It's December 14th, and from Chicago through the Ohio Valley and into the Mid-Atlantic and Northeast, snowfall has be lacking so far this season. Yes, there has been a few minor events, but all of the heavier snowfalls have been mostly relegated to around the Great Lakes in the traditional snow belts. So the big question is, "Should the big cities of the Midwest and Northeast be concerned about a snow drought this winter?" The short answer is, "No." But let's dive into some historical facts to answer this question completely.
While 2021 has seen a lack of 1"+ snowfalls for a good portion of southern New England through the Midwest, areas in the Mid-Atlantic are still on track. That is because most places from Philly to Washington D.C., do not see their first 1"+ snow event until the holidays.
Average dates for the first 1"+ event along with the earliest and latest dates a 1"+ storm has occurred.
Even if there was no additional snow until 2022, it doesn't mean "winter is over." In fact, October to December typically only accounts for 15 to 25% of seasonal totals, meaning 75 - 85% of snowfall typically occurs in January through March.
Although there are times when seasonal totals have been below normal after a slow start, it's not always the case. Let's look at Boston, for example... in 2014 - 15, 2.3" of snow fell in November, then only 0.3" in December. Actually, through January 23rd, only 5.5" inches fell for the season. Then the proverbial flood gates opened, with snowstorm after snowstorm from late January through early March leading to a seasonal snowfall record of 110.6 inches! While this is an extreme example, it just goes to show above normal snowfall can still happen after a weak beginning.
So what's in store for the upcoming weeks into January? Is a pattern change in sight? Well, a few things are looking more promising towards the end of December if you are looking for snow. Ridging is expected to build into Alaska (a -EPO), which tends to shove colder air into the U.S. There are also signs of blocking over Greenland (-NAO), which typically creates a stormier pattern in the East and potentially breaks up the Polar Vortex (PV). This break up can allow pieces of the PV to dive into the U.S. promoting more cold weather. Thunderstorms in the tropical Pacific (MJO) may also turn more active, which promotes colder air east of the Mississippi. All of these factors may lend to a colder/stormier time by the end of December into early to potentially mid-January.
Signs are pointing to a pattern shift towards the end of the month.
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