Between the mid-afternoon of Tuesday the 25th and early morning of Wednesday the 26th, mainly the eastern half of South Central Nebraska endured two rounds of severe thunderstorms and heavy rainfall, with the first round by far the most impactful as it produced some of the largest hail of 2019 within the area (up to 3 diameter). Examining Round 1 in more detail, it unfolded from 4-8 p.m. CDT within several counties south of Interstate 80 and east of Highway 183, but with the majority of action focused within Adams, Webster and Nuckolls counties. The primary player here was an initially isolated, high-precipitation supercell that developed over western Adams County, gradually growing upscale into more of a supercell cluster as it surged southeastward before departing into northern Kansas. This storm was a prolific hail-producer, particularly within southwestern Adams County where there were numerous reports of stones ranging from quarter to larger than baseball size. The area in and near Holstein was particularly hard-hit, as hail as large as 3 was documented there by an NWS employee (although the vast majority of stones were smaller than this). As this massive storm sank farther south it became increasingly outflow-dominant and more of a wind-producer, with several gusts of 55-70 MPH reported in the Guide Rock and Superior areas. Independent of this storm of the day, other severe storms flared up during the afternoon and early evening within counties such as Clay/Fillmore/Franklin, producing hail of 2 diameter near Ong and golf ball size in Naponee. Rainfall-wise, though not extreme, amounts of 1.50-2.50 fell within much of Adams/Webster counties. This led to minor flooding on the Little Blue River, with the gauge near Deweese cresting at 10.3 feet on the afternoon of the 26th (flood stage 10 ft.).
After Round 1 departed into Kansas, all was quiet on the local front for several hours. However, Round 2 got underway after 1 a.m. CDT on the 26th and persisted until past sunrise. This round of convection was not as intense, mainly producing heavy rainfall, sub-severe wind gusts and small hail within northeastern portions of the area (mainly northeast of an Ord-York line). However, there were a few severe-criteria reports including quarter size hail in York and a 61 MPH wind gust near Waco. Technically, Round 2 consisted of a few separate areas of storms: one small cluster that blew up over York County along the nose of a nocturnal low level jet and another larger complex that expanded across several northeastern counties between 3-7 a.m. CDT before finally weakening and departing the vast majority of South Central Nebraska by 9 a.m. CDT. Rainfall totals of 1.50-3.00 were fairly common with this early-AM activity, highlighted by NeRAIN totals of 3.60 near York and 3.33 north of Osceola. Resultant flooding was relatively minor, including along the Clear Creek in northern Polk County, which crested at 8.3 feet on the morning of the 27th (flood stage 8 ft.).
For yielding so many severe weather reports, this was actually a fairly weakly-forced event in the mid-upper levels, with Nebraska positioned along the southern periphery of broad westerly flow and no significant shortwave troughs of note. However, the intense afternoon-early evening convection was clearly tied to low-level convergence along a west-east oriented, quasi-stationary surface front. As afternoon temperatures climbed into the upper 80s F, the mesoscale environment became quite supportive of severe storms (including supercells), featuring 2000-3000 J/kg mixed-layer CAPE and 30-40 knots of deep-layer wind shear. Later in the night, Round 2 was fueled by a classic increase in convergence/moisture transport within the exit region of a 30-40 knot southwesterly low-level jet.

Hail in ADAMS, NEBRASKA
From 25-JUN-19 15:04:00 to 25-JUN-19 15:04:00 (CST-6)
Location: HOLSTEIN
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CLAY, NEBRASKA
From 25-JUN-19 15:17:00 to 25-JUN-19 15:17:00 (CST-6)
Location: ONG
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FILLMORE, NEBRASKA
From 25-JUN-19 15:28:00 to 25-JUN-19 15:28:00 (CST-6)
Location: SHICKLEY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Hail in ADAMS, NEBRASKA
From 25-JUN-19 15:30:00 to 25-JUN-19 15:39:00 (CST-6)
Location: HOLSTEIN
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail ranging in size from ping pong to tennis ball size was reported along this path.

Hail in ADAMS, NEBRASKA
From 25-JUN-19 15:56:00 to 25-JUN-19 15:56:00 (CST-6)
Location: ROSELAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ADAMS, NEBRASKA
From 25-JUN-19 16:05:00 to 25-JUN-19 16:15:00 (CST-6)
Location: HOLSTEIN
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail ranging in size from golf balls to 3 inches in diameter was reported. About a half hour after the hail had stopped, an NWS employee reported that the diameter of hail left on the ground was up to 3 inches.

