An unexpected super soaker of a thunderstorm moved through Knox County Sunday night, dropping as much as eight inches of rainfall in the county’s northeastern-most points.
Knox County Emergency Management officials, first-responders and even meteorologists with the National Weather Service in Indianapolis watched with surprise Sunday night as a second cell formed behind one that brought a severe storm through Knox County.
“We were not expecting that, and it developed so quick,” said John Streeter with Knox County EMA. “Something caused that to intensify and build, and we had some really heavy storm cells move through, ones with wind, lightening and a lot of rain.”
Matt Eckhoff, a meteorologist with the NWS, said rainfall totaling upwards of 8 inches is quite rare.
“Rain of that magnitude, you’d have to wait a couple of decades to see it again,” he said.
The NWS issued a severe storm warning for Knox County just after 7:30 p.m., and meteorologists said that storm did bring with it winds in excess of 60 mph, toppling trees, bringing down limbs and leaving thousands without power.
Most everyone breathed a sigh of relief once that system passed, but several cells formed rapidly behind it.
Vincennes saw about four inches of rain, according to officials with Vincennes Water Utilities, but areas to the north saw upwards of 6-8 inches.
“Radar estimated between 5-7 inches up there with a few spots seeing close to 8,” Eckhoff said.
As a result, the NWS began issuing flash flood warnings, Eckhoff said.
“When the ground is very dry, hard and cracked, dense like that, and you get a downpour like that, the absorption rate is slow,” he said. “Storm water is way more likely to run off and collect in low-lying areas.”
And collect, it did.
Multiple county roads saw high water; several remain closed to motorists. As such, Knox County remained under a travel advisory Monday morning.
“We’ve had a few culverts wash out that will have to be replaced,” said county highway superintendent Benji Boyd. “We’ve had roads wash out to the extent that we will have to repair them.
“Of course we are still assessing everything,” he said Monday morning. ”We could find more out there. Already we have our eye on some bridges; while there doesn’t seem to be any structural damage, it will take several truck loads of rip rap.”
Streeter said the storm cells had a lot of lightening as well, and fire crews were kept busy most of the night responding to lightening strikes. There were not, however, any major fires.
There were a handful of water rescues, both from people who found themselves stranded suddenly as the storms formed as well as those who mistakenly entered flood waters.
Some homeowners, too, had to be helped from their homes as flood waters threatened.
“We had tree limbs down, a lot of lightening, fires. We had water in areas we don’t usually have water because it’s been so dry,” Streeter said. “We had flooding where we don’t normally have flooding.
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“And we had water rescues where individuals had to be evacuated out of their house or structure. But we had no injuries, which is always a plus.”
At the height of the storm, several roads were closed, including Indiana 550 north of Wheatland, Overhad Road, Bicknell Road, Transformer Road, Moody Road and Pine Bluff Road; several photos circulated on social media of a wash out there.
Inside the city, however, Kirk Bouchie, general manager of Vincennes Water Utilities, said roads fared well.
“We had four inches of rain in most of our gauges,” he said. “But we didn’t have any major problems, and I’m not aware of any issues that have persisted.
“But as we always remind people, when these kind of rain events happen, you can’t afford to design a system to handle huge rains like that immediately.
“Sometimes things will flood for a short period of time and go down. That’s the sign of a good working drainage system.”
Knox County Commission President Kellie Streeter was following developments closely Sunday night and was out inspecting damage Monday morning.
Repairs, she said, will take time.
“Besides the power outages and dozens of trees that have had to be removed from roads and high water on dozens of roads, the damage from the wash outs is extensive,” she said. “This is going to be a long-term fix.
“Water is so powerful,” she said. “When people think of thunderstorms they think of tornados and wind, but being in a low-lying river region, extreme water becomes just as dangerous.”
When the updated U.S. Drought Monitor was released on Monday, Knox County was still listed as abnormally dry; that’s not likely to be the case next week, Eckhoff said.
“Those dry conditions are very likely over,” he said.
Before Sunday’s rain, Knox County was experiencing a departure of a tenth of an inch from July’s average rainfall, which is usually 3.5 inches.
“But most areas of Knox County are now at 7.5 inches,” he said.
And more is likely on the way, Eckhoff added.
After another risk of severe weather Monday night, rain chances remain in the forecast for Wednesday and Thursday, just likely not as widespread, he said.
Temperatures, too, will be mild, with highs through the work week right about 80 degrees.
“Then finally you’ll see that wet weather taper off by Friday morning when dry weather returns for the weekend,” he said.