A complex of strong to severe thunderstorms raced southeastward through mainly the northeast half of South Central Nebraska on this Monday morning, causing a few marginally-severe wind gusts, but mainly just dumping more unwelcomed rain, promoting new flooding issues and/or exacerbating ongoing flooding. The heart of this storm complex tracked along a 20-30 mile wide swath centered from roughly Arcadia-Grand Island-Geneva, entering the Valley/Sherman counties area around 5 a.m. CDT and exiting the Fillmore County area into southeast Nebraska around 8 a.m. CDT. Along the way, the Grand Island airport ASOS measured an official 59 MPH gust and on unofficial mesonet near Polk reported 60 MPH. Ground-truth wind damage reports were quite limited, but several tree branches were downed in McCool Junction. Certainly though, the biggest impact from this event was heavy rainfall/flooding, as most places within the aforementioned swath tallied early morning amounts of 1.00-2.50, with a few higher totals including 3.00 near Cotesfield and 2.69 west of Doniphan. As a result, at least minor flooding of several creeks and rural roads occurred or continued within several local counties, including along the West Fork Big Blue River between Hastings and McCool Junction. Among a few of the more newsworthy flooding impacts, Grand Island not only saw widespread short-term street flooding, but the State Fairgrounds were swamped with several inches of standing water for a few hours, disrupting Day 4 of the Nebraska State Fair. Also in Hall County, ongoing flooding issues at the Amick Acres neighborhood west of Doniphan were worsened, with flooding subsequently persisting for several more days. To put the Hall County hydrologic situation into some numerical perspective, a CoCoRaHS observer near Doniphan measured an incredible 11.91 between Aug. 21-26 and 16.76 for the entire month! At Grand Island airport, the official Aug. 21-26 total was only 5.34, but the monthly total of 11.94 shattered the previous August record of 8.73 in 1977 (normal August rainfall at Grand Island is 3.12).
Breaking down the meteorological setup, it's worth noting that the primary storm cluster that traversed the local area between 5-8 a.m. CDT was not the only one of the morning, as it was preceded by a less-intense, non-severe batch of storms that roamed over many of the same areas 3-5 a.m. CDT. In the mid-upper levels, the pattern was seasonably-active, as South Central Nebraska resided under northwesterly flow, with shortwave disturbances tracking around the southern periphery of a large-scale trough centered over southern Canada. In the lower levels, convection was fed by warm air/moisture advection on the nose of a 30-35 knot low level jet. At the surface, a weak cold front gradually edged into the local area over the course of the morning. As the main storm complex pushed into South Central Nebraska, the mesoscale environment featured seasonably-strong deep-layer wind shear around 50 knots and 1000-2000 J/kg most-unstable CAPE.

Flood in HALL, NEBRASKA
From 26-AUG-19 06:30:00 to 26-AUG-19 09:30:00 (CST-6)
Location: GRAND IS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rainfall of 1 to 2 inches, much of which fell between 6 and 7 AM CDT, resulted in street flooding across a good portion of Grand Island, and also impacted the Nebraska State Fair. All of the public parking lots at the fairgrounds  were closed, and there were several inches of standing water through much of the area where concessions and carnival rides were located. This rain event brought the August total up to 11.46 at Central Nebraska Regional Airport (the previous August rain record for Grand Island had been 8.73 inches in 1977). In addition, August 2019 ended up as the second-wettest calendar month on record (for any month) in Grand Island, out of 125 years.

Hail in VALLEY, NEBRASKA
From 26-AUG-19 04:17:00 to 26-AUG-19 04:17:00 (CST-6)
Location: ARCADIA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Lightning in FILLMORE, NEBRASKA
From 26-AUG-19 06:30:00 to 26-AUG-19 06:30:00 (CST-6)
Location: GENEVA
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A lightning strike hit the Fillmore County courthouse and destroyed the flag pole on the top of the building, and also disabled the automatic door system.

Thunderstorm Wind in YORK, NEBRASKA
From 26-AUG-19 06:10:00 to 26-AUG-19 06:10:00 (CST-6)
Location: MC COOL JCT
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. Several tree branches, some at least 6 inches in diameter, were blown down.

Thunderstorm Wind in HALL, NEBRASKA
From 26-AUG-19 05:22:00 to 26-AUG-19 05:22:00 (CST-6)
Location: (GRI)GRAND IS RGNL A
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A 59 MPH wind gust was measured by the Central Nebraska Regional Airport ASOS.

Thunderstorm Wind in POLK, NEBRASKA
From 26-AUG-19 05:56:00 to 26-AUG-19 05:56:00 (CST-6)
Location: POLK
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A 60 MPH wind gust was measured by a mesonet station located 2 miles east of Polk.

Thunderstorm Wind in CLAY, NEBRASKA
From 26-AUG-19 06:00:00 to 26-AUG-19 06:00:00 (CST-6)
Location: HARVARD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 500.00K
Reported by: Public

Wind gusts were estimated to be near 60 MPH and were accompanied by dime size hail.