Hail up to the size of baseballs and severe winds occurred on this Wednesday evening. During the late afternoon hours, a small number of storms formed over north central Nebraska. While they were initially supercells, these storms weakened from destructive interference as they moved south-southeast. One storm did produce a little nickel size hail over southwest Valley county around 7 PM CST. The main show was an incredible supercell that developed near Mason City around that time. The storm moved across Sherman, Buffalo, and Kearney counties over the following 2 hours, and put on a spectacular lightning and cloud-structure show. The storm was all by itself. People were taking pictures of the storm as far away as Harlan County Lake. This storm produced hail up to the size of golf balls from near Litchfield all the way down to just east of Kearney. There were spotty areas of crop damage, from hail and wind, along the way. The largest hail was the size of baseballs in Hazard, but there must have been a small number as there was very little damage visible the following day. The storm probably remained severe into northern Kearney county, but no additional reports were received south of I-80. The storm then weakened after 9 PM CST. Another storm moved out of Custer county and into Valley county just after 8 PM CST. This storm moved along nearly the identical path of the first storm. The most intense portion of this storm was during its journey through eastern Buffalo county. Golf ball size hail was reported between Kearney and Gibbon at 950 PM CST. Because these storms affected the same area of Buffalo county, there is uncertainty on which storm produced the crop damage. These storms weakened and dissipated during the late evening hours. However, another intense multicell complex had formed over north central Nebraska. This complex moved across Nance, Polk, Merrick, and York counties between 1130 PM and 2 AM CST. A utility company reported some trees and tree limbs were blown down or snapped off in northern Polk county, resulting in some power outages between Silver Creek and Highway 81. The exact location(s) was unclear. A weather station near York also measured winds of 59 MPH.
These storms formed in the vicinity of a developing warm front, as cyclogonesis was occurring over South Dakota. Fairly flat west-northwest flow was over the U.S. with a subtropical high over New Mexico. A potent northwest-southeast-oriented shortwave  trough was progressing through the Dakota's. The nose of an anomalously strong jet streak was on the southern side of the trough. The evening and night were very muggy and warm. Temperatures fell from the 80s into the 70s, while dewpoints were in the lower 70s. Despite poor mid-level lapse rates, MUCAPE was 2500-3000 J/kg. Deep layer shear was around 50 kt, very strong for this time of the summer.

Hail in VALLEY, NEBRASKA
From 18-JUL-18 19:02:00 to 18-JUL-18 19:02:00 (CST-6)
Location: ARCADIA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in VALLEY, NEBRASKA
From 18-JUL-18 20:34:00 to 18-JUL-18 20:34:00 (CST-6)
Location: ARCADIA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm Wind in YORK, NEBRASKA
From 19-JUL-18 01:00:00 to 19-JUL-18 01:00:00 (CST-6)
Location: YORK
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in BUFFALO, NEBRASKA
From 18-JUL-18 20:13:00 to 18-JUL-18 20:26:00 (CST-6)
Location: PLEASANTON
Magnitude: 1.75 
Property damage: 500.00K
Crop damage: 10.00M
Reported by: Trained Spotter

Hail up to the size of golf balls was reported.

Hail in BUFFALO, NEBRASKA
From 18-JUL-18 20:43:00 to 18-JUL-18 20:43:00 (CST-6)
Location: GIBBON
Magnitude: 1.50 
Property damage: 25.00K
Crop damage: 1.00M
Reported by: Storm Chaser

Hail the size of quarters to half dollars was reported.

Hail in BUFFALO, NEBRASKA
From 18-JUL-18 21:50:00 to 18-JUL-18 21:50:00 (CST-6)
Location: GIBBON
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 1.00M
Reported by: Emergency Manager

Hail in SHERMAN, NEBRASKA
From 18-JUL-18 19:48:00 to 18-JUL-18 20:01:00 (CST-6)
Location: LITCHFIELD
Magnitude: 2.75 
Property damage: 250.00K
Crop damage: 1.00M
Reported by: Trained Spotter

Hail ranging in size from quarters to baseballs was reported along this path. The largest hail, tennis to baseball size, was reported in Hazard.