Winter Storm Toby will become the fourth nor'easter in less than three weeks to impact the East Coast and has the potential to be one of the heaviest snowstorms this late in the season along parts of the Interstate 95 corridor, including in New York City and Philadelphia.

(MORE: Winter Storm Toby Forecast )

The calendar turned to spring with the vernal equinox Tuesday , but Mother Nature is not ready to let go of winter's fury just yet. Snowstorms can happen in late March and early- to mid-April in the Northeast Megalopolis.

In fact, in New York City, there have been 15 snow events of 6 inches or more on and after March 16, seven of which were in April.

The last time that happened was March 19, 1992, when 6.2 inches of snow piled up in Central Park. The most recent 6-inch-plus snow event in April occurred on April 6, 1982, when a 9.6-inch snowfall was measured.

The biggest spring snowstorm occurring after the equinox in the Big Apple was 11.8 inches March 20-21, 1958, according to records dating to 1869.

Winter Storm Toby has a chance to enter the list of New York City's top-five heaviest spring snowstorms.

(FORECAST: New York City )

It would not be the latest snowstorm, however. A two-day snowfall event April 13-14, 1875, dumped 10 inches in Central Park. The majority of the snow, 8.7 inches, fell April 13.

(MORE: Where March and April are the Snowiest Months )

Farther south along Interstate 95, Toby could be the heaviest and latest March snowstorm in Philadelphia, where snow records date to 1885.

The March 1993 Storm of the Century dumped a foot of snow in the City of Brotherly Love, making it the heaviest March snowstorm on record there.

If Philly picks up more than a foot of snow from Winter Storm Toby, it would earn the top spot in the city's biggest March snowstorms and would also occur just as late in the month as the 11.4-inch snowfall March 19-21, 1958.

(FORECAST: Philadelphia )

However, an even heavier snowstorm happened later in the season when 19 inches fell on April 3, 1915, followed by another 0.4 inches the next day. That holds the record for the latest-in-season snowstorm of at least 6 inches in Philadelphia.

Brian Donegan is a meteorologist at weather.com. Follow him on Facebook , Twitter and Instagram .