PHILADELPHIA (AP) — The fourth nor'easter in three weeks is set to smack the East Coast on the first day of spring.

The National Weather Service says the bulk of the dangerous, wind-driven snow and sleet is expected to wallop New Jersey, Maryland, Delaware and parts of eastern Pennsylvania before heading off to Nantucket early Thursday.

Sleet and freezing rain are expected on Tuesday afternoon, the first day of spring. On Wednesday, about 6 to 9 inches of snow is expected, with some areas getting nearly a foot.

Brian Hurley is the senior forecaster at the National Weather Service's Weather Prediction Center. He says four nor'easters in three weeks is highly unusual, but it happens when a weather pattern locks in.