats and gloves? Or are warmer temperatures in the forecast?
2020 started out snow-starved, but featured a very active severe weather season with a number of tornado warnings.
It will also go down in the record books as the most active hurricane season on record, with 30 named storms.
The winter of 2020-2021 features a moderate to strong La Niña, which is expected to last throughout the winter season.
La Niña refers to colder than normal waters off the coast of South America and influences ocean currents and airflow across the western hemisphere.
La Niña winters, in general, tend to be milder and less snowy than El Niño or El Niño-Southern Oscillation (ENSO) neutral winters in our area.
They generally feature an influx of mild air from the south that keeps the mid-Atlantic region relatively warm, even while parts of the Northern Plains, Great Lakes and even New England get hit by cold and snow.
The four most recent La Niña winters have a considerable spread in snowfall amounts, ranging from 4 inches to 44 inches, with an average of 23.2, which is again close to normal.
As you can see, there can be plenty of variability in a La Niña winter, dependent mostly on whether enough moisture is in place during one of the somewhat fleeting cold spells.
Out of curiosity, Kate Bilo also looked at 2005-2006. While not a perfect analog, that year held our previous record for tropical systems with 27 named storms.
It also featured a moderate La Niña during the winter. We ended up with just under 20 inches of snow that year, which is close to our seasonal average, and it was a relatively mild winter overall.
From looking at the signals and analog years, we can expect a winter which is slightly milder than average, likely with some cold on the front end but turning warmer in February.
Expect snowfalls amounts to be near average — a total of 18 to 24 inches in Philadelphia this winter is most likely.