It’s not often I get to go out and survey storm damage. I’m usually in a studio under bright lights. When storms hit today, the newsroom dispatched me into the field. Initially, I saw tree damage along Pausch Road near Leesburg, Ohio:

This photo was taken looking northeast and all of the downed trees are pointing towards the southeast, where radar suggested the winds from the storm were pointing to. In nearly the same spot and facing the opposite direction, damage to barns suggested a northwest wind when it occurred. There was siding in the field from the leftmost barn pictures just southeast of the barn:

With all of the damage fanned out in a uniform direction, this suggested straight-line winds caused this damage.

Shortly after we left the scene to head home, the newsroom directed us to a damaged home north of New Vienna, Ohio. Here’s the approximate location of the house relative to New Vienna:

Imagine what I felt arriving the scene and seeing this:

Whoa. What could cause this? I immediately went into investigation mode. Here’s a wide shot of this house and the yard around it:

Notice anything, even that this resolution? Most of the debris is to the left of the house. With this photo looking southeast, most of the debris is on the east or southeast side of the house, including all of this debris along the road:

Closer to the home, I found this wood board driven into the ground:

Whoa. That’s some force. The home owner (pictured above) is actually an electrical engineer at General Electric. He was thinking like I was; he wondered how there could be all of this debris so far away from the house, especially east of the house. The wind was coming from the northwest at the time; if damaging straight-line wind was the cause of this damage, why was there so much damage to the east of the house (including large, heavy parts of the walls)? In addition to the debris field, that board driven into the ground suggested to me this was a tornado.

After we shot our video at the house, we drove through New Vienna (north on State Route 73); there was a lot of tree damage there:

I did not see any structural damage, and all of the tree damage seemed to lean towards the south, east or southeast. The alignment of buildings and tree along the road reminded me of the Venturi Effect, possibly explaining how winds were accelerating through the town. More on the Venturi Effect is here: http://www.tech-faq.com/venturi-effect.html. In other words, winds – moving northwest to southeast through the town, or basically down S.R. 73 – were accelerating or at least traveling through the town like this:

This damage appears to be caused by straight-line winds. As I drove home, I had a visual of what the radar data might look like. While I had looked at radar briefly in real-time as the storm moved through Highland County, I had not looked at the radar data in detail.

Here is the radar loop from 3:04 to 3:49pm for this Highland County storm:

Here is the storm relative velocity (the Doppler part of Doppler radar or how the winds are moving relative to the radar [minus the motion of the storm to see rotation] in Wilmington, Ohio) loop of this storm from 3:04pm to 3:49pm:

From the radar’s lowest scan angle, red colors are winds moving away from the radar, green colors are winds moving towards the radar, and yellow colors are severe winds moving away from the radar. So the overall wind flow relative to the radar looked like this:

There’s no strong rotation here. Radar suggests mainly outflow winds. But there’s more! Let’s look specifically at the radar snapshot around 3:15pm:

There’s no hook echo or strong inflow notch. Let’s look at the base velocity data for the same area:

Winds were moving away from the radar near New Vienna at the time damage occurred. Normally, strong winds towards and strong winds away from the radar are close together near a tornado. So there’s no tornado right? Not so fast. The magnitude of the wind speeds near New Vienna matter:

See how wind speeds over New Vienna are stronger than where the blue arrow is? Imagine a pinwheel facing the sky just north of New Vienna. Which way would it rotate? Counter-clockwise…like most tornadoes do. If you’re having a tough time visualizing this, see what normalized rotation looked like:

The green area shows significant counter-clockwise rotation based on raar; in other words, this is where radar is detecting rotation and the possibility of a tornado.

The National Weather Service in Wilmington is responsible for determining if damage was from straight-line wind or a tornado. I don’t know if they will survey this Saturday. Based on the damage I saw, the Leesburg damage looks to be from straight-line wind, but the New Vienna damage is more complicated. After seeing it with my own two eyes, the damage north of New Vienna looks tornadic, but the damage in town is a close call.

We will see what the verdict is from the NWS!

When you think of Tri-State tornadoes, you may think of March 2, 2012 or April 9, 1999. If you’ve lived in the Cincinnati area for a while, you may also remember April 3, 1974. The tornadoes of June 2-3, 1990 are often forgotten because there were no fatalities from tornadoes that night. There were, however, roughly 40 injuries in southeastern Indiana and southwestern Ohio during the event; all of these injuries came from an F2 tornado extending from Ripley to Dearborn County and from an F4 tornado extending from Dearborn to Warren County:

The highest rated tornado in the Tri-State that night was an F4 that went through Harrison, Ohio and also caused damage up to Mason. This tornado began two miles west of Bright, Indiana and continued into northwestern Hamilton County, where 32 homes and five businesses were destroyed. Two 18-inch, 75-foot long, 5/8″ steel beams designed to withstand winds up to 250mph were twisted to the ground at a restaurant in Harrison. The tornado continued into southern and southeastern Butler County where 19 homes and 4 mobile homes were destroyed. 58 homes, 22 mobile homes, and five apartment buildings were damaged. The tornado ended about 1 mile southwest of Mason, Ohio in Warren County.

A little known fact about the Harrison area tornado is that the path of the tornado is not continuous despite official records listing the damage from Bright to Mason as one tornado. The tornado briefly lifted near New Baltimore, Ohio and settled back to the ground in Colerain Township near Pippin Road. While the tornado lifted, the path’s interruption was brief enough to count as one tornado per NWS directives. Current NWS directives (specifically, NWS Directive 10-1605) state that if a tornado’s path is interrupted for more than 2 miles OR more than 4 minutes, the tornadoes will be rated separately. This NCDC website suggests “a tornado that lifts off the ground for less that [sic] 5 minutes or 2.5 miles is considered a separate segment. If the tornado lifts off the ground for greater than 5 minutes or 2.5 miles, it is considered a separate tornado.” Official NWS records (from the National Climatic Data Center) suggest the tornado lifted near New Baltimore, Ohio at 10:10pm EST and touched down again in Colerain Township, Ohio at 10:14pm EST. While close to being two separate tornadoes, official records list the damage from Dearborn County to Warren County as one tornado. It is unclear to me which definition is correct and/or was the correct definition at the time. Here is a map showing the tornado’s path on the evening of June 2, 1990:

The F2 tornado that affected Ripley and Dearborn County that night produced 3 injures and caused mainly tree damage. The Hopewell Church in western Ripley County near Holton was, however, destroyed.

Radar images of this event are of poor quality, but it appears that a cyclic supercell was responsible for the damage extending from Holton to Mason. Other, weaker tornadoes were confirmed in Boone, Clermont, and Clinton County that night.

No one died in the Harrison area tornado of June 2, 1990. Including this one, there have only been three violent (F4, F5, EF4, or EF5) tornadoes in the Tri-State since 1950 that have not produced fatalities (the others being on April 3, 1974 and April 25, 1964).