The weather forecast for Will County called for thunderstorms on Aug. 28, 1990. No advanced warnings or watches were issued for the possibility of a tornado.

Then, an F5 twister tore into parts of Oswego, Crest Hill, Joliet and Plainfield, completely obscured by rain.

The storm killed 29 people and injured 353 more over a 16-mile stretch. It demolished Plainfield High School, a church and large portions of the town. The storm leveled homes and a large apartment complex in Crest Hill, and caused damage to homes and businesses on Joliet’s west side.

This tornado remains the only F5-rated tornado – the strongest storm rating by the National Weather Service – documented in the U.S. during the month of August.

“There have been a lot of changes in the last 35 years,” said Mike Bardou, a warning coordination meteorologist at the Chicago office of the NWS in Romeoville. “A lot of those are due to advancements in technology, but there’s also been a greater emphasis put on creating a network of storm spotters.”

Storm spotters are ordinary “civilians” who are trained to observe weather issues and report them to local weather services, as well as noting and calling in damage in the immediate aftermath of storms.

“There weren’t any organized or active storm spotter groups in the Will County area in the 1990s,” Bardou said. “After that tornado, DuPage County partnered with us and the College of DuPage and created the DuPage Advanced Severe Weather Seminar to train folks in the public on how to be storm spotters and to raise awareness of emergency weather preparedness. They trained hundreds of people through that program.”

‘A unique’ storm

On the day of the Plainfield tornado, the National Weather Service only issued a severe thunderstorm warning in the minutes leading up to the storm. It wasn’t until after the majority of the damage had been done that a tornado watch was issued.

In a 25th anniversary retrospective piece on the storm, WGN meteorologist Tom Skilling referred to the Plainfield tornado as “a unique piece of meteorology” because of when and how it hit.

The tornado came through from the northwest, which is against the typical pattern for such storms, and was off-season, as 80% of Illinois tornadoes occur between April 1 and June 30. Additionally, despite its massive path of destruction, the funnel cloud itself was never photographed or caught on video, partially because it was “rain wrapped” by the storm front, creating severe visibility problems.

“That particular tornado, there are still no known photos or images of the storm itself,” Bardou said. “Even 35 years ago without smartphones, that was unusual. For a storm of that size to have not been recorded by anyone is amazing.”

Technology and communication

The lack of cellphones contributed to more issues than just a lack of photographs. Today, NWS weather alerts often trigger messages on cellphones, and it is easier for civilians to call in unusual conditions.

“Communication has improved immensely,” Bardou said. “Back then, they only had sirens, TV and radio to put out warnings. The internet, social media and smartphones make it a lot easier to reach folks and to pinpoint certain impacted areas.”

Bardou also noted that the few storm spotters who were trained had to rely on landlines and fax machines to communicate with weather centers, and there were very few automatic sensors to send reports in to meteorologists.

“It’s much easier to document things and get information to forecasters now so they can make better decisions,” Bardou said. “There’s tons more data available to us now, as well as an extra 35 years of information and research on tornadoes. In 1990, we had about 45 years worth of data on tornadoes. Now, we’ve almost doubled that.”

Of course, the largest technological improvement for weather forecasters came less than two years after the tornado with the introduction of doppler radar systems, which were in the process of being developed in 1990.

Had the systems been in use at the time, instead of the outdated single-pole radar, the storm might have been more visible to forecasters.

“There are constantly upgrades happening with technology,” Bardou said. “The data and image quality we have coming in now is much better than what existed 35 years ago.”

While improved technology and human networks have made it easier to give people warnings about incoming severe weather, Bardou notes that it is “always important to have a backup.”

He advises people to pay attention and to keep devices such as all weather radios – which activate alarms when the NWS issues warnings – in their homes.

Bardou said that the improved radar and ground reports, combined with observed atmospheric conditions, give the NWS the information it needs to issue watches and warnings. Today, he said, if two of those three indicators show signs of problems, a warning is issued.

“We haven’t had another storm like Plainfield in this area since 1990, but these things do continue to happen, so people need to be aware,” Bardou said. “We always like to emphasize the importance of preparedness so you know what to do if a warning or severe weather impacts you.”