Bright sunshine allowed temperatures to rebound across portions of the Chicago area Friday. Afternoon readings peaked in the mid-70s from Rockford, through Aurora and Kankakee. Meanwhile, east winds held lakeside areas in the upper 50s. Warmer air is forecast to become established across the entire area over the weekend, with readings reaching the low 80s on Memorial Day. Satellite imagery late Friday evening indicated a storm center over the southwestern U.S., just south of Las Vegas. This system is to influence Chicago's weather much of the upcoming week. Strong south-to-southwest jet stream winds are forecast to shift east in coming days, spreading tropical air across the Midwest. The city may experience a string of 80-degree days beginning Monday.