DC’s winter weather outlook

 

Could DC's 2023-24 winter be snowy ? (Photo Credit: Lee Laudicina)

The nation’s capital averages 13.7” of snowfall annually, according to NOAA.  Sometimes it comes in a series of smaller storms as it did during the 2014-2015 winter season.  In other winters, it occurs primarily during one large storm such as during the 2015-2016 winter.  NOAA recently released its winter weather outlook, and my colleagues and I on the WUSA9 weather team will release ours soon. 

There are a lot of factors to consider such as the status of the El Nino Southern Oscillation, “ENSO,” which refers to the presence of El Nino, La Nina or a neutral phase, meaning the presence of neither.  It’s also important to consider the status or “phase” of the North Atlantic Oscillation (“NAO”). 

There have been a number of memorable winter seasons that could offer clues as to what might be in store for the 2023-2024 season in the DC Metro Area.  Four of the last 10 winters have been snowier than average in Washington, D.C., but none since 2018-2019.

Sometimes winter arrives early as it did during the 1989-1990 season.  November 1989 was 1.6° cooler than average in the nation’s capital and saw 3.5” of snow (seven times the monthly average).  Meanwhile, December 1989 was an astounding 11.8° colder than average in the nation’s capital, making it DC’s coldest since 1917.  A total of 12.5” of snow fell during those two months.  However, the weather pattern changed dramatically to being significantly warmer than average when January arrived.  A combined total of only 2.6” of snow fell from January 1 through March 31, 1990.  That was an ENSO neutral winter.

On the opposite end of the spectrum was the 2015-2016 winter season.  December 2015 was DC’s warmest on record.  The first measurable snowfall of the winter didn’t occur until 0.3” fell on January 17, 2016.  Less than a week later, DC residents experienced one of the largest snowstorms on record with a total of 17.8” on January 22-23.  The rest of the 2015-2016 winter season was unremarkable and DC had a seasonal snow total of 22.2”.  A particularly strong El Nino occurred that winter and was a contributing factor in the 2015-2016 winter weather events.

By comparison, the 2014-2015 winter season had a weak episode of El Nino and DC saw a series of smaller snowstorms.  At least 0.1” of snow fell on 14 days between January 1 and March 31, 2015, with a seasonal snow total of 18.3”.  Unlike the 2015-2016 winter when over 80% of the snow occurred during the record January 2016 storm, the largest daily snowfall of the 2014-2015 winter season was 4.8” on March 5, 2015.

NOAA’s winter weather outlook calls for warmer and wetter than average conditions in the Mid-Atlantic Region.  That’s fairly typical for an El Nino winter and snow-lovers shouldn’t fret since the right ingredients only have to come together once to produce a large snowfall.  That’s what happened during the 2015-2016 winter season which got off to a record warm start in December and didn’t see any measurable snowfall until mid-January.  Most of DC’s snowiest winters since 1950 have been El Nino winters, including such memorable winters as 2002-2003 and 2009-2010.