Intense upper level low pressure brings arc of severe thunderstorms to portions of south central Nebraska during the afternoon hours of May 12th. A closed upper low pressure system over SW Nebraska lead to the development of a broken arc of mini-supercells, beginning around 1300-1400CDT. While most of south central Nebraska was in the dry slot of the storm system during the daytime hours, far north and northeastern portions of the CWA remained in the warm sector long enough to develop sufficient instability for strong to severe thunderstorms. The intense nature of the upper low, combined with significantly backed low level winds (and thus high storm relative helicity) lead to development of several low topped supercells that arched from the Nebraska Sandhills, ESE to near Ord and Columbus. A few hail and wind damage reports were received with this activity, but by far the most attention-grabbing portion of the event was a tornado in Greeley County. Damage was very limited with this tornado as it tracked over primarily pasture land in central Greeley County. However, this tornado had high notoriety, regionally and nationally, due to it's highly photogenic nature (well defined tornado in foreground and blue skies in the background), as well as proximity to several well known storm chasers. This was a relatively short-lived event, overall, with all of the severe activity occurring between 1300-1700CDT.

Hail in VALLEY, NEBRASKA
From 12-MAY-23 13:23:00 to 12-MAY-23 13:23:00 (CST-6)
Location: ELYRIA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POLK, NEBRASKA
From 12-MAY-23 14:17:00 to 12-MAY-23 14:17:00 (CST-6)
Location: OSCEOLA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in GREELEY, NEBRASKA
From 12-MAY-23 13:05:00 to 12-MAY-23 13:05:00 (CST-6)
Location: GREELEY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in NANCE, NEBRASKA
From 12-MAY-23 13:30:00 to 12-MAY-23 13:30:00 (CST-6)
Location: FULLERTON
Magnitude: 70.00 EG
Property damage: 500.00K
Crop damage: 0.00K
Reported by: NWS Employee

Wind gusts estimated to be near 70 MPH resulted in flipped irrigation pivots in eastern Nance County.

Tornado in GREELEY, NEBRASKA
From 12-MAY-23 13:25:00 to 12-MAY-23 13:42:00 (CST-6)
Location: SPALDING
Tornado F-scale: EF1
Property damage: 300.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed out of a northwestward tracking supercell that was located within a band of supercells that were rotating around a strong low pressure system over central Nebraska. The tornado formed right around 2:25 PM CDT and tracked over open pasture and recently planted fields mainly hitting several pivots and tree lines as it tracked northwest. No homes were impacted by this tornado. The worst damage appeared to be the flipped pivots, snapped cedar trees, and finally damage to at least 2 parked vehicles at the intersection of Highway 91 and Highway 281. The windows were blown out on two vehicles that were parked at this location and two large metal electrical transmission poles were leaning, but still standing at this intersection. After hitting the Highway 91 and 281 intersection the tornado continued onto the northwest over open road-less country across far north central Greeley county where based on video and surveying, it was believed to have lifted just shy of the Greeley/Wheeler County line. The maximum wind gust was estimated to be 105 MPH.