In terms of widespread, high-impact severe weather, the 24-hour period commencing on Sunday evening the 19th was likely the worst of the 2011 severe weather season for much of South Central Nebraska. The initial rounds of significant severe storms targeted the area during a 7-hour stretch centered from 9 PM CDT Sunday evening to 4 AM CDT Monday morning. During this nocturnal event, multiple severe supercell and multicell storms pounded mainly the northwest half of South Central Nebraska, or locations northwest of a line from Beaver City to Grand Island to Osceola. Generally speaking, severe weather during this 7-hour period came in three separate rounds, although there was some overlap in both time and area. Despite a favorable environment for tornadic development, no tornadoes were confirmed during this event.
The first round of severe weather, centered between 9 PM and 11 PM CDT, involved one large, intense supercell storm that drifted east out of southwest Nebraska, primarily impacting Furnas, Gosper, Harlan and Phelps Counties. This storm resulted in several reports of destructive hail up to tennis ball size, and winds of at least 60-70 MPH. One of the hardest hit areas was northern Furnas County in and around Cambridge and Arapahoe, where damage reports included the displacement of a 5-ton air handling unit atop the hospital in Cambridge, and a stock trailer thrown into a corn field.
As the initial supercell started to gradually weaken, a new area of vigorous severe storm development took place north of Interstate 80, expanding in coverage between 11 PM and 2 AM CDT. The most intense storm during this time frame tracked nearly due east from Sherman County to northern Polk County, with reports along the way including hail to the size of tennis balls and baseballs. Some of the worst known wind damage occurred in Merrick County, where estimated winds to 80 MPH destroyed an old grain elevator between Clarks and Silver Creek.
As activity ramped up north of Interstate 80, the third episode of severe weather got underway back to the southwest around 1230 AM CDT, as a new cluster of storms entered the Dawson to Furnas County corridor from the west, impacting many of the same areas as the initial supercell a few hours prior. Yet again, the Cambridge area saw strong winds and hail to around baseball size. In a gradually weakening state, this complex of storms eventually rode northeast through the Kearney, Grand Island and Central City areas, before all storms finally exited South Central Nebraska around 430 AM CDT.
This long-lasting onslaught of severe weather resulted from a very favorable synoptic severe weather setup for this time of year, with South Central Nebraska positioned slightly north of a well-defined surface warm front lifting northward from Kansas into southeast Nebraska. Aloft, a powerful, highly amplified mid-level trough was centered over the Central Rockies, spreading increasing wind fields and upper level divergence downstream over the Central Plains. In addition, a very strong southerly low-level jet stream took direct aim on South Central Nebraska during the evening and overnight hours, with speeds at the 850-millibar level increasing to 60-70 knots near the Nebraska-Kansas border. Just to name a few, some of the favorable severe weather parameters late in the evening included at least 2000-3000 J/kg most-unstable CAPE, 50-60 knots of deep-layer vertical wind shear, and 30-40 knots of surface to 1-kilometer low-level vertical shear. Despite the widespread coverage of storms, locally heavy rainfall totals were held down in the 1-3 inch range, with no significant flooding impacts.

Thunderstorm Wind in FURNAS, NEBRASKA
From 19-JUN-11 21:05:00 to 19-JUN-11 21:05:00 (CST-6)
Location: EDISON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts were estimated at 65 MPH.

Hail in GOSPER, NEBRASKA
From 19-JUN-11 23:58:00 to 19-JUN-11 23:58:00 (CST-6)
Location: ELWOOD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in HALL, NEBRASKA
From 20-JUN-11 00:20:00 to 20-JUN-11 00:20:00 (CST-6)
Location: ALDA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in BUFFALO, NEBRASKA
From 20-JUN-11 01:11:00 to 20-JUN-11 01:11:00 (CST-6)
Location: KEARNEY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MERRICK, NEBRASKA
From 20-JUN-11 02:27:00 to 20-JUN-11 02:27:00 (CST-6)
Location: CHAPMAN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts were estimated at 65 MPH.

Thunderstorm Wind in MERRICK, NEBRASKA
From 20-JUN-11 02:30:00 to 20-JUN-11 02:30:00 (CST-6)
Location: CENTRAL CITY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts were estimated at 60 MPH.

Heavy Rain in GOSPER, NEBRASKA
From 19-JUN-11 06:00:00 to 20-JUN-11 06:00:00 (CST-6)
Location: ELWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total rainfall of 3 inches was reported by a NeRAIN observer.

Thunderstorm Wind in HOWARD, NEBRASKA
From 19-JUN-11 22:40:00 to 19-JUN-11 22:40:00 (CST-6)
Location: ELBA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Wind gusts were estimated at 60 MPH.

Thunderstorm Wind in FURNAS, NEBRASKA
From 19-JUN-11 23:46:00 to 19-JUN-11 23:46:00 (CST-6)
Location: CAMBRIDGE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Wind gusts were estimated between 60 and 70 MPH.

Thunderstorm Wind in FURNAS, NEBRASKA
From 19-JUN-11 20:00:00 to 19-JUN-11 20:10:00 (CST-6)
Location: CAMBRIDGE
Magnitude: 61.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts were estimated between 60 and 70 MPH.  Damage reports included main transmission lines being blown down, uprooted trees and roof damage, an overturned stock trailer and grain cart, and air conditioning unit and window damage at the local hospital.

Thunderstorm Wind in FURNAS, NEBRASKA
From 19-JUN-11 20:38:00 to 19-JUN-11 20:38:00 (CST-6)
Location: ARAPAHOE
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts were estimated at 65 MPH.

