This late Monday evening the 25th into early Tuesday morning the 26th featured one of the most noteworthy, albeit very-localized heavy rain and flooding events of summer 2014 within South Central Nebraska, with the greatest concentration of 3+ inch amounts centered directly over and near the city of York. The vast majority of this rain fell during a three-hour period between 1130 pm-230 am CDT, with a few of the highest rain totals in the immediate York area featuring 6.40 on the southwest side of town (NeRAIN), 4.93 on the southeast side (NeRAIN) and 4.71 inches a few miles north of the city (NWS coop observer). As a result of this deluge, significant street flooding temporarily stranded several motorists during the night and Beaver Creek remained out of its banks well into the Tuesday daytime hours within the city. Although flooding in central York County was the main story on this night, hail up to quarter size was also reported in York, and farther west, penny to nickel size hail fell in Hastings and Phillips.
This event was triggered by the rapid 11 pm-12 am CDT initiation of a west-southwest to east-northeast corridor of elevated convection that started out no more than 10 to 25 miles wide, and extended from the Minden and Hastings areas in the west and then eastward through the Aurora and York areas. While this primary area of convection steadily ended from west-to-east during the next few hours as it expanded in area somewhat, the York area bore the brunt of heavy rainfall as it not only received heavy rain from the initial development, but also had to endure training convection moving in from the west. Although small pockets of weak thunderstorms lingered over South Central Nebraska throughout the night, the main heavy rain event wrapped up between 130-230 am CDT.
This was a fairly classic case of a narrow corridor of elevated nocturnal thunderstorms blossoming within the exit region of a modestly-strengthening low level jet centered near/slightly above 850 millibars. In the mid-upper levels, the local area resided with a zone of slightly enhanced southwesterly flow focused well-downstream from a positively tilted western United States trough centered over Nevada. At the surface, South Central Nebraska resided north of a generally west-east quasi-stationary front draped across Kansas. Around the time of late-evening convective initiation, mesoscale parameters featured around 1000 J/kg most-unstable CAPE and 0-6 kilometer deep layer wind shear around 30 knots.

Heavy Rain in YORK, NEBRASKA
From 25-AUG-14 22:00:00 to 26-AUG-14 02:30:00 (CST-6)
Location: YORK
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

The following reports are 24-hour rain totals, with the vast majority of rainfall occurring between 1130 pm and 2 am CDT. Around 1 mile southwest of downtown York, 6.40 inches of rain fell. This was from the NERAIN network. About 1 mile east southeast of York, 4.93 inches of rain was reported from the NERAIN network. About 3 miles north of York, 4.71 inches of rain occurred, reported from a cooperative observer. A total of 4.03 inches of rain fell at the York Airport. In Bradshaw, 3.20 inches of rain was recorded by a cooperative observer.

Flash Flood in YORK, NEBRASKA
From 25-AUG-14 23:00:00 to 26-AUG-14 03:00:00 (CST-6)
Location: BRADSHAW
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rainfall left some drivers stranded as flood waters spilled into the streets. York police reported that a number of motorists were stranded in their cars after trying to drive through high water. Rain flooded an area between Lincoln Ave. and Platte Ave. from 2nd to 6th streets. Beaver Creek, which runs through the center of York, was also well over its banks early Tuesday morning. Reports of submerged cars were also received via Facebook. A total of 6.4 inches of rain was measured about one mile southwest of York from an NERAIN report. Numerous other rain gages in the vicinity of York measured more than 4 inches of rain. The majority of rain fell between midnight and 2 am CDT.

Hail in ADAMS, NEBRASKA
From 25-AUG-14 22:26:00 to 25-AUG-14 22:26:00 (CST-6)
Location: HASTINGS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A few hail stones were as large as pennies, but most were smaller, in east central Hastings.

Hail in ADAMS, NEBRASKA
From 25-AUG-14 22:27:00 to 25-AUG-14 22:27:00 (CST-6)
Location: HASTINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail up to the size of nickels occurred along Showboat Road, just east of Hastings.

Hail in HAMILTON, NEBRASKA
From 25-AUG-14 22:53:00 to 25-AUG-14 22:53:00 (CST-6)
Location: PHILLIPS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This report was received via Facebook.

Hail in YORK, NEBRASKA
From 25-AUG-14 23:08:00 to 25-AUG-14 23:08:00 (CST-6)
Location: YORK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This report was received via Facebook.

Hail in YORK, NEBRASKA
From 25-AUG-14 23:22:00 to 25-AUG-14 23:22:00 (CST-6)
Location: YORK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A few hail stones up to the size of quarters occurred on the north side of York.