A mesoscale convective system produced pockets of high winds and wind damage just after midnight on this Saturday morning. During the evening hours of Friday, scattered small clusters of multi-cell thunderstorms occurred over southwest Nebraska and northwest Kansas. The clusters over southwest Nebraska were moving to the east and the clusters over northwest Kansas were moving northeast. Between 10 and 11 PM CST, as these two areas of thunderstorms, and their outflows, began to merge, thunderstorm coverage began to increase as new thunderstorms formed between McCook and Lexington. The increase in coverage resulted in storm mergers and the formation of a larger multicell mesoscale convective system. Between 11 PM and 12 AM CST, the orientation of the MCS temporarily became northeast to southwest as new cells continued to develop along the Platte River. The MCS then morphed more into a circular shape as it moved northeast along Highway 30 from Grand Island to Columbus. Initially, some low-end severe hail occurred in parts of Furnas and Phelps counties, but as the MCS matured, severe winds became dominant. Powerful downburst winds occurred in portions of Kearney, Adams, Hall, Hamilton, and Merrick counties. The highest measured wind gust was 69 mph at a home weather station near the town of Norman. Other measured gusts included 58 mph at the Grand Island airport and 60 mph at the Hastings airport. Widespread wind gusts between 50 and 57 mph occurred surrounding these areas and even far away from where the thunderstorms actually occurred. Winds were measured at 50 mph as far south as Red Cloud. Large tree limbs were snapped off in some spots around Grand Island and in Central City. Near the Platte River, just south of Central City, large tree limbs fell on a house and landed on top of vehicles.
These storms formed along and ahead of a Canadian cold front. The flow aloft was west-southwest from California to Maine and low in amplitude. There was no strong forcing aloft affecting the Central Plains. Before the thunderstorms moved in, temperatures were in the middle 70s with dewpoints in the lower 70s. Mid-level lapse rates were very steep, near 8.5 C/km. This resulted in very high instability with MUCAPE of 3000-4000 J/kg. Deep layer shear was around 30 kt.
This thunderstorm event was the first of several episodes of heavy rain which led to a very wet start of September for portions of south central Nebraska. Later in the evening on this Saturday, waves of thunderstorms formed over north central Kansas and repeatedly moved northeast into south central Nebraska with the greatest persistence south and east of Hastings. These waves of heavy rain continued through the night. There was a break from heavy rain during the day Sunday, but the next episode of heavy rain moved in Sunday evening. By daybreak on Monday, September 3rd, rainfall amounts totaled 3 to 5 inches across portions of northern Franklin, southern Adams, and southern Clay counties, as well as most of Fillmore, Webster, Nuckolls, and Thayer counties. This resulted in localized flash flooding with low spots in some county roads being washed out and Highway 4 being closed between Carleton and Davenport. As water drained into the headwaters of the Little Blue River, the river rapidly rose with minor flooding occurring. At Deweese, the river gauge peaked at 10.86 ft during the day Monday. Flood Stage is 10.0 ft.

Hail in PHELPS, NEBRASKA
From 01-SEP-18 00:00:00 to 01-SEP-18 00:00:00 (CST-6)
Location: HOLDREGE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm Wind in HALL, NEBRASKA
From 01-SEP-18 02:17:00 to 01-SEP-18 02:17:00 (CST-6)
Location: DONIPHAN
Magnitude: 56.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Employee

A gust of 64 MPH was measured by the employee's anemometer.

Thunderstorm Wind in KEARNEY, NEBRASKA
From 01-SEP-18 00:33:00 to 01-SEP-18 00:33:00 (CST-6)
Location: NORMAN
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in ADAMS, NEBRASKA
From 01-SEP-18 00:34:00 to 01-SEP-18 00:34:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in HALL, NEBRASKA
From 01-SEP-18 01:03:00 to 01-SEP-18 01:03:00 (CST-6)
Location: (GRI)GRAND IS RGNL A
Magnitude: 50.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: ASOS

Some tree damage was reported on the northeastern side of Grand Island. One large limb, approximately 1 foot in diameter, was downed.

Thunderstorm Wind in HAMILTON, NEBRASKA
From 01-SEP-18 01:23:00 to 01-SEP-18 01:23:00 (CST-6)
Location: MARQUETTE
Magnitude: 60.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Social Media

Tree limbs were downed in the area.

