So....the big question is: When is the cold air coming? Here's what I know and what is possible: 3 years ago....back in October 2014, Cat 5, Super Typhoon Nuri was churning in the West Pacific during a hot mid October. Nuri moved into the Siberian Sea and by the middle of November, Arctic air trickled into the United States. November 2014 ended up being the coldest November in 14 years.
Bottom line: 2017 could repeat 2014. Typhoon Lan is strengthening over the Philippine Sea in the West Pacific. It is forecasted to become a strong Cat 4 possibly a Cat 5 Super Typhoon. It looks as though Lan could take a similar track near Japan this weekend and then move north.
Strong typhoons that happen in Fall can disrupt the jet stream which allows for cold air to plunge into the Central and Eastern United States. The European Model (Euro) and American Model (GFS) are in agreement that in late October into November that is exactly what will happen, as a ridge builds in the West making it warmer while a trough digs in the East making it colder.
Keep the warm coats handy and stay tuned!