This weekend high temperatures on Saturday and Sunday will approach the 90-degree mark – making this the warmest weekend since last July 20-21.
One more day Saturday with sunny skies, low humidity and easterly winds, then the Canadian high pressure will move east. Sunday southerly winds will pull the warm humid air originating in the Gulf of Mexico up the Mississippi Valley into Illinois. Dew points will increase into the 60s here by Sunday afternoon and during peak heating hours readings will approach the 90-degree mark for the second straight day –this time triggering the development of building cumulus clouds. Scattered showers and thunderstorms are likely to develop over northeast Illinois, southeast Wisconsin and northwest Indiana during afternoon into the evening hours.
The warm humid unstable air will rest over our area Monday, and the approach of a cold front from the west will give impetus to another outbreak of thunderstorms with strong to severe storms possible later in the day and overnight. Numerous heavy downpours could trigger flood problems along small streams, viaducts, and low-lying or poorly drained areas.