Thunderstorm Wind in MERRICK, NEBRASKA
From 01-SEP-18 01:26:00 to 01-SEP-18 01:26:00 (CST-6)
Location: CENTRAL CITY
Magnitude: 60.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Public

Tree limbs were downed in the area.

Heavy Rain in ADAMS, NEBRASKA
From 01-SEP-18 06:00:00 to 02-SEP-18 06:00:00 (CST-6)
Location: HOLSTEIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24 hour rainfall total of 5 inches was reported, with the brunt of the rain falling between 5 PM CDT on the 1st and 4 AM CDT on the 2nd. Other area totals included 4.20 inches near Roseland and 3.62 inches and 3.20 inches in the Pauline area.

Heavy Rain in KEARNEY, NEBRASKA
From 01-SEP-18 06:00:00 to 02-SEP-18 06:00:00 (CST-6)
Location: NORMAN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24 hour rainfall total of 4.80 inches was reported, with the brunt of the rain falling between 5 PM CDT on the 1st and 4 AM CDT on the 2nd.

Heavy Rain in FRANKLIN, NEBRASKA
From 01-SEP-18 06:00:00 to 02-SEP-18 06:00:00 (CST-6)
Location: HILDRETH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Twenty-four hour rainfall totals of 4.40 and 3.79 inches was reported in the Hildreth area, with the brunt of the rain falling between 5 PM CDT on the 1st and 4 AM CDT on the 2nd.

Heavy Rain in CLAY, NEBRASKA
From 01-SEP-18 06:00:00 to 02-SEP-18 06:00:00 (CST-6)
Location: FAIRFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24 hour rainfall total of 4 inches was reported, with the brunt of the rain falling between 5 PM CDT on the 1st and 4 AM CDT on the 2nd. A total of 3.5 inches was also reported in the Lawrence area.

Heavy Rain in WEBSTER, NEBRASKA
From 01-SEP-18 06:00:00 to 02-SEP-18 06:00:00 (CST-6)
Location: BLUE HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24 hour rainfall total of 3.71 inches was reported, with the brunt of the rain falling between 5 PM CDT on the 1st and 4 AM CDT on the 2nd.

Flash Flood in THAYER, NEBRASKA
From 02-SEP-18 21:00:00 to 03-SEP-18 02:00:00 (CST-6)
Location: BRUNING
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

In addition to the rain that had fallen across the area on the 1st, radar estimation and measured amounts showed an additional 3 to 5 inches of rain falling across portions of the warned area the night of the 2nd. Much of this rain fell over a short period of time, resulting in water running over some area roads, including portions of Highway 4 between Carleton and Davenport.

Flash Flood in NUCKOLLS, NEBRASKA
From 02-SEP-18 21:00:00 to 03-SEP-18 02:00:00 (CST-6)
Location: OAK
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

In addition to the rain that had fallen across the area on the 1st, radar estimation and measured amounts showed an additional 3 to 5 inches of rain falling across portions of the warned area the night of the 2nd. Much of this rain fell over a short period of time, resulting in water running over some area roads, including portions of Highway 4 between Carleton and Davenport.

Flash Flood in CLAY, NEBRASKA
From 02-SEP-18 21:00:00 to 03-SEP-18 02:00:00 (CST-6)
Location: ONG
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

In addition to the rain that had fallen across the area on the 1st, radar estimation and measured amounts showed an additional 3 to 5 inches of rain falling across portions of the warned area the night of the 2nd. Much of this rain fell over a short period of time, resulting in water running over some area roads, including portions of Highway 4 between Carleton and Davenport.

Flash Flood in FILLMORE, NEBRASKA
From 02-SEP-18 21:00:00 to 03-SEP-18 02:00:00 (CST-6)
Location: SHICKLEY
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

In addition to the rain that had fallen across the area on the 1st, radar estimation and measured amounts showed an additional 3 to 5 inches of rain falling across portions of the warned area the night of the 2nd. Much of this rain fell over a short period of time, resulting in water running over some area roads, including portions of Highway 4 between Carleton and Davenport.

Flood in ADAMS, NEBRASKA
From 02-SEP-18 03:00:00 to 03-SEP-18 03:00:00 (CST-6)
Location: PAULINE
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain across the area, ranging anywhere from 3 to 6 inches, resulted in a few rural roads being washed out in the Holstein area. Flooding was also reported in the Crystal Lake State Recreation Area, and while the park was not closed, campers were encouraged to leave.