
Those looking to step out and enjoy Cinco de Mayo festivities will need their umbrellas in much of the eastern US; a rowboat may even be more appropriate for some. A complex, slow-moving low pressure system will bring heavy downpours and drenching thunderstorms over a large area.

And while the calendar says May, some areas will see snow too this weekend. While snowflakes will fly as far south as northern New Jersey, central Maryland, and western Virginia, some of those flakes may accumulate over the higher terrain of Upstate New York , northern Pennsylvania, and the highest elevations of western Maryland and eastern West Virginia.
Those looking forward to warmer, drier conditions will need to wait in the eastern United States. An unusually potent and positioned upper level low will keep conditions colder and more wet than usual over much of the Northeast, Great Lakes region, and Mid Atlantic. There could be additional threats of frost and freeze conditions, which will delay some for getting a jump start on their spring plantings. The unsettled, cooler-than-normal conditions could linger for at least the next 5-10 days.