Prepare yourself for a wet evening in the Charlotte region, but the low pressure system responsible for our rain will turn into a monster as it moves north.

Rain is spreading into the area early Thursday afternoon, and forecasters say several hours of precipitation are likely through the evening hours. The heaviest rain from the system is expected to the south and east of Charlotte.

Meteorologists say the storm system then will move up the Carolinas coast, merge with another system crossing the Ohio Valley, and produce a monster snowstorm for New England.

Heavy snow and howling winds are expected from the suburbs of New York City into Canada’s Maritime provinces. The storm likely will play havoc with flight schedules Friday to the north.

In the Charlotte area, it will be just rain. Temperatures are in the 40s and expected to stay there throughout the day.

The low pressure system is forecast to cross the northern Gulf of Mexico and will be far enough south of the region to spare the Charlotte region heavy rain. Meteorologist Doug Outlaw, of the Weather Service’s office in Greer, S.C., said about a half-inch of rain will fall in the immediate Charlotte area.

“The heavier rain will be to the south and east, closer to the center of the storm,” Outlaw said.

The rain will be falling during the evening commute, however, so motorists should allow extra time and be prepared for possible slow driving conditions.

Forecasters say the rain will end by late Thursday night or early Friday, followed by partial clearing and nice conditions Friday. High temperatures are expected to reach the lower 60s.

Another nice day is predicted for Saturday, with highs in the mid 50s. By Sunday, another storm system will be approaching the Carolinas, so morning sun probably will fade behind increasing clouds during the day.

That will set the stage for a potential heavy rain event early next week.

“A front is forecast to be moving through,” Outlaw said. “If the front moves slowly, a low pressure system expected to form in the Gulf of Mexico could slide up the front.”

That, he said, could bring heavy rain to the area.

Farther to the north, authorities are preparing for Friday’s big snowstorm. Meteorologists say temperatures will be too warm for accumulating snow in Washington, Baltimore and Philadelphia, with the cut-off line between rain and snow being near New York City.

New York is under a winter storm watch, for the possibility of 3 to 8 inches of snow. A blizzard watch is posted for Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and Maine. In addition, blizzard conditions are possible in the Canadian provinces of Nova Scotia, New Brunswick and Prince Edward Island. Forecasters say 2 feet of snow, whipped by winds gusting to 60 mph, are possible Friday in the Boston area.