A Tornado When You'd Least Expect It

Chances for severe weather in Eastern Iowa during the afternoon/evening hours of Friday, September 22, 2023 were not great (as the Storm Prediction Center graphic above issued at 2:53 pm shows), with a better chance expected the following day. To my surprise, I received a lightning notification for my area just after 5:00 pm CDT. A line of storms that had begun to form in Jasper County in Central Iowa just before 3:00 pm was now located in eastern Benton County, tracking northeast. I was not expecting much from this development, so I took with me only my camera and tripod to capture some possible cloud formations. I opted for Lowe Park in Marion, Iowa for my observation location as the storm progressed. 

Just before 5:00 pm the National Weather Service issued a tornado warning after a spotter reported a "tornado on the ground" near Blairstown in Benton County. (The tornado would later be rated EFU). Radarscope capture. The blue target icon at right is my location.

I arrived at Lowe Park just before 5:30 pm, but after monitoring radar soon opted for a better location to intercept the storm, and that was the area of County Home Road and Interstate 380. Radarscope capture for 5:39 pm. 

Westbound on County Home Road I could see in the distance scores of headlights leaving the Tuma Soccer Complex, and quickly realized parents were leaving en masse with their children to escape the approach of a possible tornado. Radarscope image for 5:43 pm.

Emergency alert occurring at 6:00 pm. Shortly thereafter I arrived at my new spotting location--The BP Mart at County Home Road and Interstate 380 near Toddville, Iowa. 

Dual-pane Radarscope image for 6:15 pm, with reflectivity scan on top and velocity at bottom.

6:21 pm. Looking southwest at the approaching storm from the BP Mart. The storm was tracking to the northeast, which would bring it just west of this location. I was here only with my camera and tripod, as my usual spotting equipment (ham & weather radio, weather station, Go Pro camera, etc.) were still back home. 

6:30 pm. Storm is showing a tornadic structure and an inflow tail cloud (right).

6:36 pm. Similar panoramic view from the BP Mart near Toddville.

6:41 pm. Zoomed in image of the approaching tornado-warned storm. Structure is showing striations and a rotating base. Image looks southwest.

6:47 pm. Looking west at a low rotating base, with a feeder inflow cloud at right.

6:50 pm. Radarscope dual-pane view, with a velocity "hot spot" just east of Palo, Iowa.

6:51 pm. Corresponding photo to the radar image above it. Storm is displaying a collar cloud, with an ominous dark rotating cloud base beneath it. 

6:53 pm. Panorama image of the tornado-warned storm. The storm was located near Palo, only about 5 miles distant.

6:55 pm. Downdraft rain and hail core at center. The storm is beginning to occlude with the arrival of this feature. Strong inflow winds behind me were beginning to shift to my front as the storm transitioned to outflow at this location. 

6:58 pm. Similar panorama image.

7:06 pm. Looking WNW. "Doughnut" RFD gap containing rising scud, as the most intense area of the storm began to pass my location (toward the right).

7:15 pm. Possible funnel cloud looking northwest. As the storm began to pass to my west and north, and with growing darkness setting in, I decided to wrap up spotting operations here and head back east toward home. 

Eastbound back on County Home Road, I noticed (with each lightning flash) a still-very robust and persisting mesocyclone and wall cloud to my northwest. At Alburnett Road I quickly decided to turn left (north), then temporarily stop for some night photos at the Pioneer Marion Research Center. Lightning flashes revealed a low wall cloud, at times appearing to touch the ground. Wall cloud was about 14 miles distant, near the town of Walker in northern Linn County. This image was captured at 7:37 pm and is a 10 second exposure at f/4, ISO 200, 24mm focal length.

7:37 pm. Similar image.

7:39 pm. 15 second exposure at f/4, ISO 125 and 24mm focal length. 

The following day (Saturday, September 23) had a higher risk for severe weather than Friday, but would be a "bust" for the Cedar Rapids metro area. A decided contrast in forecasts and eventual outcomes! Nikon Z6ii camera.