In Baltimore this winter, it snowed often, but little.
The annual snowfall tally at BWI Thurgood Marshall Airport from November through March was 18.2 inches. That is about 2 1/2 inches below the long-term average for seasonal snowfall here, going back to 1891.
It’s the region’s largest snowfall tally since the winter of 2015-2016, which was the last of three consecutive winters with at least 28 inches of snowfall.
Measurable snow, which meteorologists define as at least a tenth of an inch, fell on 12 days at Baltimore-Washington International. That meant snow was more frequent than it has been in four years.
On average, there are 10 days with measurable snowfall at the region’s point of record. There were as many as 21 in the winter of 1961-1962, and as few as one in several winters, most recently in 2001-2002.
But the heaviest single snowfall this year at BWI was just 6.6 inches, on Jan. 12-13.
Meteorologists said the conditions were the product of the climate pattern known as El Niño, which can be associated with major snowstorms that move up the East Coast. But with this El Niño, which meteorologists say developed in January, the pattern is considered a “weak” one.
El Niño is characterized by warm ocean temperatures across the central Pacific Ocean, and can send moisture streaming across the southern tier of the United States. Some of Baltimore’s biggest snowfalls have occurred when that moisture flows into storms over the Southeast, and when high pressure over Greenland traps cold air over the eastern U.S. and steers storms up the coast.
Those conditions didn’t develop this winter, and instead Maryland repeatedly found itself surrounded by warm or only marginally cold air when wet weather systems passed through. Winters with weak El Niño patterns are associated with slightly below-average snowfall in Baltimore, according to the National Weather Service.
“There was no major coastal storm this year,” said Kyle Pallozzi, a meteorologist with the weather service’s Baltimore/Washington forecast office. “We still ended up relatively close to normal snowfall. But there really wasn’t like a blockbuster type storm.”
Counting rainfall, the region is off to another wet year, after a 2018 that was its wettest on record — about two feet above normal. There has been nearly 11 inches of liquid precipitation at BWI over the past three months, almost an inch more than normal for the first quarter of the year.
Temperatures averaged a couple of degrees warmer than normal in December and February, close to normal in January, and slightly colder than normal in March.