Storm threat continues this afternoon

Strong thunderstorms moved through N. IL and S. WI late Thursday afternoon and evening.  Numerous wind damage reports were received from Whiteside County up through Rock County.  Tornado sirens were sounded in Ogle County and heard from Mt. Morris, Oregon and Byron as a strong thunderstorms rolled through the county.  This came after a tornado had been reported near Prophetstown in Whiteside County.  While there were no official reports of a tornado there were several damage reports stretching from Lowden State Park up to Stillman Valley.  The likely cause for sounding the tornado sirens in Ogle County were possibly due to a gustnado forming along the leading edge of the storms.  A gustnado is different from a tornado in the fact that it forms on the gust front of a thunderstorm (or showers) and visible from a shelf cloud and not associated with a wall cloud like a tornado is.  These can sometimes be mistaken for tornadoes, but if you monitor it closely you'll notice that it's usually forming ahead of the storm and not under.

The threat for strong to severe storms continues this afternoon, but the storms from Thursday have kind of 'worked over' the atmosphere this morning.  We're not starting off with as much sunshine as we did yesterday so the instability within the atmosphere isn't expected to quickly rise.  However, there is going to be a little more support in the atmosphere from the jet stream as winds move in from Missouri and Iowa and up through the Great Lakes.  This will likely help drive thunderstorms into N. IL later today.  Ongoing showers and storms in Missouri will be watched for possible develop closer to home this afternoon.  There are currently severe thunderstorms along the

southern edge of the storm complex in Missouri but those are moving southeast and will not impact us.  The northern and leading edge of the storm complex is what may impact us this afternoon; especially if it intensifies some through the morning.  At the moment heavy rain is just falling in southeast Iowa - no lightning has been detected.

The Storm Prediction Center continues to highlight N. IL and S. WI under a slight risk for severe storms this afternoon.  If storms were to form damaging wind gusts would likely be the main threat.  It's possible the strongest storms may slide just to the south of the Stateline so be sure to continue to check the blog through the afternoon as we'll continue to provide updates.