The first 10 days of October were abnormally warm, as jet stream winds stayed well to our north and upper level flow was predominantly from the southwest. As of 6 p.m. Wednesday, the month’s average temperature was 67.1, a level 10.8 degrees above normal.

The warm spell included three days in the mid- and upper 80s. The summerlike weather pattern is transitioning to one more typical of autumn. Jet stream winds are forecast to deliver air from northwest Canada into the Midwest during the coming week.

The first push of colder air will sweep across the region Thursday, with reinforcing surges of polar air due to arrive early Sunday morning, and again by the middle of next week. High temperatures on Friday are expected to be in the 40s. Areas outside the city may experience their first freeze of the season.