Chicagoans were treated to the warmest temps Thursday of the past 6 day—with a 66 at O’Hare marking at 14 degrees increase over Wednesday’s 52. Easterly lake breezes off the 46-deg lake waters held shoreline and beach temps to the 50s.

Downstate clouds and showers are northbound—but to a rendezvous with a portion of the Chicago area by morning and into the early or mid afternoon hours Friday. Modeling suggests Chicago proper has the highest chance for some showers in the 6 p.m. to 2 or 3 p.m. Friday time frame.

More important is the spin-up of a significant and slow moving upper air low pressure which will be home to a pool of chilly, unstable air aloft beginning this weekend and carrying over into the opening days of next week. Such weather systems associate themselves with clouds and instability showers—and this one will be no different.

While rains won’t be continuous, the prospect for showers roaming the area is to be elevated Saturday through Tuesday—and the presence of sun-blocking clouds will produce cooling of temps. Highs will drop from the low 60s Saturday to 51 Sunday, 47 Monday and 53 Tuesday—readings well below the normal highs in the mid 60s this time of year.

While a modest temp rebound occurs the back half of next week with the emergence of some sun, the real warming may wait until the week that follows when forecast trends suggest (finally) a return to above normal temps—which is likely to mean some 70 degrees and high daytime temps.

Until then, this week is to post a temp nearly 8 degrees below normal and next week is to come in nearly 7 degrees below normal overall.


TONIGHT: Clouding over, not as cold. Some rain showers possible in the pre-dawn hours—first appearing in the southern suburbs. Low 42.

FRIDAY: Cloudy with showers over portions of the Chicago area into early afternoon. Breaks in the clouds once showers exit later in the day. High 57—but only upper 40s along Lake Michigan.

FRIDAY NIGHT: Partly cloudy. Near seasonable cool temps. Low 42.

SATURDAY: Clouds dominate, becoming breezy from the west/northwest. Chance of some scattered showers likely to have impacted 50 to 60% of the area before the day is out. High 61.

SUNDAY, MONDAY AND TUESDAY: Extensive cloudiness, blustery and unseasonably cool for the season with showery spells. A few showers may include small hailstones Sunday and Monday. High Sunday 51. Monday’s high 47. High Tuesday 53.

WEDNESDAY: Partly sunny, milder. High 58.