It’s been nearly five years since New York City saw more than 12 inches of snow in one storm, when Central Park recorded the largest ever blizzard at 27.5 inches in January 2016. That streak could come to an end by mid-week, with the New York subway area in or near the bullseye for over 12 inches of snow.
And it won’t be just New York. In much of the densely populated parts of the northeast, a wall of heavy snow can be seen like a large northeastern target. Some cities pick up more than half a season of snow in 24 hours.
For cities like Washington, DC, Philadelphia and New York, a big nor’easter seems like a long time ago. That’s because many of these cities have seen historically low amounts of snow this past winter. The Big Apple measured just 4.8 inches last season – the fourth least snow season on record. The least amount of snow ever recorded in New York City came in the 1972-73 season, when the city saw only 2.8 inches.
For perspective, in a normal year, Central Park equates to about 25 inches of snow, and the snowiest season of 1995-96 yielded a whopping 75.6 inches.
Sunday morning, the parent storm, which will eventually become a nor’easter, was still 3,000 miles to the northeast, about to hit the Pacific Northwest with heavy mountain snow in Washington and Oregon state.
Before reaching the East Coast, it will traverse the entire US, plunge southeast through the Rockies, and dump heavy snow into the mountains. On Tuesday, after being deprived of moisture by the Rockies, the storm will bring only a light layer of snow to the Southern Plains around Oklahoma. But by Wednesday, the storm is starting to pick up again, thanks to a shot in the moisture arm of the Gulf of Mexico.
As the moisture of the Gulf meets the cold air that sits and waits in Kentucky, the snow will begin to fly and increase in intensity and coverage early Wednesday morning as it moves across the Appalachians. Once the storm leaps over the mountains, moisture from the Atlantic Ocean will enter the system and heavy snow will erupt in northern Virginia, Maryland and Pennsylvania on Wednesday afternoon and Washington, DC, Philadelphia and New York City by early to mid-afternoon. to achieve.
The heaviest snow falls along and just northwest of the I-95 corridor. In the country’s capital, it looks like precipitation will fall like a mishmash of snow, sleet and rain. In Philadelphia, it should be mostly snow and sleet. From New York City to Boston and points to the northwest, this should be primarily a blizzard. The heaviest snowfall figures start late Wednesday through Thursday mornings, at 2 inches per hour in spots.
While it is still too early to pinpoint details, and things will no doubt change between now and midweek, there is great confidence that a series of very heavy snowfalls will pile up. The image below is a general idea of where the heaviest snow might fall, but it will likely shift slightly ahead of the event. Hartford, Providence and Boston are probably bull’s eye.
What makes this system different from so many others in recent years is the availability of cold air. As the storm sets in, temperatures over the Ohio Valley, Mid-Atlantic, and New England will be in the 1920s. Usually a storm’s southerly winds are enough to push that cold air mass out, but it won’t happen this time. That’s because a strong, cold high-pressure system over Southern Canada shows no sign of run-out, as it is stuck due to an atmospheric blockage, such as a traffic jam, upstream near Greenland. This should keep the cold air in place.
The support of this system by all reliable computer models sets this system apart from most others. Usually, there wouldn’t be that much confidence in a blizzard four to five days in advance. But since all models show more or less the same evolution and similar placement of the heavy snow, it’s a rare opportunity to provide this reliable early warning.
That said, the details are sure to change as the storm approaches. Monday evening or Tuesday morning, the picture and details become a lot clearer.