In today's forecast, we're tracking a potential major winter storm that could bring heavy snow and significant winter weather to parts of the United States over the next several days. Additionally, a massive blast of Arctic air could send temperatures plummeting, bringing some Americans their first snowfall of the season and the coldest temperatures we've seen so far this fall. We'll break down where the greatest chances for snow may develop, just how cold it could get, and how this major pattern change could impact millions of Americans.