Update: TORNADO WATCH issued for the Stateline

5:00pm UPDATE: A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR OGLE COUNTY UNTIL 5:15PM. The storm currently over Byron, IL is moving to the northeast at 40 mph and is capable of producing 60 mph wind gusts. If you're in the area of this storm, seek shelter immediately. It has had a history of producing a 60 mph earlier near Sterling.  

UPDATE: TORNADO WARNING CANCELED FOR JO DAVIESS COUNTY

3:30pm UPDATE: A TORNADO WARNING has been issued for north-central Jo Daviess County until 4pm. A severe storm located over/near Galena is capable of producing a tornado, moving north at 40 mph. Those in the impact area: Galena and Council Hill.

UPDATE: A TORNADO WATCH has been issued for all of our northern Illinois and southern Wisconsin counties until 8pm. Rapid development of thunderstorms is likely by mid-afternoon, some posing the risk to turn severe. Make sure you have a way to receive these watches and warnings as they are issued throughout the afternoon.

PREVIOUS DISCUSSION: 

Thunderstorms from Saturday morning have cleared rather quickly, giving way to a partly sunny sky Saturday afternoon. Temperatures have warmed into the mid and upper 60s across northern Illinois on the heels of a gusty southeast wind.

As a warm front nears closer through the afternoon from the south, and a cold front from the east, thunderstorms are likely to develop quickly within the next couple of hours across western Illinois. With the clearing that has taken place over the last couple of hours, instability has developed and will continue to slowly rise through the afternoon.

This will help feed some of the thunderstorms for late this afternoon, along with the strong winds in the jet stream. Storms are expected to turn severe, with all hazards of severe weather possible; hail, wind and tornadoes. 

The initial development of the storms will likely be individual storm cells, merging into more of a cluster, or line of storms, once they move east of I-39. It's the individual storms that we will need to keep an eye on for any rotation that could pose a tornado risk through mid-afternoon.

It's likely that a tornado watch will be issued within the next hour for northern Illinois and southern Wisconsin with the anticipation of thunderstorms to develop quickly through the afternoon.