Firefighters were slowed by the snowfall Saturday when battling a two-alarm fire that displaced a husband and wife, officials said. The two-story wood frame home on Tower Brook Road caught fire at 3:10 p.m., minutes after the wife, whose name was not released, turned on an “electric baseboard heater,” said Fire Captain William Powers. The heater was on a three-season porch in the rear of the house. The fire spread from the porch to the main part of the home, causing about $300,000 in damage, Powers said. “The entire structure had heavy fire, smoke, and water damage,” Powers said. The response from fire trucks was slow due to the weather, said Powers, who described the roads as slick with low visibility. No one was injured and the fire was extinguished at around 4:15 p.m. The Rockland and Norwell fire departments also responded, Powers said.