In keeping with the temperature swings that persisted through the winter season, a pattern shift is about to send temperatures below normal across the Great lakes region through the upcoming weekend. Since mid-February, high temperatures have averaged 9.7 degrees above normal. The persistence during these temperature regimes has been high. The period from February 19th, through March 4th produced only 1 day with a below normal reading. Monday’s high of 40 was 2 degrees below normal, and is expected to be one of the milder days in the coming week. Daytime temperatures through Monday are forecast to average nearly 7 degrees below normal, thanks to a general northwest wind flow aloft. In addition to the chill, snow is possible Tuesday into Tuesday night, and again Saturday night into Sunday.