A powerful winter storm is poised to impact the Northeast this weekend, with forecasts predicting snowfall totals ranging from 12 to 20 inches across Massachusetts. As Boston prepares for its most significant snowstorm in four years, the National Weather Service has issued winter storm warnings and advisories, urging residents to stay indoors due to hazardous travel conditions. Mayor Wu has declared a snow emergency, and parking bans will be in effect as crews work to clear roads. School closures are anticipated, and residents are advised to prepare ahead of the storm by staying off the roads during peak snowfall, which is expected to begin early Sunday and continue into Monday. Frigid temperatures are also expected, making conditions even more dangerous.