The 24-hour period between the early mornings of Saturday the 7th and Sunday the 8th featured several rounds of thunderstorms within South Central Nebraska. However, by far the most prominent round focused between 6-10 p.m. CDT, during which time a burst of fairly widespread strong to severe activity affected mainly the southeast half of the area...especially east of a line from Franklin-St. Paul-Fullerton. Although ground-truth reports were somewhat limited considering that 16 Severe Thunderstorm Warnings were issued during these four hours, there were a handful of hail reports up to golf ball size along with a few mesonet-measured severe wind gusts (including 68 MPH near Lawrence and 63 MPH near Polk). A few of the more notable hail reports included: golf ball size near Giltner and Lawrence; ping pong ball size near Fairfield. Within the Tri Cities, parts of both Grand Island and Hastings observed small hail up to dime-nickel size, but for Grand Island the bigger story was actually heavy rain and a few rounds of fairly minor urban flooding as multiple storms cumulatively dumped a widespread 2-3 inches of rain within a bullseye centered directly over the city. However, the overall heaviest rain within South Central Nebraska actually concentrated within a southwest-northeast swath through the heart of Polk County, where amounts of 2.50-3.50 were common (including 3.35 in Osceola). Meanwhile, the vast majority of the 24-county area observed much lower and highly-variable rain amounts ranging from only a few hundredths up to around 1.50.
Breaking down event evolution/timing and meteorological background, weak/non-severe convection percolated over much of South Central Nebraska throughout much of  the morning and afternoon, downstream from a seasonably-potent mid level shortwave trough slowly approaching from the NE/WY/CO border area. However, this activity diminished enough by late afternoon to allow considerable instability to build, aided by surface temperatures climbing into the mid-80s to around 90 (F) in the presence of healthy dewpoints mainly upper 60s-low 70s. By 6 p.m. CDT, the resultant mesoscale environment featured a fairly potent combination of 3000-4000 J/kg mixed-layer CAPE and 30-35 knots of deep-layer wind shear. Despite a lack of prominent surface boundaries within the area (only a fairly weak trough axis), the first initially-isolated strong-to-severe local storms of the day flared up between 6-7:30 p.m. CDT, one over Polk County (which dumped quarter size hail in Osceola) and another that lifted north out of Kansas into Webster/Nuckolls counties. Then, the ensuing few hours saw quite an uptick in the coverage of strong to severe storms within several central/eastern local counties. By around 10 p.m. CDT this activity quickly weakened below severe limits and started gradually departing off to the east. However, with a modest low level jet acting upon lingering elevated instability, additional flare-ups of spotty strong to perhaps marginally-severe storms (unverified) occurred mainly 1-4 a.m. CDT on the 8th, with a few of the most intense cells over Webster and Hall counties. Once this late-night round weakened/dissipated, most all of South Central Nebraska was finally convection-free by 5:30 a.m. CDT.

Hail in POLK, NEBRASKA
From 07-AUG-21 17:39:00 to 07-AUG-21 17:40:00 (CST-6)
Location: OSCEOLA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in NUCKOLLS, NEBRASKA
From 07-AUG-21 18:35:00 to 07-AUG-21 18:35:00 (CST-6)
Location: LAWRENCE
Magnitude: 1.75 
Property damage: 50.00K
Crop damage: 500.00K
Reported by: Public

Thunderstorm Wind in NUCKOLLS, NEBRASKA
From 07-AUG-21 18:36:00 to 07-AUG-21 18:36:00 (CST-6)
Location: LAWRENCE
Magnitude: 68.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A wind gust of 68 MPH was measured by a mesonet station located two miles east of Lawrence.

Hail in CLAY, NEBRASKA
From 07-AUG-21 18:55:00 to 07-AUG-21 18:56:00 (CST-6)
Location: FAIRFIELD
Magnitude: 1.50 
Property damage: 50.00K
Crop damage: 500.00K
Reported by: Trained Spotter

Hail ranging in size from quarters to ping pong balls was reported.

Hail in ADAMS, NEBRASKA
From 07-AUG-21 19:09:00 to 07-AUG-21 19:09:00 (CST-6)
Location: HASTINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, NEBRASKA
From 07-AUG-21 19:20:00 to 07-AUG-21 19:20:00 (CST-6)
Location: HASTINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in HAMILTON, NEBRASKA
From 07-AUG-21 19:20:00 to 07-AUG-21 19:22:00 (CST-6)
Location: GILTNER
Magnitude: 1.75 
Property damage: 100.00K
Crop damage: 3.00M
Reported by: Emergency Manager

Hail ranging in size from quarters to golf balls was reported.

Hail in HAMILTON, NEBRASKA
From 07-AUG-21 19:33:00 to 07-AUG-21 19:33:00 (CST-6)
Location: AURORA
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in HALL, NEBRASKA
From 07-AUG-21 19:42:00 to 07-AUG-21 19:42:00 (CST-6)
Location: GRAND IS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in POLK, NEBRASKA
From 07-AUG-21 20:18:00 to 07-AUG-21 20:18:00 (CST-6)
Location: POLK
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A wind gust of 63 MPH was measured by a mesonet station located two miles east of Polk.

Hail in HALL, NEBRASKA
From 08-AUG-21 01:53:00 to 08-AUG-21 01:53:00 (CST-6)
Location: GRAND IS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center