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. 

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Wisconsin Skies

A weekend "getaway" to Alma, Wisconsin along the Great River Road during the recent Labor Day weekend produced the following images. Above, the Dairyland Power Cooperative plant is shown looking southwest along the Mississippi River at 5:44 am CDT on Saturday September 2, 2023. Image is an 8 second exposure at f/7.1, ISO 100, 67mm focal length.

Altocumulus undulatus clouds spread the sky above a former church-turned-private residence in Alma on September 2.

Similar capture from the other side of the structure.

Moon above Lock and Dam #4 along the Mississippi River on Sunday morning, September 3. Nikon Z6ii camera.

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Special Super Blue Moon

What is a Blue Moon? A Blue Moon is defined as the second of two full moons occurring in a single month. What is a Super Moon? A Super Moon is defined as a full moon that makes its closest orbit to Earth (perigee). Put them together and you have a rare "Super Blue Moon," which makes the moon appear slightly larger than normal. This special event occurred in the skies of Eastern Iowa on Wednesday, August 30, 2023. The moon rose at 7:59 pm CDT, and reached maximum fullness by 8:36 pm. The composite image above looks southeast toward the rising moon from Lowe Park in Marion, Iowa at 8:15 pm. The sphere in the foreground is a stainless steel gazing ball located along a trail in the park. Above and slightly right of the moon is the 0.42 magnitude planet Saturn. Main image is a 1/6 second exposure at f/4.5, ISO 200, 70mm focal length. The moon image (below) was used for the composite above.

Moon capture at 8:17 pm. Image is a 1/200 second exposure at f/4.5, ISO 200, 70mm focal length. The next "Super Blue Moon" won't occur again until 2037. Nikon Z6ii camera.

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Cotton Wad Sky

A brief showing of Altocumulus Undulatus clouds in the skies of Cedar Rapids, Iowa on the morning of Saturday, August 19, 2023 produced these images. This view looks east. The clouds gave the appearance of cotton balls.

Another capture looking northwest. This type of cloud forms when there is moisture in the mid levels of altitude. Nikon D7200 DSLR camera.

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Two Rounds of Non-Severe Storms

A thin line of non-severe storms approached the Cedar Rapids, Iowa area during the afternoon of Monday, August 14, 2023. The panoramic image above stretches from north (left) to east (right), as seen from the back (west) grounds of Noelridge Christian Church at 3:29 pm CDT.

Radarscope image for 3:28 pm, with the line of storms shown to the northeast. This storm weakened and soon broke up.

Round Two, and this isolated event was a little stronger. The panorama above looks northwest from Bowman Woods Park in Cedar Rapids at 7:07 pm. Note the lowering feature at left.

Radarscope image for 7:06 pm. The most intense area of this cell is now due north of my location.

7:09 pm. Looking northeast at another lowering.

7:10 pm. Similar view. This storm produced some heavy rain and elevated wind before moving on. Nikon D7200 DSLR camera.

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Clouds Bring Down the Curtain on the Perseids Show Early

The early morning hours of Sunday, August 13 were considered the peak of the 2023 Perseids meteor shower, with 2:00 am until dawn being prime time viewing. I set up in Bowman Woods Park in Cedar Rapids, Iowa just after 2:00 am, hoping for a long and intense show. Lingering Canadian wildfire smoke probably didn't help matters, and the meteor shower started out slow. Then the disappointment really began to happen. Clouds from the west began approaching, and a lengthy stay appeared likely. The image above is a composite of five separate meteor streaks, with a 2:27 am capture being included in the base terrestrial image. Other captured streaks occurred at 2:09, 2:39, 2:31 and 2:59. Each image is a 13 second exposure at f/2.8, ISO 640, 11mm focal length. Also viewable in the image are the constellations Perseus (radiant source) at center, Auriga below Perseus,  and Taurus just above the tree line at lower right. The Pleiades star cluster is just above Taurus. The bright object at right is the -2.47 magnitude planet Jupiter.

While photographing the Perseids Meteor Shower at 2:51 am, a fast moving helicopter moved through my camera's field of view, and I captured its trail in this 13 second exposure. Note the presence of the encroaching clouds in the background.

3:13 am. Clouds are now veiling the stars and sky. In less than ten minutes this view of the sky (northeast) was entirely covered. I was forced to turn in early with a shortened and disappointing camera capture of the event. Nikon D7200 DSLR camera. 

