I watched a batch of storms form in Northeast IA at work, thinking their path could take them over Chicago I left so I could go home and enjoy them. Upon my arrival home I saw that SPC upgraded us to a moderate risk as well as a PDS [particularly dangerous situation] severe thunderstorm watch. The text mentioned winds to 100mph possible. Needless to say I spent the next 2 hours glued to the PC tracking this clusters every move.

 

A radar grab as the complex, now a healthy bow echo system races towards the city.

 

 

A couple of interesting things to note here.

 

The tornado warning box in white, goes right over my house. The siren by my house didn't sound but I could hear the ones to the south going. It was the first time I heard the sirens from home since I was probably 13. They have gone off before, but I was always out chasing somewhere else and missed them.

 

Second is the insane amount of lightning with this storm. Each white lightning bolt indicated more than 10 lightning strokes a minute, this would provide constant flashing and thunder once it hit. I was pretty excited.

 

This was the storm at this point, I wanted to get the sirens going off.

 

 

I started thinking about August 23rd of last year, this was a very similar type of storm complex. Perhaps a new August tradition is being born here in the city? I doubt it, but its fun to hope. Anyways, the warnings continued and the storm finally arrived with full force. I tried to snap lightning shots and shoot video but sideways rain coming through the window greatly hindered my efforts.

 

In the video an intense gust of wind will cause power lines to come down and the neighborhood to lose power. My house for some reason stayed with power, but as you will see it flickered a few times as the 60mph winds started blowing stuff off my shelf.

 

Once I couldn't film anymore I decided to attempt the lightning shots again and was able to get a pretty decent one.

 

 

 

As well as a few others. Unfortunately the best photo above is somehow damaged digitally and I cannot add my watermark nor enlarge it at a good quality.

 

 

 

 

 

 

 

 

Once things calmed down a bit I stepped out to view damage. Just some limbs down but nothing too significant.

 

 

 

After a short drive this was pretty much the scene around my area. Sections of the city to the south were hit much harder. It turns out what is called a mesovorticy was embedded in the line. To put it simple these are areas of rotation higher up in the storm that can sometimes enhance straight line wind damage. These are what prompted the tornado warnings. They can also cause spinup tornadoes along the leading edge of the bow complex. This was the case as it reached Griffith, Indiana which received EF-2 level damage. 

 

Later that night, a second round of storms developed over the city with similar results. Instability in the area was off the charts, over 8,000 j/kg CAPE! To put it into perspective...1000 is considered to be the severe threshold, and the most violent supercells that form in the plains can get going on 3,000. So to have CAPE of that intensity around here was insane, and the storms that blew up shortly after this complex passed were also great lightning producers, at this point I enjoyed a long night laying in bed and watching/listening.

 

Here is some info from the SPC and NWS.

 

SPC storm reports: