N.IL Bow Echo/ Derecho- 7/11/11

This storm was one of those Summer phenomenon storms called a Derecho. These are very fast moving long lived lines of storms usually bowing outwards. They produce very high winds over the course of their trek usually causing widespread damage.

It was amazing watching this on radar as it was moving east at 60-70mph ! Its shape and velocity signatures were amazing..

When you looked outside you couldn't tell anything was out of the ordinary except it was

humid and warm. Suddenly though it got dark to the west and you could here thunder and within a couple minutes . Storm clouds raced east overhead . Winds quickly accelerated to what I estimated as 60mph here.Indeed in some areas they were likely higher in

the range of 65-75mph.

The hardest hit areas here were in east and North parts of RFD and Loves Park it seems where power poles were snapped or blown over !

Here my power went out right almost immediately. The lightning was quite strong but more so after the 'gust front passed well by. Lightning hit and split some big trees around here too.

Widespread damage was reported all over N.IL and Chicago with over 800k w/o power at one time.

I saw many pics of trees down and trees on cars.

Didn't see a lot of structure or impressive shelf cloud with this line myself but

storms still topped at about 60kft.

Power was out here for about 36 hours.


The line cell developed a very pronounced bow segment in EC Iowa..high winds were reported there

The line developed to more in a N-S line and was propagating more eastward now..

The time it got to NC IL a well developed Bow echo had developed

High Velocities were being indicated ..

Strong storms..echo tops around 60kft..

Some animations..storms were moving eastward at 60-70mph