Memorable Memorial Day

On the Memorial Day holiday (Monday, May 27, 2024) the Storm Prediction Center (SPC) had only a Marginal Risk (Level 1) outlook posted for eastern Iowa, and I wasn't too expectant of any severe weather until my weather radio alert suddenly sounded in the afternoon. Sliding north and east of Cedar Rapids was a small isolated severe-warned storm cell. I thought, okay I'll get in the car and hopefully capture a few shots with my camera from down the street. I did so, with no other spotting gear other than the camera. The Radarscope image above from 3:44 pm CDT shows that storm cell.

But almost immediately, I could see there was a lot more to it than a cool shot from a distance, and after driving past some obstructing trees to the north, an obvious wall cloud hung beneath the storm, and the chase was on. The image above shows that wall cloud while northbound on Alburnett Road in the northern part of Marion, Iowa at 3:42 pm.

3:46 pm. Now eastbound on County Home Road north of Marion, with the wall cloud to my northeast.

3:51 pm. Eastbound on Austin Road, just east of Highway 13 northeast of Marion. Storm is now showing a more menacing tornadic appearance. Downdraft is at left.

3:53 pm. Radarscope reflectivity (top) and velocity (bottom) return of the storm.

3:55 pm. Radar capture. Note the hail core (lavender color) just northeast of my location (target icon).

3:56 pm. Slowly following the storm on gravel roads, here looking northeast from Barrett Road, south of Austin Road, one mile east of Highway 13. The lowering at center (right of the downdraft) was noticeably rotating and I phoned in a report of this to the National Weather Service in the Quad Cities.

3:59 pm. The lowering has now tightened and continues to rotate. I expected a brief funnel or tornado from this, but it did not occur. Another storm report to the NWS.

4:22 pm radar capture. I had driven as far east as Whittier, Iowa, then decided to abandon this storm for another promising line of storms approaching the Cedar Rapids metro area from the northwest. 

4:28 pm. Brief stationary spotting location on White Road, about a half-mile west of North Marion Road, north of Marion, Iowa. This image looks northwest at the new line of approaching severe-warned storms. The most intense area is at the far right.

4:38 pm. Relocated again at my final stationary location-- looking north from North Marion Road, about .75-mile north of White Road. This ominous looking severe warned storm is tracking slightly to my north and east.

4:38 radar image. Of particular interest is the small hook-like appendage just north of me which was soon to show itself visually.

4:41 pm. A funnel-like feature dips low to the ground, confirming the radar signature.

4:41 pm. Looking north at approaching storm from my spotting location. 

4:42 pm. Similar image.

4:43 pm. Radar capture. Appendage contains a small area of hail.

4:44 pm. Storm is evolving into a more linear shelf cloud...but it would produce a surprise soon!

4:45 pm. Similar zoomed-in capture. The whitish area on the leading edge of this line of storms at right center is beginning to rotate. 

4:46 pm. Dual-pane radar image, with the bright area at bottom (velocity) in the same location as the new rotation.

4:47 pm. A better view of the rotating feature (center), resembling a down-reaching hand. 

4:47 pm. Similar view.

4:48 pm. Looking northeast. Now with a more obvious funnel. This was probably a Quasi-Linear Convective System (QLCS) "transient" tornado along the leading edge of the squall line. Reported this to the NWS.

4:51 pm. QLCS line is being replaced by heavy rain behind it. This storm would for the most part pass to my north and east. What started as a seemingly innocent isolated storm cell would turn into a memorable day on Memorial Day! 

Postscript: The last image from my raw photo catalogue for this event seems to provide a tantalizing visual that indeed there was a brief QLCS tornado touchdown (center, between two trees) at 4:54 pm. Nikon Z6ii camera. 

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Blazes of Glory

Family members who live in rural Shueyville, Iowa hold a bonfire about twice a year for friends and family (a sort of Fourth of July viewing event). The following images were captured during the bonfire on Saturday evening, May 11, 2024. This was the day following a significant Northern Lights event across the globe, and I had hoped to capture predicted reoccurrences this night along with the bonfire itself. Alas, that did not happen. Images look north. Image above is a 1/60 second exposure at f/4, ISO 3600, 24mm focal length.

1.3 second exposure at f/4, ISO 800, 24mm focal length.

2.5 second exposure at f/4, ISO 800, 24mm focal length.

4 second exposure at f/4, ISO 200, 24mm focal length.

4 second exposure at f/4, ISO 200, 24mm focal length.

