National Weather Service forecasters Saturday morning issued a hazardous weather outlook for the next seven days because of dropping temperatures and a potential nor'easter moving up the Atlantic coast.

The cold snap comes as more than 400,000 customers on Long Island are without electricity after superstorm Sandy slammed the region six days ago. 

Temperatures are expected to plummet into the 30s in the evenings.

"This could be a high-impact event, but the effects could be even more exaggerated because there are a lot of areas that are vulnerable right now," said Mike Layer, meteorologist with the weather service, based in Upton. "Those without power should plan accordingly."

While the colder weather has already started to move in, the nor'easter could begin as early as Tuesday night, lingering through Thursday, Layer said.

Wind gusts could exceed 50 mph, with the coastline seeing rain and areas farther inland potentially seeing snow, he said.

advertisement | advertise on newsday

By Monday, forecasters should know more about the storm, Layer said.

Last year, the area saw a late October snowstorm. The weather is a bit colder for this time of year, Layer said.

Sunday, highs are expected to be in the 50s and lows in the 30s, Layer said.