Chilly weather returned to the Chicago area Friday with afternoon highs clustering around 40, a drop of about 25 degrees from the record-breaking low 60s Boxing Day warmth. Despite the large temperature downturn, the Friday readings were still 5-10 degrees above normal. The chill will be brief with another major warm-up in the works this weekend as a new storm system approaches from the Plains. Chicago will lie in the storm’s rainy, warm sector where southerly winds will boost temperatures into the lower 50s Saturday and into record-breaking lower 60s territory Sunday. Temperatures will fall back to more seasonable levels in the 30s to bring in the New Year as strong west winds deliver a surge of colder air in the wake of the storm, but the mercury is expected to rebound into the lower 40s in 2020’s opening days continuing the above normal temperature trend.