Thursday, April 25, 2013

04/18/13 Eastern Illinois Shelf Cloud

Impressive looking shelf cloud begins
 to overtake me near Danville, IL 

On April 18th, I ventured out the door at 4:00am and began to head out of Peoria, IL east along I-74 to stay in front of a developing squall line. I had to dodge some serious flooding along the way that was ongoing across the local-area due to the 5"+ inches of rain that had occurred in a 24hr. period. By early morning, I found myself east of Champaign, IL near Danville, IL awaiting a Mesoscale Convective System (MCS) that was beginning to organize to my west. My location was characterized by only about 500J/kg of CAPE, 0-6km shear at 50kts, and a moist boundary layer with dew points near 65°F. I thought about chasing in Indiana later in the day, but my gut told me that destabilization would be a major issue to my east which ended up being the case for many chasers that made the trip to Indiana. Too much shear and meager instability due to the lack of surface heating. This day is what I call a "one and done" kind of chase. Basically, get in front of the MCS, take a few photos of the shelf cloud, and get a car wash. By mid-morning, I already called it a day knowing there wasn't much hope for severe storms in the afternoon as even this MCS was struggling to maintain itself after briefly going severe-warned. I headed back to Peoria, IL by noon, took a quick nap, and later documented the major flooding occurring in the area. I'll have another post regarding that event at a later date. Anyhow, I've added some worthy photos from this brief chase day below:

First view of the organizing shelf cloud at a wind farm...
Illinois landscape already showing signs 
of flooding as more rain is about to move in!
Shelf cloud moving-in with gusty southerly winds at
30mph at this point bringing in the warm air into the storm...
Outflow providing some picturesque photos
over the next hour!
Crazy lookin' sky providing some good photo-ops...
Another shot...
Looking north at a stormy landscape!
Whale's mouth moving overhead...
Contrast begins to change with the passing of
the shelf cloud thus providing some 
scary looking color's to the sky...
Good stuff!
I head back east along I-74 as I noticed a notch
 trying to develop along the line which actually had rotation!
I've added a YouTube video time-lapse illustrating
the rotation of this embedded supercell from
my GoPro cameras (above)
Looking south as the shelf cloud moves in once again!
Pretty cool shot here as this storm was at its strongest with
nice rotation in this notch. Good thing the GoPro's
were recording at this moment!
Amazing cloud formations right behind the
shelf cloud with some rotation (left) which was
a real treat to be able to observe after a long winter!
One more shot of the departing convection...
Saturated Illinois landscape from heavy rain as the
shelf cloud overtakes me for the last time on this day...
 
I've added a YouTube video of the chase day
 from my GoPro (above)

I'll update with another post regarding the major flooding at a later date that occurred over the last week when I get all caught up on some tasks. As far as my vacation goes I usually plan every year to head out the last week of May and first week of June. This year, I may be heading out later in June depending on this stubborn weather pattern and some new work obligations. I'll update accordingly.