Lakeshore cooling persists a second day Saturday. Friday produced a temperature spread of up to 30-degrees between Chicago area beaches and the warmest inland locations.

While Kenosha and Highland Park, on the receiving end of easterly winds coming off chilly lake waters, ended up on the low end of the thermal ledger Friday with highs of 56 and 57-degrees, both Kankakee and DeKalb were warm, posting 85 and 82-degree peak readings respectively.

Saturday highs will repeat that trend with shoreline and beach temperatures holding to the low 60s while inland locations, head toward their warmest weekend temperatures since last September (37 weeks ago). Highs there will reach the mid 70s while near 80-degree readings are likely at the warmest south suburban observation sites.

80s return to the city Sunday, Monday and Tuesday after 2 day absence

Strengthening south to southeast winds return much of the city and inland areas to the 80s Sunday—the beginning of a fresh three-day string of 80s likely to run through Tuesday. It's conceivable a fourth 80-degree high may occur Wednesday.

80-degree or warmer daytime highs Sunday, Monday and Tuesday would mark the 6th, 7th and 8th time this year that temperatures have moved into the 80s.

Isolated thunderstorms unleash Friday’s heaviest downpours south of the city; spotty storm development ahead Saturday and Sunday

Isolated thunderstorms produced by towering cumulonimbus clouds (i.e. thunderheads), which reached heights up to 46,000 ft. Friday according to Doppler radar scans, are likely to re-develop in scattered fashion both Saturday and Sunday.

Though only a fraction of the full Chicago area may see these storms, the moist environment in which they’re developing could produce brief downpours.

Predicted warmth comes as meteorological spring 2013—currently the coolest in 17 years—enters its final two weeks

The predicted weekend warmth comes as the coolest meteorological spring season of the past 17 years moves into its final two weeks.

Since March 1—the start of meteorological spring—Chicago’s temperature has averaged 43.7-degrees.  That’s a reading 1.6-degrees below the long term average and 10.4-degrees cooler than the same period a year ago.

"Trying" pollen season produces a 13th consecutive report of “high” tree pollen values Friday

This pollen season has been a miserable one for far too many area allergy sufferers.  Pollen counts are generated Monday through Friday. Friday marked the 13th consecutive report in which the tree pollen value taken by Dr. Joseph Leija and distributed by Loyola-Gottlieb Memorial Hospital was categorized as “high”.

Most humid weather so far this year to build in during the days ahead; surging moisture levels to fuel t-storm clusters

The average of a suite of 7-day computer model rainfall estimates through next Friday and centered on Chicago has jumped to 1.80”. Such an average is the product of more than 40 individual computer-generated predictions. Those forecasts included rainfall estimates ranging from as little as 0.93” to as much as 4”.

Mid-U.S severe weather potential on the rise; Chicago area at risk, particularly Monday and Tuesday

Since 2000, May has ranked as the top tornado-producing month across the greater Chicago area—a region which includes 17 counties from southern Wisconsin to northern Illinois and northern Indiana.

Of the 78 twisters which have been logged since the start of the 21st century, 26 of them—33% have occurred in March.  That’s why it’s little surprise the area may be headed for some challenging thunderstorm clusters capable of severe weather production in the days ahead.  This is particularly true of thunderstorms predicted to “bubble-up” into a vigorous overhead spring jet stream Monday and Tuesday next week.

Waves of severe weather are predicted to sweep the Plains Saturday then extend eastward into the Midwest Sunday.

Chicago is close enough to the area of potential severe weather that any storms which develop later Sunday into Sunday night will have to be monitored.  But, it’s the Monday, Tuesday and possibly Wednesday periods which appear likely to warrant the greatest attention.