Sunday, July 28, 2013

06/24/13 Illinois Derecho

A derecho races across Iowa and takes aim on central Illinois
north of Peoria, IL 

On June 24th, I was working till 5:00pm in Peoria, IL. I kept tabs on the weather situation however through most of the day at work knowing I might be out in the evening. Severe storms tracked across much of Iowa during the morning-hours and would enter an unstable environment later in the afternoon across Illinois. The area out ahead of this developing derecho was characterized by 3,500J/kg of CAPE, 0-6km shear increasing to 30kts, and a moist boundary-layer once again with dew points near 72°F. Luckily, for Peoria, IL the apex of the derecho went to the north of town producing widespread wind-damage across northern Illinois. Once the shelf cloud passed I called it an evening since this derecho was screaming east at 60mph! You couldn't chase that thing if you tried too. Frankly, you'd be the one being chased in this instance. Anyhow, I've added a few photos and a short time-lapse of the shelf cloud that accompanied the derecho below:

First view of the grungy looking shelf cloud as it progresses
into Peoria, IL 
This derecho did produce some confirmed tornadoes in
Iowa and Illinois...
Here she comes with cool outflow blowin' in from the west!
The whale's mouth rolls in (looking east)...
Quite a photogenic whale's mouth on this derecho!
Gusty winds move-in as well as the rain-curtains...
I've added a short YouTube time-lapse (above)

That wraps up this day. I think I had about 15 minutes of photography before this derecho was long gone racing east. Crazy! I did head out to chase after work on June 25th as well. I'll update with that post in the coming days.