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Energetic Windbag

Atmospheric conditions over the state of Iowa during the early afternoon hours of Friday. July 28, 2023 were juicy-- temperatures in the middle 90s F with dew points in the 70s. More ominously, Convective Available Potential Energy (CAPE) values were around 5000 joules per kilogram (J/Kg). CAPE is an indicator of instability and is the amount of fuel available to a developing thunderstorm. Extreme instability is considered above 4000J/Kg. Partly because of this, the Storm Prediction Center (SPC) posted an Enhanced Risk area from central Iowa to northwestern Indiana at 3:00 pm CDT (above). Also shown in the graphic are tornado, hail and wind outlooks.

Mesoscale Discussion 1754, posted around 4:00 pm, showing areas of interest for possible severe storms in eastern Nebraska and much of Iowa.

Now confirmed as Severe Thunderstorm Watch 560, valid from 5:00 pm.

Radarscope image of the severe thunderstorm watch polygon and forming storms at 5:02 pm.

Storm formation began in far eastern Nebraska and north central Iowa around 1:30 pm. The Nebraska cell went severe-warned around 4:45 pm. The Iowa cell went severe-warned around 5:25 pm, when it was located in northeast Wright County. This cell then went tornado-warned around 5:50 pm. Echo tops in some of these areas soared to a robust 66,000 feet! The three-panel College of DuPage (COD) satellite image above show storm initiation growth at 5:52 pm, 6:09 pm and 6:11 pm. 

Radarscope image for 5:58 pm, with severe and tornado warned areas shown west and north of Waterloo, Iowa.

The 6:11 pm image above shows two "eyes" in the cloud tops, probably overshooting tops.

Radarscope image for 6:26 pm. Note the hail core near Iowa Falls at left. It was around this time I headed out to select a spotting location ahead of the approaching storm. I changed my mind for locations north of Cedar Rapids three times! I finally decided to position myself more to the south and west to intercept the "tail end charlie" cell (that contained the hail core) that was tracking to the southeast.

Iowa Environmental Mesonet (IEM) mesoplot for 6:00 pm, showing conditions in my general area (yellow).

7:11 pm. Approaching US Highway 30 from the Interstate 380 on ramp in SW Cedar Rapids, Iowa. The underside of the severe-warned storm's anvil is in the background, the ADM plant in the foreground. 

Corresponding radar image, showing the storm cell from the above photograph at lower left, just west of Belle Plaine. 

7:29 pm. Now at my stationary spotting location-- at the parking lot of Schrader Tiling & Terrain LLC along the eastbound lanes of US Highway 30 in eastern Benton County, and about 3.25 miles southwest of Atkins, Iowa (41°57'45.69"N,  91°54'58.52"W). Storm clouds are beginning to gather in this view looking northwest.

7:37 pm. The juicy atmosphere was ample for mammatus cloud formations which were located under the thunderstorm's anvil, seen in this view looking southeast over the Schrader facility.

7:38 pm. Mammatus panorama with east direction at far left (and US Highway 30), and south at right.

7:38 pm radar screen capture. The former separated "tail end charlie" cell has now joined its neighbors and  is forming a squall line. 

7:40 pm. Similar mammatus capture.

7:46 pm. Looking north. Vigorous area of updraft.

7:51 pm. Radar image and my location (blue target icon).

7:52 pm. Shelf cloud from approaching storm now coming into view from the northwest. The storm was about 16 miles distant, near the town of Keystone, in Benton County. It was about this time that reports of potential 100 mph winds associated with this storm were circulated. My spotting vehicle is in the foreground. 

7:52 pm. Panoramic view of approaching shelf cloud.

7:55 pm. The gust front is now only about 9 miles distant, near the town of Newhall.

Corresponding radar image to photos above and below.

7:56 pm. Shelf cloud panorama. "Whale's Mouth" area forming at left. Storm is about 8 miles away.

7:57 pm. Similar image.

7:58 pm. Looking northeast. Northern flank of storm is about to overtake my position. US Highway 30 is in the background.

7:58 pm. "Whale's Mouth" toward left, as the leading edge overtakes my position from the northwest.

7:58 pm. Dirt and gravel from the parking lot is kicked up from the initial straight line wind gusts as the storm pushes through. I estimated these winds in the 60-65 mph range, exceeding the criteria for severe (58 mph +). Winds while I was here probably peaked at 70 mph, accompanied by torrential rain and dime size hail. Go Pro Hero 4 Silver video frame capture.

8:39 pm. The trailing edge of the storm coming into view to the northwest, with a peek of sunlight creating a brilliant sky. Shortly after this image was captured, I disengaged from this location and headed back toward home. Back toward home, wind speeds had approached 90 mph, knocking out power and downing trees. If I had stayed in the spotting location I left just before this one, I may have experienced that! Nikon D7200 DSLR camera.

9:46 pm. Radarscope capture showing my home location and the trailing end of the line of storms as it tracked through.

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