Sunday, August 29, 2010

Plainfield, Illinois F5 Tornado 20th Anniversary

The Plainfield tornado is without a doubt the most significant tornado to strike near home. That incredible F5 tornado is not only the lone F5 to strike the greater Chicagoland area but it is also the only F5 to strike anywhere in the country during the month of August. Unfortunately 29 people lost their lives making it one of the deadliest tornadoes to strike this region. It is a classic example of an unseen event as the day called for potential severe thunderstorms but the thought of tornadoes never crossed anyones mind. The tornado struck without a watch or a warning. It was spawned from an incredible HP monster and to this day there are no known photographs or video of it which makes it somewhat of a mysterious monster.

That day was August 28th, 1990. I was only 7 years old at the time but do have several vivid memories from that day. I remember the evil green sky and the newspaper photograph of a demolished church. Plainfield is still a good 20 miles from my home, but close enough.

What caused such a violent storm? Weather observations weren't as in depth as they are today, but there was obviously an extreme amount of instability in the atmosphere, temperatures had soared into the mid 90s with dewpoints into the upper 70s, that alone provides an extreme amount of energy. A cold front was sliding south through the area but the wind field wasn't anything that screamed weak tornadoes let alone an F5, and this perhaps is was fascinates modern day forecasters to analyze this day using the vast network of new and improved forecasting techniques that have come since then. The unusual direction the tornado traveled [northwest to southeast] is yet another piece of the overall unique puzzle pieces that came together this day. The storm had to have some sort of boundary interaction and my guess is the odd movement of the storm against the very unstable surface flow coming from the opposite direction really enhanced its srh [storm relative helicity.] One can only speculate though until another similar event occurs and is further analyzed.

Could another event like this happen? Absolutely. The advantage we have now is a better understanding of weather, better radar technology along with more active spotters and chasers out there. It is hard to believe that such a significant event could happen again without warning.

The NWS put out a great pdf article of the event which includes video at the end of the storm before it produced the tornado. Its quite an eery video showing a mean green HP machine sporting a violent wall cloud and some insane rising motion. That article can be seen here:

I decided to pay a visit to the memorial to pay my respects to those who lost their lives in this underrated hazard that exists in our area. The memorial itself is quite a site, it stands taller than me [I am 6'3"] and is lazer carved from beautiful black granite.

1 comment:

Peter said...

I live a mere 3 miles from the memorial and I grew up not far away in Romeoville. Every day I drive past that memorial knowing that people died. This is why storm chasing not only is a hobby, but also a duty to serve all of the people who have given their lives because of little to no warning time.