Is D.C. in for a Winter Surprise ?

 

DC residents experienced a significant milestone on January 25 with 0.3” of snow.  That was the first accumulating snowfall in the Nation’s Capital in more than a year since January 18, 2020 (0.2”).  However, DC’s streak without a snowfall of at least half an inch is fast approaching two-years.  DC residents haven’t had a half of an inch of snow since February 20, 2019. 

Although meteorological winter starts on December 1 and goes through February 28, the Nation’s Capital had its fair share of March snowfall over the last decade.  Dating back to the 2010-2011 winter season, DC had six winters with below average snowfall (15.4” based on 1981-2010 statistics at National Airport).  Meanwhile, March was DC’s snowiest month of the year in four of the last 10 years.

With the exception of the 2015-2016 and 2018-2019 winters when the DC Metro Area had epic winter storms, the major snow events of the last decade have occurred in either February or March.  Three consecutive winters from 2012-2013 through 2014-2015 featured colder and snowier than average March’s.  The 2013-2014 winter season, in particular, featured several prolonged stretches of unusually cold weather in the Nation’s Capital.  To add to that, February and March 2014 each had double-digit DC snowfall totals.  Also, March 2014 produced DC’s snowiest St. Patrick’s Day on record and was also DC’s snowiest March since 1960. 

Three of the last four winters saw below average snowfall in the Nation’s Capital.  However, March 2018 was a snowier than average month with 4.5” (more than triple DC’s March average of 1.3”).  Two key lessons can be drawn from this.  Whether or not December and January have below average snowfall has little bearing on how cold or snowy February and March will be.  That depends on whether or not there’s a shift in the overall weather pattern.  The right ingredients need to come together just once to produce a major winter storm.

Also, even if Washingtonians finish with below average snowfall for the entire winter, accumulating snowfall can occur well into March.  Such was the case with 4.1” in the Nation’s Capital on March 21, 2018.  That’s why it’s important for DC Area winter weather enthusiasts to not give up hope despite nearly two years without appreciable snowfall.  My colleagues and I on the WUSA9 Weather Team are watching the prospect of another winter storm on Sunday into Monday.

Will the Nation’s Capital see Snow ?

 

Longtime Washingtonians may recall that today is the 21^st anniversary of what was dubbed DC’s “Surprise Snowstorm.”  That coastal storm was originally expected to track harmlessly out to sea, but instead brought the DC Metro Area 9” to 15” of snow.  Unfortunately, this occurred prior to the widespread usage of social media, so unless viewers watched the 11:00 p.m. forecast on January 24, they woke up to a wintry surprise on January 25.

Currently, there are two key weather trends in the Nation’s Capital.  The first is a record stretch during which DC hasn’t fallen below 22°.  The last time temperatures fell to 21° or colder was on February 2, 2019 (18°).  The coldest it has been so far this winter at National Airport, DC’s official weather reporting station, was 23° on December 26.  Not only has it not been very cold at all so far this winter, but it’s actually been unusually mild.  Saturday, January 23 was DC’s first colder than average day in nearly a month.  Yesterday was also colder than average, giving Washingtonians the first instance of consecutive colder than average days since December 26-27.

Of course, it doesn’t have to been colder than average for a significant snow event to occur in the DC Metro Area.  But that’s something else that hasn’t happened recently either.  The last time Washingtonians had even a half an inch of snow was February 20, 2019 (2.6”).  That continues an epic snow drought in the Nation’s Capital, with 24 consecutive months since DC’s last snowier than average month (January 2019). 

What separates DC’s current stretch of below average snowfall from similar streaks is that past stretches haven’t been as extreme as this one.  For example, DC had a similar two-year stretch of below average snowfall from February 2011 – February 2013, but Washingtonians had 1.7” of snow in January 2012.  That was unlike DC’s current stretch of relatively snow-free weather.

In addition to today’s storm that will continue into tonight and tomorrow, my colleagues and I are watching the potential for more winter weather late Wednesday night and Thursday morning.  Whether or not any accumulating snowfall occurs within DC city limits this week, appreciable snowfall can occur in the DC Metro Area well into March.  The winter could finish as a warmer and drier than average season, but the right ingredients only need to come together once to produce a significant winter storm.  The trend just hasn’t been favorable so far in the 2020-2021 winter for DC Area snow enthusiasts.

January Snow Emergencies in the Nation’s Capital

 

Bethesda, Maryland  (January 2016)

While DC’s record stretch without appreciable snowfall continues, significant winter storms have occurred during the second half of January.

2016:  A major winter storm enveloped the Mid-Atlantic Region on January 22-24.  Although “only” 17.8” fell at National Airport, 22.4” fell at the National Zoo and areas west and north of town saw even more.  For example, Dulles Airport had its second largest snow total on record with 29.3”, as did Baltimore with a total of 29.2” (measured at BWI Airport).  Totals of more than three feet were observed in central Maryland and parts of Virginia.

2011:  Five inches of snow accumulated at National Airport with slightly higher amounts west and north of town on January 26.  Although not an unusually high amount of snow, what made this snowfall significant was two-fold.  The timing was troublesome in the mid-to-late afternoon when most people were on their way home from work and school.  The high volume of traffic prevented road crews from plowing and treating roads and that led to many accidents.  This storm was dubbed “Carmaggedon” due to the high number of stranded motorists.  Also, this snow had a very high water content that caused it to be heavy and wet.  That made shoveling more difficult than it would have been compared to a drier snow that would have occurred had temperatures been colder.

2000: Longtime DC-Area meteorologists remember the “surprise” snow event from January 25.  The computer forecast models originally called for little to no snowfall in the DC Metro Region because a coastal storm was expected to largely go out to sea.  However, the night before my colleagues on the WUSA9 weather team recognized a major change in the storm track that ultimately led to snow totals of between 9” and 15” across the DC Metro Region.  But, since there was no social media, most people didn’t get the updated forecast on January 24 and woke up to a winter surprise the next morning.  This was DC’s largest snow event since January 1996.

1996:  A Nor’Easter brought 17.1” of snow to the Nation’s Capital from January 6-8.  That was DC’s largest winter storm since February 1983.  Unlike the 2000 snow event, the computer models did a very good job and meteorologists were able to give area residents plenty of advance notice.  With a monthly total of 23.8”, January 1996 became the snowiest January in Washington, D.C. since 1935.  As a whole, the 1995-1996 winter ranks as DC’s third snowiest on record.