While the majority of South Central Nebraska enjoyed a seasonably-warm and tranquil Tuesday evening, it was a different story within a few far northeastern/east-central counties, where a pair of somewhat high-based supercells advanced south-southeastward, leaving behind swaths of mainly large hail but also more localized damaging winds. The first of these intense storms entered the local area into far eastern Nance County shortly after 7 p.m. CDT, striking Genoa and vicinity with a combination of estimated 70 MPH winds and nickel to quarter size hail. Around 8 p.m. CDT it reached central Polk County, pummeling the Osceola area with several minutes of hail up to 2 inches in diameter. An NeRAIN observer seven miles north of Osceola reported significantly stripped corn and that house flowers are now sticks. The supercell continued into eastern York County, still producing hail up to golf ball size in Thayer and ping pong balls east of McCool Junction. Around 9:30 p.m. CDT a weakening trend had commenced, but not before the storm brushed northeast Fillmore County on its way out of the local area and blew down a few tree branches near Exeter. Meanwhile, about 60 miles back to the northwest, another supercell somewhat-unexpectedly fired up over northern Nance County around 9 p.m. CDT. This storm was not as proficient of a large hail producer as its predecessor (largest reported was quarter size near Clarks and Hordville), but it packed more of a wind punch as its core started collapsing over the Hamilton-York County line between 10-10:30 p.m. CDT. Most notably, estimated 70 MPH gusts blew over a semi truck on Interstate 80 near the Hampton exit and also damaged a roof and broke power poles near Bradshaw. Shortly thereafter, this second supercell began dissipating, fading from radar over southeastern Fillmore County around 1130 p.m. CDT and bringing an end to all convection for the night.
Forecast-wise, this was considered an all-or-nothing setup for South Central Nebraska in the early morning local forecast discussion, as some computer models correctly predicted the presence of supercells locally, while others insisted that all regional convection would focus at least slightly east-northeast of the area altogether. This uncertainty was understandable given various pros and cons at play. One of the biggest pros for robust supercell development was seasonably-strong deep layer wind shear of 40-50 knots, as the area resided under pronounced northwesterly flow within the interface between an expansive ridge over the southwestern states and a deep southeast Canada trough. As for cons, they were mainly highlighted by seasonably-unimpressive low level moisture and resultant instability. Although afternoon temperatures soared to around 90 (F) to the south of a west-east oriented warm front across northeast Nebraska, dewpoints along the front struggled to reach the low-60s during peak heating, yielding fairly modest mixed-layer CAPE no higher than 1000-1500 J/kg. Ultimately though, persistent low-level convergence along the intersection of the  aforementioned warm front and a subtle, northeast-southwest oriented trough proved sufficient to spark convective initiation as early as 4 p.m. CDT about 60 miles to the north of South Central Nebraska. This early convection drifted more eastward initially, but eventually dove more southward as it intensified, allowing the first supercell to infiltrate far northeastern local counties. For a while it appeared this would be South Central Nebraska's only severe storm of the evening, but the second one likely ignited as the onset of a southwesterly low level jet converged into the first storm's trailing outflow.

Hail in NANCE, NEBRASKA
From 22-JUN-21 18:20:00 to 22-JUN-21 18:20:00 (CST-6)
Location: GENOA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Accompanying wind gusts were estimated to be near 60 MPH at times.

Hail in NANCE, NEBRASKA
From 22-JUN-21 20:04:00 to 22-JUN-21 20:04:00 (CST-6)
Location: BELGRADE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Thunderstorm Wind in NANCE, NEBRASKA
From 22-JUN-21 18:20:00 to 22-JUN-21 18:30:00 (CST-6)
Location: GENOA
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts were estimated to be around 70 MPH in Genoa, closer to 60 MPH three miles north of Genoa. Tree damage and nickel size hail was reported across Genoa.

Hail in POLK, NEBRASKA
From 22-JUN-21 19:08:00 to 22-JUN-21 19:20:00 (CST-6)
Location: OSCEOLA
Magnitude: 1.50 
Property damage: 50.00K
Crop damage: 5.00M
Reported by: Trained Spotter

Hail ranging from quarter size to ping pong ball size was reported along and near this path.

Hail in POLK, NEBRASKA
From 22-JUN-21 19:09:00 to 22-JUN-21 19:12:00 (CST-6)
Location: OSCEOLA
Magnitude: 2.00 
Property damage: 250.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail ranging from quarter size to two inches in diameter was reported across Osceola.

Hail in YORK, NEBRASKA
From 22-JUN-21 19:29:00 to 22-JUN-21 19:43:00 (CST-6)
Location: BENEDICT
Magnitude: 1.75 
Property damage: 50.00K
Crop damage: 5.00M
Reported by: Fire Department/Rescue

Hail ranging from quarter to golf ball size was reported along and near this path.

Hail in YORK, NEBRASKA
From 22-JUN-21 19:30:00 to 22-JUN-21 19:30:00 (CST-6)
Location: GRESHAM
Magnitude: 1.50 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: COOP Observer

Quarter to ping pong ball size hail was reported.

Thunderstorm Wind in FILLMORE, NEBRASKA
From 22-JUN-21 20:20:00 to 22-JUN-21 20:20:00 (CST-6)
Location: EXETER
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts estimated to be near 60 MPH resulted in some tree limbs of 2-4 inches in diameter blown down onto Highway 6.

Thunderstorm Wind in YORK, NEBRASKA
From 22-JUN-21 21:18:00 to 22-JUN-21 21:25:00 (CST-6)
Location: BRADSHAW
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Wind gusts were estimated to be 65 to 70 MPH. Roof damage and broken power poles were reported 2 miles east of Bradshaw.

Thunderstorm Wind in HAMILTON, NEBRASKA
From 22-JUN-21 21:25:00 to 22-JUN-21 21:25:00 (CST-6)
Location: HAMPTON
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts were estimated to be near 70 MPH by a storm chaser in the area. Emergency management reported that a semi-truck was blown over near mile marker 339 on Interstate 80, which is 1 mile east of the Hampton exit.

Hail in YORK, NEBRASKA
From 22-JUN-21 20:08:00 to 22-JUN-21 20:08:00 (CST-6)
Location: MC COOL JCT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in HAMILTON, NEBRASKA
From 22-JUN-21 20:50:00 to 22-JUN-21 21:00:00 (CST-6)
Location: HORDVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MERRICK, NEBRASKA
From 22-JUN-21 20:51:00 to 22-JUN-21 20:51:00 (CST-6)
Location: CLARKS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter