'You couldn't see a thing': Nighttime tornadoes are rare but more dangerous

Of the more than 220 tornadoes that have touched down in the six-county Chicago area since 1950, just 17 have happened overnight like the one that tore through parts of Naperville, Darien and Woodridge a week ago.

While rare, nighttime tornadoes often pose a greater risk to those in the twister's path and to emergency workers responding to the devastation left in its wake.

"First off, you have people in bed who may not be alert to what's going on," said Todd Kluber, a meteorologist at the National Weather Service's office in Romeoville. "And then you can't see any of the hazards at night, definitely."

Since 1950, less than 9% of the 2,898 tornadoes documented by the National Oceanic and Atmospheric Administration that originated in Illinois happened between 10 p.m. and 5 a.m., records show. Those nighttime twisters, including the one last Sunday, have resulted in 23 deaths and 278 injuries.

Mike Bardou, a National Weather Service warning coordination meteorologist, said a lot can happen between where a tornado starts and where it ends.

"It's very common for a tornado's strength to waver along its path," he said. "Like the one from Sunday, a lot of the damage was in the EF2 range and one pocket where we placed the EF3 rating."

Experts advise people to station a NOAA weather radio in bedrooms for these types of events. The radio alerts are almost simultaneous to when the National Weather Service issues a warning. Phone alerts might take several seconds or even minutes to sound. And tornado sirens aren't meant to be heard indoors. The weather radios can also be used without a power source.

"I was sleeping and my phone woke me up and scared me to death," said Megan DuPass, a Woodridge resident whose home was one of roughly 100 in the village severely damaged by the tornado that struck just after 11 p.m. "My heart was racing and just as I was asking my husband what the noise was, we saw on the TV a tornado was in Naperville and they literally said it was headed to Woodridge."

Just as they gathered their three young children, the power in their home went out, making the trek from the upstairs bedrooms to the basement even more treacherous.

"You couldn't see a thing. There was no light," DuPass said. "A minute or two after we all made it into the basement was when it hit us. We didn't even know it was supposed to rain. When these things happen in the daytime, you can see it coming and kind of prepare for it. But we went to bed and never thought something like this would happen."

The darkness also hampers the emergency response.

"The hazard of dealing with a tornado, or any sort of operation we deal with, at night is obviously visibility," said Woodridge-Lisle Fire Protection District Chief Keith Krestan. "In this event, you had no power anywhere. It was dark, really dark, and there were hazards everywhere, hazards you know are there but can't necessarily see."

He said the last thing any first responder wants to happen is to become a casualty of the storm themselves.

"You do not want to add to the situation by getting yourself injured," he said.

Without light, the rescue efforts automatically are slowed and become even more methodical to avoid injury to emergency workers or those they are trying to help to safety.

Responding to a tornado was a first for many emergency workers last Sunday, but responding to one at night was probably a first for most of them, experts said.

Tornadoes happen more frequently in the daytime because the sun's energy often fuels them, Kluber said.

"The sun turns up the atmosphere like a boiling pot of water," Kluber said. "Without the sun out, it's harder to maintain that kind of energy, but it still happens sometimes like it did Sunday."

But even when the nighttime tornadoes occur, they are far less likely to be as powerful as the daytime counterparts because of the lack of sun. Less than a dozen of the nighttime tornadoes in Illinois have ever been categorized as an EF3 or higher, NOAA data shows.

"This one acted way out of normalcy," said Dan Casper, a meteorologist who operates a Facebook page called the Manhattan Weather Channel that focuses on Will County's severe weather and broadcasts radar analysis during major storms. "This storm wasn't expected to drop an F3."

But Casper said almost as soon as he went live on Facebook, the action on the radar started heating up.

"We started broadcasting that night around 8 p.m. and we could see the line consolidating and creating winds of between 70 mph and 90 mph, and that alone should give you concern," he said.

Casper said he was advising viewers to seek shelter well before a tornado warning was issued because "it's better to be safe than sorry, and I saw there was a threat."

Will County is one of the state's most fertile counties for breeding tornadoes.

Only downstate McLean and Sangamon counties, with 110 and 81 tornadoes respectively, have had more twisters begin there than Will County.

A 1990 tornado that ripped through Will County and killed 29 people in Plainfield remains the only F5 to originate in the Chicago area.

Will County, one of the largest counties in the state, has spawned the most tornadoes of any Chicago area county with 74 documented by NOAA. Yet, only four have happened at nighttime.

By comparison, Cook County has experienced 58 tornadoes since 1950, four of which happened overnight, according to NOAA records. DuPage County has had 28 tornadoes originate there, but just one between 10 p.m. and 5 a.m. before last Sunday.

Of Kane County's 23 tornadoes over the past 71 years, just two were at nighttime. McHenry County has seen 20 tornadoes start there, two at night. In Lake County, 19 tornadoes have originated there, with four coming at night.