It will seem a lot more like autumn than summer by the end of the week as weather
more typical of mid-October arrives on the scene. Sunday's record-tying highs in the
middle 80s will be long-gone, replaced by Saturday morning lows in the 30s that could
bring frost and even freezing conditions to areas away from Lake Michigan. The
downhill temperature trend will begin slowly on Tuesday and Wednesday as
temperatures remain in the 60s. Cooling gathers steam later in the week as highs fail to
break 60 from Thursday through Saturday.
Some light showers will accompany the first surge of cooler air early Tuesday, but a
more significant shot of rain is expected to move in Wednesday before a stronger
intrusion of colder air.
NANA FADES -- OMAR LIKELY TO BECOME A NAMED STORM TUESDAY
Tropical Storm Nana has weakened to a depression and will dissipate in the open
Atlantic later this week. Meanwhile, another depression gaining strength south of
Puerto Rico should become the season's 15th named storm, Omar, Tuesday. The
system's heavy rains already produced flash flooding in Puerto Rico on Monday.
--By Steve Kahn, WGN Weather Center Meteorologist
