For mainly southeastern portions of South Central Nebraska (mainly southeast of a York-Red Cloud line), this was an active Friday evening and early Saturday morning of thunderstorms. Things started out with a smattering of large hail reports before transitioning to mainly a heavy rain and relatively minor flash flooding event, particularly within western Nuckolls and far eastern Webster counties where rain totals of 2-4 inches were common, and highlighted by 4.72 per an unofficial mesonet west-southwest of Nelson. As for hail, the largest reported stones up to golf ball size occurred in McCool Junction and southeast of Sutton. Severe-criteria wind reports were quite limited, but a mesonet southwest of Nelson gusted to 64 MPH and a completely separate batch of storms farther west yielded a 63 MPH mesonet gust near Cambridge. The most impactful flooding report involved a multiple-hour closure of Highway 136 in far western Nuckolls County due to water over the road. In addition, runoff from heavy rain promoted minor flooding along the Republican River in southern Nuckolls County, with the automated gauge near Hardy cresting at 11.66 ft. during the very early morning hours of Sunday the 16th (flood stage 11.0 ft.).
Breaking down event evolution, severe storms initially got underway between 8-10 p.m. CDT as a cluster of semi-discrete cells erupted within Clay, Fillmore and southern York counties, yielding the majority of the evening's hail reports. Then between 10 p.m. and midnight CDT and slightly to the southwest of the initial storms, additional severe convection and flooding rains blossomed over Nuckolls and eastern Webster counties. After midnight, the most intense storms gradually weakened and/or slipped south of the state line into Kansas, although weaker activity lingered a few more hours before ending altogether. Completely separate from (and several counties to the west of) the severe convection in southeastern counties, a small cluster of storms entered Furnas County from the west shortly before midnight CDT, generating the aforementioned severe gust near Cambridge before quickly weakening. Turning to the meteorological setup, a broad quasi-zonal flow regime was present in the mid-upper levels, featuring passing low-amplitude disturbances. At the surface, the initial evening development seemed to concentrate along a subtle, west-east front, in a mesoscale environment featuring a relatively potent combination of 2000-3000 J/kg mixed-layer CAPE and around 30 knots of deep-layer wind shear. In addition, convection was aided by warm air/moisture advection along the northwestern fringes of a nocturnal low level jet primarily aligned from southern Kansas into Missouri.

Thunderstorm Wind in FURNAS, NEBRASKA
From 14-JUN-19 22:44:00 to 14-JUN-19 22:44:00 (CST-6)
Location: CAMBRIDGE
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A 63 mph wind gust was measured by a mesonet station located 2 miles north-northeast of Cambridge.

Hail in CLAY, NEBRASKA
From 14-JUN-19 19:34:00 to 14-JUN-19 19:34:00 (CST-6)
Location: HARVARD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in YORK, NEBRASKA
From 14-JUN-19 19:57:00 to 14-JUN-19 20:00:00 (CST-6)
Location: MC COOL JCT
Magnitude: 1.75 
Property damage: 250.00K
Crop damage: 2.00M
Reported by: Fire Department/Rescue

Quarter to golf ball sized hail was reported.

Hail in CLAY, NEBRASKA
From 14-JUN-19 20:31:00 to 14-JUN-19 20:31:00 (CST-6)
Location: SUTTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Hail in FILLMORE, NEBRASKA
From 14-JUN-19 20:37:00 to 14-JUN-19 20:37:00 (CST-6)
Location: GRAFTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CLAY, NEBRASKA
From 14-JUN-19 20:48:00 to 14-JUN-19 20:48:00 (CST-6)
Location: SUTTON
Magnitude: 1.50 
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FILLMORE, NEBRASKA
From 14-JUN-19 20:55:00 to 14-JUN-19 21:00:00 (CST-6)
Location: GRAFTON
Magnitude: 1.75 
Property damage: 250.00K
Crop damage: 2.00M
Reported by: Trained Spotter

Quarter to golf ball size hail was accompanied by 50 to 60 MPH wind gusts.

Thunderstorm Wind in FILLMORE, NEBRASKA
From 14-JUN-19 21:00:00 to 14-JUN-19 21:00:00 (CST-6)
Location: GRAFTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated wind gusts of 50 to 60 MPH accompanied quarter to golf ball size hail.

Hail in WEBSTER, NEBRASKA
From 14-JUN-19 21:02:00 to 14-JUN-19 21:02:00 (CST-6)
Location: COWLES
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FILLMORE, NEBRASKA
From 14-JUN-19 21:28:00 to 14-JUN-19 21:28:00 (CST-6)
Location: SHICKLEY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in NUCKOLLS, NEBRASKA
From 14-JUN-19 22:00:00 to 14-JUN-19 22:00:00 (CST-6)
Location: LAWRENCE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in NUCKOLLS, NEBRASKA
From 14-JUN-19 22:09:00 to 14-JUN-19 22:09:00 (CST-6)
Location: NELSON
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A 64 mph wind gust was measured by a mesonet station located 6 miles southwest of Nelson.

Hail in NUCKOLLS, NEBRASKA
From 14-JUN-19 23:10:00 to 14-JUN-19 23:10:00 (CST-6)
Location: SUPERIOR
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in NUCKOLLS, NEBRASKA
From 14-JUN-19 22:30:00 to 15-JUN-19 03:30:00 (CST-6)
Location: LAWRENCE
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding occurred four miles west of Nelson where a culvert had washed out, and also US Highway 136 was under water five miles east-northeast of Guide Rock.

Heavy Rain in NUCKOLLS, NEBRASKA
From 14-JUN-19 06:00:00 to 15-JUN-19 06:00:00 (CST-6)
Location: BOSTWICK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

These are rain totals over the past 24-hours, but most rain fell between 10 pm CDT on the 14th and 4 AM CDT on the 15th. This includes unofficial emergency manager reports of 3.5 to 4.0 inches in and around Bostwick, with 4.00 inches measured 1 mile north of Bostwick. A 24-hour rainfall of 4.72 inches fell 7 miles west-southwest of Nelson, and 3.44 inches was measured 7 miles south-southeast of Lawrence, reported in CoCoRaHS. Also, the Nuckolls County emergency manager reported that Highway 136 was under water about 5 miles east-northeast of Guide Rock.