After another long winter here in DeKalb where we broke some of those records you never want to touch (e.g., cold temperatures and a lot of snow!), we have finally seen the warmth return to the area for the most part. However, days like yesterday begin to put things in perspective. They are a sober reminder of how beautiful, yet ugly, nature can be. Throughout this week local (NWS Chicago) and national (SPC) had been hinting at the potential for severe thunderstorms in Northern Illinois on Thursday (4/9). As Thursday neared, I continually poo-pooed the chances of severe weather because of lackluster supercell and tornado ingredients. For the most part I was correct, and I wish I would have been 100% correct.
Throughout Thursday, whist preparing for my Ph.D. candidacy exam, I continually monitored visible satellite, surface observations, and radar from my office at NIU in DeKalb until about 4:30PM. I decided to head home around 4:45PM to keep a closer eye on radar in case I wanted to head out and see some convection. I noticed that the storm north of Davenport, IA was probably going to be the storm of the day because it was a heavy precipitation beast of a supercell. But, reports coming out on that storm were lackluster and chasers were having a hard time because of the Mississippi River pinning them in Iowa. I was still a bit down on the whole setup because the veered surface winds (usual here in No. IL resulting in mixed storm mode and linear segments). However, an isolated storm was able to form east of the larger, more dominant storm near the Quad Cities in Iowa. This isolated storm was supercellular in nature as it formed along the warm front and looked to be headed for Rockford at the time (
Radar loop). It ultimately did produce a tornado too. I knew with storm translational speeds being approximately 50mph, I had no chance of catching up to it. However, I did notice that a new storm was beginning to develop in its wake or outflow. I was hoping to head off this storm in western DeKalb county to see some "pretty" convection. As I began to move out, I noticed that the storm started taking on some supercellular characteristics. It illustrated really impressive gate-to-gate shear and a classic supercell radar signature. So, I headed west towards the storm hoping I could see something of interest. As I got closer and closer to the storm things got more and more interesting. I finally got a glimpse of its base about three miles north of the local community college here in DeKalb Co. What I noticed next was something surprising as well as terrifying. To my disbelief, there was a large wedge tornado on the ground and it was scouring the landscape! I jumped out of the the truck and began taking photos (wide-angle so the tornado was closer than it appears in the photos) of the beast while it was churning up the ground. The structure was great and I was thoroughly shocked at what I was seeing with my own eyes. I had to gather myself and get a plan, quick. The only option was to head north and try to keep up with the fast-moving storm.
As I started moving alongside of it, I noticed that it was steady-state (i.e., it was not varying at all). It looked like it could go forever. Some tornadoes just have a "special" look to them where they could go hundreds of miles. This one was one of those types from my vantage point. Unfortunately, it looked like it was creating damage as it was traversing the landscape. Early on I knew that this would be a killer tornado.... I would have bet on it. It looked like a violent and destructive monster. I could only hope that it would miss all of the farmsteads and communities peppered throughout DeKalb Co. Overall, I followed the tornado north through DeKalb Co. up to just west of Kirkland for about 30 minutes. It did not lift once and kept thrashing the ground like a spinning bolt. Little did I know, as I watched it cross right in front of me on Esmond Rd. it was hitting Fairdale, IL. Sadly, this resulted in two fatalities. Given the storm speed, I was unable to keep up with it safely, so I decided to wave it goodbye. At this point my nerves were shot from chasing a fast moving wedge tornado by myself (radar, phone, visual, dirt roads, etc. can be a lot to deal with while driving!). I headed home.
I noticed that as I pulled off headed east on hwy 72, there were blue and red lights about a mile to my west. I thought that it might just be a barn that was hit. Unfortunately, it was Fairdale, IL as I found out the next day. Later on that night, still wired, I was wondering how that type of storm was produced in this type of environment. I am confident after speaking with speaking with other meteorologists, that a storm that initially developed in the Morrison and Dixon area left behind a boundary that "fed" the tornadic storm I witnessed. In fact, this storm may have helped reinforce the warm front back southward at the surface. This could have caused the winds to back locally in Rochelle, leading to enhanced storm relative inflow that ultimately yielded in a long-lived, long-tracked, and violent tornado. A more complete and better postmortem analysis will hopefully reveal mine and other's suspicions.
Another opportunity was presented my way late Thursday night when I was placed on one of the NWS Chicago damage survey teams. This meant that I was able to tag-along, help out, and provide another set of eyes for the damage survey to be conducted that next day. As someone who had seen significant tornado damage first hand (2005 Evansville, IN EF3 tornado), I knew it would be a difficult thing to witness. However, I thought it would be an valuable experience and something from which I could benefit. And perhaps, my previous research on tornado damage intensity estimation techniques could provide some useful insight.
The team I was on included Gino Izzi (NWS Chicago WFO/NIU graduate), Walker Ashley (NIU professor/my adviser), and Victor Gensini (COD professor/former NIU grad. student). We were tasked with surveying the portion of the path from Rochelle, IL up to and including Fairdale, IL. This portion of the path was believed to be the most heavily hit as well. Overall, the tornado damage path began confirming what myself and other chasers witnessed. The tornado started out as a needle and gradually became a monster wedge. We focused a lot of our efforts on the community of Fairdale as it seemed to be the hardest hit or at least the most heavily impacted. Once we arrived in Fairdale we came upon utter devastation. Most of the community was a pile of rubble. Beginning our survey in the interior of Fairdale, we noticed that many of the homes that were impacted were older. This potentially means that they may not be as structurally sound as they could have been. Suspicions were confirmed when we noticed the homes that were the most heavily damaged were not bolted or fastened to their foundations. Many were simple cinder block based homes with the majority of the structure placed on top of the blocks with a few nails here and there. Unfortunately, this meant that we couldn't rate the tornado violent at this point because the damage indicators simply did not support greater wind speeds. As we walked around we did notice that many cars were lofted and rolled within the community which led to the potential for higher wind speeds.
As we moved back to the southwest portion of the path we knew there were a few structures that we wanted to survey near the intersection of route 251 and hwy 64. We arrived on these structures and immediately knew that this was the worst damage we had seen thus far. We noted that the homes in this area were newer/better built. They were bolted down to the foundation but swept fairly clean. Of note, there was a smart car and a dumpster that had been lofted, not rolled, 200 yards from its driveway. Based on our survey of this area and other teams' findings, it was decided that it was violent tornado damage at it's maximum intensity. This means winds greater than 166mph. It puts it in the 1-2% of all tornadoes with a recurrence interval of about 1 every 6 years in No. IL from 1950 to 2014 .
Overall, everyone we came across was upbeat and positive. People were bouncing back and praising the advanced warnings from the NWS. I was amazed at the excellent job done with the tornado warnings by the NWS Chicago WFO as well. I was even more amazed with the resilience of the people impacted by this monster. Sometimes events like these put things in perspective......
For more and
official information on the event please go to the NWS Chicago WFO webpage
HERE
Note: All photos herein are copyrighted by myself and the National Weather Service. Please email if interested in their use.
As the tornado was approaching I-39
Just as the tornado was hitting Fairdale, IL.
Homes at the corner of 251 and hwy 64
Fairdale, IL
West of Rochelle, IL
Fairdale, IL
No bolts. Just nails.
Corner of 251 and hwy 64. Note the bolting down to the foundation.
Vehicle that had be displaced 50 yards or so.
One of the most impressive displays. Smart Car was lofted 200 yards from the home.
Oh, and a steel dumpster was too.
Steel reinforced solid concrete silo that had not only been tumbled off its foundation but also twisted.
