CHICAGO — Mainly sunny Thursday with humid conditions. Cooler lakeside, Winds: W 0-5. High: 88/83.

FRIDAY, AUGUST 4
HIGH: 86 LOW: 68
Sunshine and mixed cottony fair weather cumulus clouds. Seasonably warm inland, cooler breezes along the lake. Slight chance of an isolated PM showers/thunderstorms far south. High: 86/79 beaches and lakeshore.
FRIDAY NIGHT: Partly cloudy, warm, continued moderately humid. Low: 68.

SATURDAY, AUGUST 5
HIGH: 83 LOW: 68
Partly sunny, warm, moderate humidity continues. 20% chance of a shower or thunderstorm late in the day, but most areas should remain dry. High: 83/78 lakeshore and beaches.

SUNDAY, AUGUST 6
HIGH: 86 LOW: 66
Partly sunny, warm, noticeably more humid. Severe thunderstorms threaten in the afternoon and evening. The strongest storms are capable of damaging wind gusts, large hail, heavy downpours and isolated tornadoes. High: 86.