A large area of 3 to 5 inches of rain occurred south of Highway 6 on this Monday afternoon and night, along with a couple isolated reports of severe weather. Scattered multicell thunderstorms began forming early, just after noon CST, north of McCook. As these storms moved northeast, they were rapidly joined by numerous other storms. By 5 PM CST, scattered thunderstorms covered south central Nebraska, south of Interstate 80 between Highways 283 and 281. Over time, the most potent cells were the newest ones forming on the southwest edge of the expanding rain shield. By 6 PM CST, cell mergers there resulted in a short northeast-southwest oriented line segment of storms along the Furnas-Harlan County border. This line moved southeast into northern Kansas. As this occurred, and through the evening, more scattered storms continued to form to the west and southwest of the departing rain shield. By 1200 AM CST, the southwest edge of the precipitation area began moving northeast across the rest of south central Nebraska, with the strongest storms eventually becoming focused only on the southwest edge once again. By 4 AM CST, a multicellular line had formed from just east of Kearney to Hastings to Nelson, with a large shield of stratiform rain downstream. This line collapsed from northwest to southeast, weakened, and exited south central Nebraska around 7 AM CST Tuesday. Repeated cell development resulted in heavy rainfall amounts with 2 inch amounts common along Interstate 80 from Lexington to Grand Island. The heaviest amounts were south of Highway 6, especially along and just north of Highway 136, across Furnas, Harlan, Franklin, Webster, and Nuckolls Counties, where 3 to 5 inches fell. The highest amount was 5.55 inches in the town of Wilcox. Flood warnings were issued and minor flooding did occur along parts of the Republican River near Guide Rock. Flooding also occurred along Thompson Creek, with the gauge at Riverton briefly rising to moderate flood stage. It is likely that parts of Riverton did experience some flooding, but no impacts were received. A couple storms produced isolated severe weather, with 58 mph winds measured near Red Cloud, and hail the size of nickels in Wilcox.
These storms all formed in the warm sector of a deep low pressure system which was over central Canada. Its slow-moving cool front was over the Dakota's and the northern Rockies, while its warm front was east of the region, over Minnesota and Iowa. In the upper-levels, a subtropical high was over Oklahoma and encompassed the middle of the Country. The westerlies extended from the Pacific Northwest to Hudson Bay, with a weak trough over the eastern U.S. As the initial thunderstorms developed, temperatures were in the lower 90s, with dewpoints in the 60s. Mid-level lapse rates were low, resulting in MLCAPE generally between 1000 and 1900 J/kg. Effective deep layer shear was around 20 kts. The persistent thunderstorm development, particularly in the evening and overnight hours was associated with a 45 kt low-level jet. Nighttime MUCAPE levels were between 500 and 1000 J/kg.

Heavy Rain in FRANKLIN, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: HILDRETH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.90 inches was measured.

Heavy Rain in WEBSTER, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: BLADEN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.82 inches was measured.

Heavy Rain in HARLAN, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: RAGAN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.61 inches was measured.

Heavy Rain in HALL, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: CAIRO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.55 inches was measured.

Heavy Rain in FRANKLIN, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: HILDRETH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.40 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: NORA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.30 inches was measured.

Heavy Rain in ADAMS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: PAULINE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.10 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: NELSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.16 inches was measured.

Heavy Rain in WEBSTER, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: GUIDE ROCK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.22 inches was measured.

Heavy Rain in PHELPS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: HOLDREGE ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

A storm total rainfall amount of 3.28 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: NORA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.34 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: LAWRENCE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.35 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: ANGUS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.41 inches was measured.

Heavy Rain in DAWSON, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: LEXINGTON ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

A storm total rainfall amount of 3.45 inches was measured.

Heavy Rain in FRANKLIN, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: CAMPBELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A storm total rainfall amount of 3.46 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: NELSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.83 inches was measured.

Heavy Rain in KEARNEY, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: MINDEN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 3.91 inches was measured.

Heavy Rain in NUCKOLLS, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: RUSKIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.00 inches was measured.

Hail in KEARNEY, NEBRASKA
From 17-JUL-17 15:41:00 to 17-JUL-17 15:41:00 (CST-6)
Location: WILCOX
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WEBSTER, NEBRASKA
From 17-JUL-17 19:37:00 to 17-JUL-17 19:39:00 (CST-6)
Location: COWLES
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Heavy Rain in KEARNEY, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: WILCOX
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 5.55 inches was measured.

Heavy Rain in FRANKLIN, NEBRASKA
From 17-JUL-17 06:00:00 to 18-JUL-17 06:00:00 (CST-6)
Location: HILDRETH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A storm total rainfall amount of 4.94 inches was measured.