Communities up and down the East Coast are bracing for heavy rain, gusty winds and chance of coastal flooding as the first nor'easter of the season moves in this weekend.

The National Weather Service said low pressure moving northward along the Northeast coast today will continue to bring widespread heavy rainfall and gusty winds to much of the Northeast today, coming to an end by Sunday as the low lifts into Eastern Canada.

Portions of upstate New York and northern New England may even see snow as mixed precipitation and accumulating snow and icing, especially in the higher terrain, are in the forecast.

Coastal flooding and strong winds are also a concern along the coast, where coastal flood warnings and advisories are in effect. Temperatures across the East will remain below normal through the weekend.

A flash flood watch was issued for portions of southern Connecticut, northeast New Jersey and southeast New York.

Widespread flooding of vulnerable areas near the waterfront is expected in New York City, with winds gusting up to 50 mph through offshore areas of the Long Island Sound and 35 mph inland.

Severe weather conditions caused New York City's annual Gracie Mansion Halloween Celebration to be postponed until Sunday.

John F. Kennedy International Airport warned passengers to check their flight status before arriving due to anticipated severe weather.

New York Gov. Andrew Cuomo deployed additional resources for Mid-Hudson Valley and Long Island in advance of the storm, urging New Yorkers to be well prepared for winter weather. Statewide, emergency services have been stockpiling generators, water pumps, sandbags and ready to eat meals.

"I do not expect this to be a destructive nor’easter but it will be a huge inconvenience to millions of people’s weekend plans in the East," said NBC News meteorologist Bill Karins. "Canceled Halloween plans and airport delays will be a common occurrence."

Here's a closer look at the impacts from the coastal storm for the Northeast today. The heaviest Precipitation (top left) will me over eastern MA/ME, heaviest Snow (top right) for higher elevations, Gusty winds (low left) for much of the area and huge waves (low right) offshore. pic.twitter.com/IjllpKfW76 — NWS (@NWS) October 27, 2018

Last week, National Weather Service warned Hurricane Willa that wreaked havoc in the Pacific could lead to weather conditions that would spawn a nor'easter off or near the Mid-Atlantic coast.

A nor'easter is a low-pressure storm with winds over the coastal area coming from the Northeast that can occur at any time of the year, but is most frequent and powerful between October and April.

The strongest nor'easters can bring crippling snow, damaging winds and destructive ocean waves.