A rare November sudden stratospheric warming event could lead to a polar vortex bringing unseasonably cold weather to Iowa at the beginning of December, Iowa State University Agricultural Climatologist Madelynn Wuestenberg said last week.

A sudden stratospheric warming (SSW) event is a rapid increase in temperature in the stratosphere, which causes atmospheric waves that displace the polar vortex and push cold air into lower latitudes.

“In November, sudden stratospheric...