April 28, 2014 Bureau County Storm Chase
Location: Bureau County, IL
Partner: My Dad
Tornadoes: 0
Highest Wind Gust: 29.1 MPH (measured)
Largest Hailstone: 0.75" (Penny-sized)
Accomplishment: 1st April chase!
Beginning of the Chase Day...
This "chase" actually began several days ahead of time, as I watched the weather models send a large, strengthening, and slow-moving upper level low across the United States. With it came strong upper level winds on top of a very warm and unstable airmass. This would likely spell a tornado outbreak from Texas and Oklahoma to the East Coast. However, I was watching the warm front since it would make an appearance in our area. Some decent wind shear/close proximity to the low and somewhat unstable air would likely bring low-topped supercells and maybe even a few tornadoes to northwestern and west-central Illinois that Monday. Right after school Monday (since I was trapped there with no Internet access), I went home to study the radar and pick a storm to chase. My Dad got off of work at 3:30 and we were out the door by 4:00.
The Chase...
My targeted storm was a weak supercell that had an okay-looking hook echo on it, meaning there was some rotation. It crossed I-80 in eastern Henry County. The storm wasn't tornado warned, but if it strengthened, I wanted to be there. We raced
to Princeton, then northward to Ohio, IL before realizing: a) we weren't going to catch up with it, and b) it was weakening, and wasn't worth chasing anyway.
I then noticed some wannabe supercells over Putnam and southern LaSalle counties moving north, so we traveled east to LaMoille to catch them if they intensified. When they didn't, and after we wasted MORE gas, we decided to go back to Princeton, where we were half an hour ago. However, I didn't head back there without reason. A line of severe storms was moving in from west-central Illinois and the Quad Cities area. Severe Thunderstorm Warnings were issued for Bureau, Putnam, Knox, Peoria, and Marshall Counties for 60-70 MPH wind gusts and quarter-sized hail.
We got into position for where the most intense portion of the line seemed to be headed (for Bureau County anyway), which happened to be about halfway between Princeton and Wyanet. However, the most intense portion of the line shifted east only a few minutes before it was expected to move in, so we were forced to gamble and drive east about 6 miles through Princeton without having the storms impact us. After encountering a frustratingly long wait at a red stoplight, we continued east on Route 6 near I-180 and turned south on a country road with a clear view of our storm.
A greenish tinted shelf cloud and heavy rain/hail shaft were a spectacular sight to behold. I deployed our anemometer probe to measure wind speeds as the storms rolled over. Cloud to ground lightning was striking very closely to our location. When the first rain/hail curtains were moving in, they behaved like water poured on a flat surface; they hit the ground and then spread out. I mistook the rain curtains for a gustnado at first, but finally indentified them. A few seconds later, the rain- and hail- engulfed us.
The hail was mostly pea to dime sized, but there were a few penny sized stones as well. The winds were gusting to about 30 MPH, and combined with the extreme precipitation rates, visibility was nearly zero. I filmed through the storm, with the window open, causing water on the lens to mess with the camera's ability to focus. The audio became muffled because water got into the speaker (don't worry, it's fine now). I was SOAKED.
Once the storms passed, we attempted to catch back up to them. We managed to catch the backside and witnessed some more hail, but decided to head back home since it wasn't worth chasing these another 20 miles.