Hail in ADAMS, NEBRASKA
From 25-JUN-19 16:10:00 to 25-JUN-19 16:10:00 (CST-6)
Location: PAULINE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in CLAY, NEBRASKA
From 25-JUN-19 16:14:00 to 25-JUN-19 16:14:00 (CST-6)
Location: ONG
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, NEBRASKA
From 25-JUN-19 16:21:00 to 25-JUN-19 16:21:00 (CST-6)
Location: HOLSTEIN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Hail in FILLMORE, NEBRASKA
From 25-JUN-19 16:31:00 to 25-JUN-19 16:35:00 (CST-6)
Location: SHICKLEY
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail ranging in size from quarters up to 2 inches in diameter was reported.

Hail in FILLMORE, NEBRASKA
From 25-JUN-19 16:32:00 to 25-JUN-19 16:32:00 (CST-6)
Location: SHICKLEY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, NEBRASKA
From 25-JUN-19 16:34:00 to 25-JUN-19 16:34:00 (CST-6)
Location: HOLSTEIN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in WEBSTER, NEBRASKA
From 25-JUN-19 16:39:00 to 25-JUN-19 16:39:00 (CST-6)
Location: BLUE HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in ADAMS, NEBRASKA
From 25-JUN-19 16:55:00 to 25-JUN-19 16:55:00 (CST-6)
Location: HOLSTEIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WEBSTER, NEBRASKA
From 25-JUN-19 17:05:00 to 25-JUN-19 17:05:00 (CST-6)
Location: COWLES
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to be near 60 MPH.

Thunderstorm Wind in WEBSTER, NEBRASKA
From 25-JUN-19 17:13:00 to 25-JUN-19 17:13:00 (CST-6)
Location: GUIDE ROCK
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in WEBSTER, NEBRASKA
From 25-JUN-19 17:20:00 to 25-JUN-19 17:23:00 (CST-6)
Location: BLADEN
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to half dollar size hail was reported.

Hail in CLAY, NEBRASKA
From 25-JUN-19 17:31:00 to 25-JUN-19 17:31:00 (CST-6)
Location: INLAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WEBSTER, NEBRASKA
From 25-JUN-19 18:06:00 to 25-JUN-19 18:06:00 (CST-6)
Location: RED CLOUD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in NUCKOLLS, NEBRASKA
From 25-JUN-19 17:28:00 to 25-JUN-19 17:28:00 (CST-6)
Location: NELSON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to be near 70 MPH.

Hail in NUCKOLLS, NEBRASKA
From 25-JUN-19 18:11:00 to 25-JUN-19 18:13:00 (CST-6)
Location: SUPERIOR
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter to golf ball size hail was reported.

Hail in FRANKLIN, NEBRASKA
From 25-JUN-19 18:14:00 to 25-JUN-19 18:14:00 (CST-6)
Location: NAPONEE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in FRANKLIN, NEBRASKA
From 25-JUN-19 18:32:00 to 25-JUN-19 18:32:00 (CST-6)
Location: RIVERTON
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in NUCKOLLS, NEBRASKA
From 25-JUN-19 17:47:00 to 25-JUN-19 17:47:00 (CST-6)
Location: SUPERIOR
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to be near 60 MPH.

Hail in YORK, NEBRASKA
From 26-JUN-19 00:35:00 to 26-JUN-19 00:35:00 (CST-6)
Location: YORK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in YORK, NEBRASKA
From 26-JUN-19 01:25:00 to 26-JUN-19 01:25:00 (CST-6)
Location: YORK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in YORK, NEBRASKA
From 26-JUN-19 04:06:00 to 26-JUN-19 04:06:00 (CST-6)
Location: WACO
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A 61 MPH wind gust was measured by a mesonet station located approximately one-half mile east of Waco.

Heavy Rain in YORK, NEBRASKA
From 25-JUN-19 05:45:00 to 26-JUN-19 05:45:00 (CST-6)
Location: YORK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A CoCoRaHS station recorded a rain total of 3.60 inches for the day, with rain ongoing at observation time. Most rain fell early morning of the 26th.

Heavy Rain in POLK, NEBRASKA
From 25-JUN-19 06:00:00 to 26-JUN-19 06:00:00 (CST-6)
Location: OSCEOLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An NERAIN observer recorded a 24-hour rainfall of 3.33 inches 7 miles north of Osceola. Another NERAIN observer recorded a 24-hour rainfall of 3.25 inches 4 miles west northwest of Shelby. Most rain fell early morning of the 26th.

Flood in WEBSTER, NEBRASKA
From 26-JUN-19 01:00:00 to 26-JUN-19 14:00:00 (CST-6)
Location: GUIDE ROCK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Overflow water from Pawnee Lake damaged a short section of railroad track. There was still a small amount of standing water at 3 pm.