Epic Storm Chase, Great Bonding

 

Discussions of high instability, warm fronts, triple points and atmospheric forcing in the region of eastern Nebraska, northeastern Kansas, northwestern Missouri and western Iowa several days in advance of Friday, April 26, 2024 all indicated the potential for a significant severe weather event. The Storm Prediction Center (SPC) posted an Enhanced Risk for these areas two days in advance. Above are National Oceanic and Atmospheric (NOAA) forecast graphics for the Tornado Outlook (left) and Hail Outlook, valid from 12:30 pm CDT on April 25.

My son Ryan had five days off from work starting Thursday, April 25 and we discussed the possibility of a  storm chase for April 26, with an additional two days (April 27-28) of storm chasing on the table. Conditions continued to look favorable for severe weather (including strong tornadoes) early in the morning of April 26. We left Cedar Rapids, Iowa just after 9:00 am with the towns of Shenandoah or Atlantic, Iowa as our target areas. As we approached these areas however, a severe-warned cell was already firing up near the town of Belleville, Nebraska (Radarscope image above) at 12:47 pm, and tracking to the northeast toward Lincoln. With no time to lose, the decision was made to continue forward across the Missouri River and into the state of Nebraska. 

About the same time, Mesoscale Discussion 526 was posted, with a 95% probability of the issuance of tornado watch for the designated area (shown) being forecasted.

12:55 pm. Tornado Watch 140 is issued for much of the eastern half of Nebraska, and extreme western Iowa, valid until 7:00 pm CDT.

Forming severe-warned supercells are evident in this radar image at 1:10 pm.

1:26 pm. Close-up radar image in the Fairbury, Nebraska area with areas of hail evident within the severe-warned polygon.

1:33 pm. Supercell storms are intensifying, with the center storm now tornado warned. All storms are tracking to the northeast.

1:40 pm. Tornado-warned cell is tracking toward Lincoln, Nebraska and our current chase location (target icon).

1:42 pm. Second supercell near the town of Friend, Nebraska goes tornado warned. 

1:47 pm. Close-up radar image of same area.

1:53 pm. Radarscope close-up dual-pane image, with reflectivity image at top and velocity image at bottom. Reflectivity image shows a forming tornado "hook echo" signature. The bottom image shows the bright area of a tornado couplet.  

Similar more expansive view of the image above it. The red dots are storm chasers.

Ryan Alliss' electronic chasing equipment (top-to-bottom): iPhone 15 Pro for streaming, GPS, Radarscope.

2:05 pm. Storm chasing now begins in earnest. Image looks north at swirling clouds from I-80 ALT, located about 2.5 miles southeast of Seward, Nebraska, indicating a volatile atmosphere. 

2:09 pm. We are now located north of Seward, and having to make the choice of intercepting the more northern tornado warned supercell (left) or the more southern one at lower right. Our position is the blue target icon. 

2:25 pm. Image looks northeast along Road 322, about 2.5 miles west of Seward, Nebraska in Seward County. Ryan points his cell phone toward the sky while streaming, with mammatus clouds in the background.

2:32 pm. First Emergency Alert sounds on my cell phone!

2:37 pm. Looking northwest at a vigorous cauliflower updraft as seen from the northern outskirts of Seward, Nebraska in Seward County.

2:43 pm. Looking northwest from the side of Highway 280, just south of Highway 808, about 5 miles north of Seward, Nebraska. Ryan observes developing tornado-warned storm.

2:45 pm. Same location. Looking north at rotating storm. Clear slot at left. Updraft and inflow cloud at right. Note the line of storm chasers in the background at right.

2:55 pm. We are momentarily pulled off to the side of Highway 15, about .7-mile south of the junction with Highway 66 in Butler County, Nebraska. This vigorously rotating storm would produce our first tornado in mere minutes.

2:55 pm. Back on the road again. A Dwight (Nebraska) Rural Fire Truck parks in the middle of the road about .6-mile south of Highway 66--not to block traffic, but to warn of the danger ahead. 

2:56 pm. Looking north from Highway 15 at Highway 66. This brief, weak tornado dropped just as we were approaching the intersection. Note the striking circular rotation around the funnel, and the storm chasers stopped in the foreground. 

2:56 pm. Closer-in image.

2:58 pm. We have turned right (east) onto Highway 66 and pulled off to the side of the road a short distance from Highway 15. A funnel drops to the ground in this view looking north. Like the first tornado, this was a brief and weak event. 

2:59 pm. The tornado lifts after having been on the ground for just a few seconds.

2:59 pm. Ryan streams the storm.

3:00 pm. Similar view looking northeast.

3:10 pm. Looking southeast at anvil topped supercells, as seen from Highway 66 about 4 miles east of Dwight, Nebraska in Butler County. These tornado-warned storms would eventually move into Iowa and impact the town of Minden. 

3:11 pm. Similar view.

3:18 pm. Eastbound on County Road A in Saunders County, Nebraska, about 2.8 miles southeast of Valparaiso, Nebraska. Although not distinct in this image, ground circulation indicated a tornado contact.

3:18 pm. Second Emergency Alert.

3:32 pm. We observed hailstones on the side of the road while traveling on County Road A in Saunders County, Nebraska, about 4.6 miles east of Ceresco. Many were very large in size! The fallen hail was confined to a small area--maybe a half-mile. We did not see any hail falling. This is the first hailstone I collected--shaped sort of like a hockey puck.

