Washington has made it uncharacteristically late into the winter without more than a trace of snow. Like multiple other East Coast cities, including New York, the District is closing in on a record for the latest date in the season that a measurable amount of snow has fallen.
Despite the historic blast of cold around Christmas, the winter so far ranks as the 11th warmest on record. Notably, eight of the 13 warmest winters through Jan. 25 have occurred since 2002, with this winter running only 0.1 degrees warmer than last winter at this time.
Typical of a La Niña winter, a fairly persistent zone of high pressure over the Southeast has steered most low-pressure systems to the west of the Mid-Atlantic, drawing mild air up the East Coast.
Local snow woes
As of Thursday, this winter matched the sixth latest on record without measurable snow in Washington. Measurable snow is considered 0.1 inches or more. By the end of this week, this winter will move into fifth place.
D.C. averages 6.1 inches of snow through Jan. 26. The full-winter average is 13.7 inches, which means the city has typically seen about half of its seasonal snow accumulation by now.
The four latest first snowfalls on record all occurred in February. 1973 holds the record, with the first and only measurable snow of the winter falling on Feb. 23. That’s also one of two winters on record with a total snowfall of only 0.1 inches.
Locations just outside the District are also making history for late-occurring first snows.
At Dulles International Airport, the latest first-snow date on record is Jan. 27, which it will pass this weekend.
In Damascus, Md., in upper Montgomery County, where snow fell very briefly Wednesday before turning to rain, retired National Weather Service climatologist Bob Leffer measured 0.1 inches. In an email, he said that Jan. 25 first snow was the latest in 48 years of record-keeping.
Dating back to last winter, the District’s number of days without measurable snow is up to 320 — the 15th longest period on record. The record streak is 381 days that ended Feb. 12, 1960. To reach the top 10, the streaks needs to reach at least 328 days.
Snow drought also affecting Baltimore, Philadelphia, New York City
It’s a similarly snowless story heading northeast along the Interstate 95 corridor:
- Baltimore’s latest first snow is Feb. 21. On Friday, this winter will become the third latest without measurable snow.
- Philadelphia had no snow at all in 1972-1973, but other than that season, this winter is now the second latest without measurable snow; Feb. 3 is the latest date on record.
- At New York City’s Central Park, this winter is now the second latest without accumulations; if it doesn’t get any flakes before Monday, it will surpass the record date of Jan. 29.
Like Washington, Baltimore has gone 320 days without accumulation, which puts it in a tie for seventh place among longest snowless streaks.
Philadelphia’s 320-day streak marks its fifth longest on record. New York City has a 323-day snowless streak, its second longest, and the record will be broken there in less than two weeks if no snow falls.
Although interior locations of the Northeast have seen more snow than locations nearer the coast, most of the region has seen below-average snowfall this winter — with a notable exception being around Buffalo.
Snow on the horizon?
It does appear a pattern change is afoot as February gets going. How much it will help with snow is another question.
Colder air should spill into the Lower 48 and the Northeast to start the month, but the pattern may not be the most favorable for snow close to Interstate 95.
Why? From Washington to New York, the presence of a zone of high pressure in the North Atlantic, known as a “Greenland block,” can help steer storms to the south and east of the Interstate 95 corridor — keeping the cold air needed for snow locked in place. But in early February, despite cold air coming in from the west, there won’t be such a Greenland block in place, which will make it harder to hold in that cold and get an ideal snow setup.
But because early February is typically the snowiest time of year in Washington and much of the Northeast, a perfect setup is not needed for it to snow. Some computer models are hinting at the possibility of flakes around Jan. 31 or Feb. 1 and again around Feb. 4 or 5.
During February, Washington averages 5 inches and Baltimore 7.5 inches; Philadelphia and New York see 8 to 10 inches typically.