Hail in FURNAS, NEBRASKA
From 19-JUN-11 20:59:00 to 19-JUN-11 20:59:00 (CST-6)
Location: ARAPAHOE
Magnitude: 2.50 
Property damage: 50.00K
Crop damage: 500.00K
Reported by: Storm Chaser

Hail in GOSPER, NEBRASKA
From 19-JUN-11 21:03:00 to 19-JUN-11 21:03:00 (CST-6)
Location: ELWOOD
Magnitude: 1.75 
Property damage: 50.00K
Crop damage: 250.00K
Reported by: Law Enforcement

Hail in FURNAS, NEBRASKA
From 19-JUN-11 21:08:00 to 19-JUN-11 21:08:00 (CST-6)
Location: ARAPAHOE
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 250.00K
Reported by: Storm Chaser

Hail in FURNAS, NEBRASKA
From 19-JUN-11 21:10:00 to 19-JUN-11 21:10:00 (CST-6)
Location: CAMBRIDGE
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 250.00K
Reported by: Law Enforcement

Hail in FURNAS, NEBRASKA
From 19-JUN-11 21:12:00 to 19-JUN-11 21:12:00 (CST-6)
Location: ARAPAHOE
Magnitude: 2.50 
Property damage: 25.00K
Crop damage: 250.00K
Reported by: Storm Chaser

Hail in FURNAS, NEBRASKA
From 19-JUN-11 21:13:00 to 19-JUN-11 21:13:00 (CST-6)
Location: EDISON
Magnitude: 1.50 
Property damage: 10.00K
Crop damage: 250.00K
Reported by: Emergency Manager

Thunderstorm Wind in FURNAS, NEBRASKA
From 19-JUN-11 20:25:00 to 19-JUN-11 20:25:00 (CST-6)
Location: ARAPAHOE ARPT
Magnitude: 61.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts were estimated at 70 MPH, resulting in significant damage to a garage and barn.  Trees of 1 to 2 feet in diameter, and power lines, were blown down.

Hail in FURNAS, NEBRASKA
From 19-JUN-11 21:30:00 to 19-JUN-11 21:30:00 (CST-6)
Location: OXFORD
Magnitude: 2.50 
Property damage: 25.00K
Crop damage: 500.00K
Reported by: COOP Observer

Hail in HARLAN, NEBRASKA
From 19-JUN-11 21:37:00 to 19-JUN-11 21:37:00 (CST-6)
Location: RAGAN
Magnitude: 1.50 
Property damage: 15.00K
Crop damage: 250.00K
Reported by: Emergency Manager

Hail in PHELPS, NEBRASKA
From 19-JUN-11 22:00:00 to 19-JUN-11 22:15:00 (CST-6)
Location: HOLDREGE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 1.00M
Reported by: Newspaper

Hail up to the size of pennies fell across the area, resulting in some crop damage.

Hail in HOWARD, NEBRASKA
From 19-JUN-11 22:40:00 to 19-JUN-11 22:40:00 (CST-6)
Location: ELBA
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 250.00K
Reported by: CoCoRaHS

Hail in HOWARD, NEBRASKA
From 19-JUN-11 22:53:00 to 19-JUN-11 22:53:00 (CST-6)
Location: COTESFIELD
Magnitude: 2.50 
Property damage: 50.00K
Crop damage: 500.00K
Reported by: Law Enforcement

Thunderstorm Wind in MERRICK, NEBRASKA
From 19-JUN-11 23:25:00 to 19-JUN-11 23:45:00 (CST-6)
Location: CLARKS
Magnitude: 70.00 EG
Property damage: 1.00M
Crop damage: 250.00K
Reported by: NWS Storm Survey

Wind gusts were estimated to be as high as 80 MPH.  Along this path, an old grain elevator was destroyed, large trees branches were blown down, irrigation pivots were overturned, and a couple of power poles were broken.

Thunderstorm Wind in HOWARD, NEBRASKA
From 19-JUN-11 23:35:00 to 19-JUN-11 23:35:00 (CST-6)
Location: ST PAUL
Magnitude: 52.00 EG
Property damage: 50.00K
Crop damage: 250.00K
Reported by: COOP Observer

Wind gusts were estimated at 60 MPH, knocking down small tree limbs.  Wind was accompanied by pea to penny size hail.

Hail in FURNAS, NEBRASKA
From 19-JUN-11 23:46:00 to 19-JUN-11 23:46:00 (CST-6)
Location: CAMBRIDGE
Magnitude: 2.75 
Property damage: 75.00K
Crop damage: 500.00K
Reported by: County Official

Hail in GOSPER, NEBRASKA
From 20-JUN-11 00:15:00 to 20-JUN-11 00:15:00 (CST-6)
Location: ELWOOD
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in GOSPER, NEBRASKA
From 20-JUN-11 00:17:00 to 20-JUN-11 00:17:00 (CST-6)
Location: ELWOOD
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in GOSPER, NEBRASKA
From 20-JUN-11 00:16:00 to 20-JUN-11 00:16:00 (CST-6)
Location: ELWOOD
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in GREELEY, NEBRASKA
From 20-JUN-11 00:30:00 to 20-JUN-11 00:50:00 (CST-6)
Location: SCOTIA
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 100.00K
Reported by: Trained Spotter

Hail in MERRICK, NEBRASKA
From 20-JUN-11 01:02:00 to 20-JUN-11 01:02:00 (CST-6)
Location: SILVER CREEK
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 100.00K
Reported by: Law Enforcement

Hail in POLK, NEBRASKA
From 20-JUN-11 01:05:00 to 20-JUN-11 01:05:00 (CST-6)
Location: SHELBY
Magnitude: 2.75 
Property damage: 50.00K
Crop damage: 500.00K
Reported by: Public

Hail in POLK, NEBRASKA
From 20-JUN-11 01:20:00 to 20-JUN-11 01:20:00 (CST-6)
Location: SHELBY
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 250.00K
Reported by: Public