3:34 pm. A conglomerate style hailstone.

 

3:37 pm. Using my trusty measuring caliper on a hailstone and discovering it measured an astounding 3.8 inches in width--the largest hailstone I've ever seen!

3:46 pm. Looking south at storm while eastbound on Ashland Road, about 1.75 miles west of the town of Ashland, Nebraska in Saunders County.

4:10 pm. Radar image with a very distinct tornado hook echo signature, located near Washington, Nebraska, just northwest of Omaha.

4:28 pm. Our location is just north of Omaha (target icon), tornado-warned polygon areas, and we're heading toward Iowa.

4:35 pm. Incredibly active radar image of the Omaha area.

4:48 pm. No surprise here--another Emergency Alert.

5:07 pm. University of Illinois Doppler On Wheels (DOW) truck seen while we were northbound on Laredo Avenue (L23), about 3.3 miles southeast of Pisgah, Iowa. The DOW team was led by Dr. Josh Wurman. 

5:23 pm. Looking north from Lincoln Way Street near US Highway 30 (background left) in Woodbine, Iowa in Harrison County. Leading a line of storm chasers is the University of Illinois Doppler On Wheels (DOW) truck. 

5:25 pm. Northbound on Loess Hills Trail about 3 miles north of the town of Missouri Valley, Iowa in Harrison County. Wedge tornado can be seen on the horizon.

5:33 pm. Yet another Emergency Alert, this one adding "A dangerous storm is approaching current location. Tornado threat: high."

5:39 pm. Ominous Radarscope image for 5:39 pm, with hail over the town of Minden, and the distinct hook echo of a tornado about to arrive from the south. We did not fully know about the disaster that had befallen Minden until the next day, but unfortunately had a good idea it would happen from this image. Our location target icon is just northeast of the town of Tennant.

5:44 pm. Traveling south (southwest) on County Road M16, about 1.4 miles northeast of Tennant, Iowa. Wedge tornado at center background.

5:47 pm. Looking southwest at a multi-vortex tornado as seen from County Road M16, about .7-mile south of the town of Tennant, Iowa in Shelby County. The tornado had just devastated the town of Minden.

5:51 pm. Looking southwest at two tornadoes on the ground--broader tornado (background), and satellite tornado in the foreground. We are stopped on Street F58, with County Road M16 in the background. Storm is approaching our location.

5:51 pm. Single tornado in an ever-changing vortex whirl.

5:52 pm. Satellite tornado back on the ground, accompanying the main tornado.

5:52 pm. Yours truly posing in front of the oncoming tornado. (Ryan Alliss photo)

 

5:52 pm. Close-up of two tornadoes on the ground.

5:52 pm. The car at right came up to us and exclaimed, "Are you alright? Do you need help?" After we assured them we were fine, they sped off toward the left. The tornado would track over this very spot a short time after we had departed from it. 

5:53 pm. The tornado moves relentlessly forward, and appears to have momentarily lifted. It was now time to go! We followed the direction of the vehicle in the background. 

5:54 pm. Racing briefly toward the tornado's track, but then a quick turn away east (left). The storm appears as a low hanging wall cloud at this moment, but would recycle into a wedge tornado in just minutes. Ryan shouted to me, "you'd better get your pictures of it now, because we're getting out of here!"

5:56 pm. Stationary again. Looking west at approaching wedge tornado as seen from Street F58, about 5 miles southwest of the town of Harlan, Iowa in Shelby County.

5:58 pm. Wedge tornado draws nearer and was moving toward the lower right in this image. I had the impression of an evil living, breathing entity as it relentlessly churned on. 

5:58 pm. Simliar image.

5:58 pm. Similar image. 

5:58 pm. Ryan streams the wedge tornado from beside our vehicle. The tornado passed 1.25-mile to our northwest. Inflow winds here were around 30-40 mph.

6:06 pm. Looking northwest at wedge tornado while northbound on US Highway 59 on the south edge of Harlan, Iowa in Shelby County.

6:08 pm. Vigorously rotating wedge tornado looking northwest from our stationary position on Highway 44 on the west edge of Harlan. 

6:20 pm. Looking at rotating updraft structure, still containing the wedge tornado, while northbound on County Road M47 in Shelby County, Iowa. Nikon Z6ii camera.

9:17 pm. iPhone 11 video frame capture. Eastbound on Interstate 80 near Newton, Iowa, driving inside a tornado-warned storm. Around this time after an epic and tiring storm chase, we decided to forego the chasing of the next two day's severe weather setup, and returned home to Cedar Rapids just before midnight.

During this storm chase I debuted my experimentation of the Nikon app "Snapbridge," which connects to my Nikon mirrorless camera via Bluetooth, and geo-stamps the latitude/longitude coordinates of each capture. This experiment was successful and proved invaluable in recording our locations.

11:08 pm. DOW data analysis of Harlan tornado. There were 19 confirmed reports of tornadoes in Nebraska and Iowa on this day. (The state of Iowa experienced a record 41 tornadoes in the month of April).

Our storm chasing map for Friday, April 26, 2024, includes tornado tracks in our general vicinity. The epic 15-hour, 865-mile chase saw 5-6 tornadoes, and was highlighted by the visually amazing high-end EF3 Harlan tornado. But on a more serious note, our thoughts and prayers go out to those whose lives and property were impacted by the Omaha and Minden events.