Severe Weather Could Hit Area This Afternoon, Evening

The National Weather Service's Storm Prediction Center has now placed most of northern Illinois under a "moderate risk" category for severe weather. 

"A moderate risk indicates a potential for a greater concentration of severe thunderstorms than a slight risk, and in most situations, the storms associated with severe weather are more intense," according to the Storm Prediction Center.

A flash flood watch is also in effect for Cook County from 4 p.m. Wednesday until 4 a.m. on Thursday, according to the National Weather Service. Thunderstorms could produce heavy rain that could result in rapid flooding. 

The latest Hazardous Weather Outlook, issued at 4:08 a.m., shows that thunderstorms could produce strong tornadoes, damaging winds in excess of 75 miles per hour, hail to the size of baseballs and very heavy rainfall.

"The combination of strong instability and strengthening wind shear will be favorable for a significant severe weather outbreakfrom mid-afternoon through this evening," according to the National Weather Service's Hazardous Weather Outlook.

In his forecast summary, Accuweather.com Meteorologist Anthony Sagliani said there is the possibility that a derecho—"a widespread, long-lived wind storm"—could develop.

"These showers and thunderstorms produce wind damage over a large swath of land," said Sagliani.