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Powerful Storm System Moves East, Loses Momentum

As active severe weather season continues, a setup for another severe event on May 21, 2024 similar to that of April 26 was forecast a couple of days in advance by the Storm Prediction Center (SPC). An updated outlook released at 12:54 am on Tuesday, April 26 enlarged the Moderate Risk (Level 4) area that had been in place over eastern Iowa the day before (above). 

Also issued is this large area of 15% hatched tornado risk.

Severe Thunderstorm Watch 275 is issued at 6:15 am for the majority of central and southern Iowa, and valid until 1:00 pm.

1:10 pm. Tornado Watch 277 is issued for much of Iowa, a small portion of northwest Illinois and southeast Minnesota.

3:00 pm. Updated convective outlook from the SPC as seen from Pivotal Weather's website, showing categorical, tornado, hail and wind outlooks.

3:20 pm. In short order comes Mesoscale Discussion 875, outlining an area of southwest Iowa that is favorable for strong tornadoes.

3:21 pm. Radarscope map of Iowa where an intense line of storms with multiple tornado and severe warned polygons are seen all up and down its length. The white circled area shows the location of Greenfield, Iowa, which would soon be ravaged by an EF4 tornado. Storms were tracking ENE.

4:17 pm. Radarscope showing the storm system as it continued east. It has now arrived over the Des Moines metropolitan area. Behind and west of the storm is a large polygon denoting flash flooding. Now inexplicably, the southern portion of the system began to lose energy despite a very favorable environment, perplexing some storm chasers located there.

About 4:40 pm I make the decision to drive northwest on Interstate 380 from Cedar Rapids to a position where I can intercept a leading severe-warned cell south of Waterloo. My reasoning was that if this situation did not pan out, I could always turn back south and make a play on other cells that were still farther west. I arrived at my first spotting location, the northbound I-380 weigh station, north of Brandon and south of La Porte City, Iowa. Above is a look at my spotting gear (5:33 pm) which includes cell phone (radar), amateur radio, CB/weather radio, Davis Vantage Vue weather data console, and my Nikon Z6ii camera.

5:42 pm. This is a look west at the incoming severe-warned storm cell from my I-380 weigh station spotting location. Very soon I would make the decision to leave this spot and head back south, as a I saw a discrete tornado-warned cell headed for the Cedar Rapids area. (I probably should have stayed here because as it turned out this was the more active cell).

Radar image for 5:42 pm. The approaching severe-warned storm can be seen at upper left. The target icon is my location.

6:31 pm. Now having arrived at my new spotting location at the BP Mart on County Home Road near the Toddville, Iowa exit of I-380. An inflow cloud can be seen along the northwestern horizon, feeding into the approaching storm (toward left).

6:37 pm. Radar image showing my former storm (upper left) now being tornado warned, and my new approaching storm having its tornado warning dropped... (of course!).

6:38 pm. Panorama of approaching severe-warned storm. Storm is about 27 miles distant. 

6:43 pm. Storm showing an interesting and vigorous updraft feature (just above horizon). A Robins, Iowa fire department vehicle is parked in the foreground.

6:48 pm. Radarscope dual pane mode, showing reflectivity (top) and velocity at bottom. The area shown with a white arrow was where a tornado might have resided.  

6:53 pm. A photogenic inflow cloud looking northwest.

6:55 pm. Storm, now about 10 miles distant, looking more ominous.

6:57 pm. Looking WNW. Possible forming funnel.

6:58 pm. Looking less like a funnel. The storm was now becoming more outflow dominant, with the winds blowing toward me.

7:01 pm. Storm forming a bit of a shelf cloud and is now about 5 miles distant.

7:02 pm. Spotters and truckers watch the incoming storm, which is minutes away. The two truck drivers at right decided to park their rig and wait out the storm before resuming north to Waterloo. 

7:02 pm. Inflow cloud panorama feeding into the storm (left).

7:04 pm. Severe-warned storm cell is almost upon my location and is showing a bit of a hook echo feature between the towns of Marengo and Fairfax. 

7:26 pm. Heading back home on County Home Road after most of the storm had passed. This image looks northeast at the departing storm and its strong rain shaft. The storm system in eastern Iowa weakened considerably compared to when it was in western Iowa. Heavy rain fell here, some elevated winds and pea size hail. Minor damage occurred. Nikon Z6ii camera.

The town of Greenfield, Iowa caught the brunt of the severe weather event, with four fatalities and much of the town destroyed. The tornado was recently upgraded from an EF3 to an EF4. It reached a maximum of 1,000 yards wide and traveled 44 miles. Thoughts and prayers go out to all those who were affected by this deadly tornado. This is why reports from ground-truth storm spotters is so important!

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