Two distinct rounds of severe weather affected South Central Nebraska on this Saturday, one during the very early morning hours, and another, more widespread event that rolled in during the mid to late evening hours. The first round of storms flared up around midnight, in a northwest-southeast corridor stretching from Dawson County to Franklin County. These storms initiated along a rather subtle low to mid level convergence zone, in a very unstable airmass featuring 4000-5000 J/kg most-unstable CAPE and 30-40 knots of deep-layer vertical wind shear. Severe weather reports included estimated wind gusts to 60 MPH, and hail up to quarter size, along with locally heavy rainfall.
Following a lull that lasted through the day, the evening hours brought one of the most significant severe weather episodes of the summer to the area, as a concentrated swath of damaging 60-90 MPH wind gusts swept eastward along and near the Interstate 80 corridor. These severe storms actually resulted from a merger between storms moving east from Southwest Nebraska, and other storms dropping south from North Central Nebraska. These initial storms developed in closer proximity to a surface cold front and trough axis, trailing southward from low pressure centered over the Dakotas. Around sunset, these smaller storm clusters merged as they entered Dawson and Buffalo Counties, quickly evolving into a forward-propagating mesoscale convective system (MCS) with damaging outflow winds. As storms first entered South Central Nebraska, the mesoscale environment featured 3000-4500 J/kg most-unstable CAPE, and around 30 knots of deep-layer vertical shear. Over the course of around 3 hours, wind damage was widespread near the Interstate 80 corridor, but especially within Buffalo County, where gusts estimated as high as 90 MPH resulted in numerous damage reports. To name just a few, these reports included a roof torn from a home, numerous grain bins damaged or destroyed, and a number of power poles snapped, causing power outages in the area.  Nebraska Public Power District estimated 32 miles of power lines and 218 individual power structures were blown down in the Buffalo County area. Multiple reports were also received of damage to area trees and crops. Farther east, winds were not quite as strong, but still maintained severe levels as gusts to 68 MPH were measured at the Hastings airport, and 61 MPH at the Aurora airport. In addition to severe winds, there were also a few reports of hail during the evening, with the largest being golf ball size north of Lexington.

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 21:25:00 to 17-JUL-10 21:30:00 (CST-6)
Location: MAJORS
Magnitude: 78.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

One home reported roof damage, numerous grain bins were either damaged or destroyed, and a number of power poles were snapped, causing power outages in the area.  Multiple reports were received of damage to area trees and crops.

Thunderstorm Wind in DAWSON, NEBRASKA
From 17-JUL-10 20:09:00 to 17-JUL-10 20:09:00 (CST-6)
Location: GOTHENBURG
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DAWSON, NEBRASKA
From 17-JUL-10 20:24:00 to 17-JUL-10 20:24:00 (CST-6)
Location: GOTHENBURG
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in DAWSON, NEBRASKA
From 17-JUL-10 20:31:00 to 17-JUL-10 20:31:00 (CST-6)
Location: (CZD)COZAD MUNI ARPT
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Wind gusts estimated at 70 MPH.

Hail in DAWSON, NEBRASKA
From 17-JUL-10 20:45:00 to 17-JUL-10 20:55:00 (CST-6)
Location: LEXINGTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Thunderstorm Wind in DAWSON, NEBRASKA
From 17-JUL-10 20:48:00 to 17-JUL-10 20:48:00 (CST-6)
Location: LEXINGTON
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Wind gusts estimated at 80 MPH.

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 20:52:00 to 17-JUL-10 20:52:00 (CST-6)
Location: KEARNEY
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 20:52:00 to 17-JUL-10 20:55:00 (CST-6)
Location: MILLER
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Wind gusts estimated at 70 MPH.

Hail in BUFFALO, NEBRASKA
From 17-JUL-10 20:59:00 to 17-JUL-10 20:59:00 (CST-6)
Location: MILLER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 21:15:00 to 17-JUL-10 21:15:00 (CST-6)
Location: KEARNEY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts estimated at 65 MPH.

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 21:22:00 to 17-JUL-10 21:22:00 (CST-6)
Location: AMHERST
Magnitude: 78.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts estimated at 90 MPH.

Thunderstorm Wind in ADAMS, NEBRASKA
From 17-JUL-10 21:41:00 to 17-JUL-10 21:41:00 (CST-6)
Location: PROSSER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts estimated at 60 MPH.

Thunderstorm Wind in ADAMS, NEBRASKA
From 17-JUL-10 21:41:00 to 17-JUL-10 21:41:00 (CST-6)
Location: KENESAW
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts estimated at 60 MPH.

Thunderstorm Wind in ADAMS, NEBRASKA
From 17-JUL-10 21:51:00 to 17-JUL-10 21:51:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in HAMILTON, NEBRASKA
From 17-JUL-10 22:12:00 to 17-JUL-10 22:12:00 (CST-6)
Location: AURORA MUNI ARPT
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in HAMILTON, NEBRASKA
From 17-JUL-10 22:30:00 to 17-JUL-10 22:30:00 (CST-6)
Location: AURORA MUNI ARPT
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in ADAMS, NEBRASKA
From 17-JUL-10 22:12:00 to 17-JUL-10 22:12:00 (CST-6)
Location: HASTINGS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts estimated at 60 MPH.

Thunderstorm Wind in HALL, NEBRASKA
From 17-JUL-10 22:17:00 to 17-JUL-10 22:17:00 (CST-6)
Location: (GRI)GRAND IS RGNL A
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in YORK, NEBRASKA
From 17-JUL-10 22:25:00 to 17-JUL-10 22:25:00 (CST-6)
Location: YORK
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DAWSON, NEBRASKA
From 16-JUL-10 23:01:00 to 16-JUL-10 23:01:00 (CST-6)
Location: LEXINGTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Thunderstorm Wind in BUFFALO, NEBRASKA
From 17-JUL-10 00:11:00 to 17-JUL-10 00:11:00 (CST-6)
Location: ELM CREEK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts estimated at 60 MPH.

Thunderstorm Wind in PHELPS, NEBRASKA
From 17-JUL-10 00:38:00 to 17-JUL-10 00:38:00 (CST-6)
Location: HOLDREGE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts estimated at 60 MPH.

Hail in PHELPS, NEBRASKA
From 17-JUL-10 00:41:00 to 17-JUL-10 00:41:00 (CST-6)
Location: HOLDREGE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PHELPS, NEBRASKA
From 17-JUL-10 00:51:00 to 17-JUL-10 00:51:00 (CST-6)
Location: HOLDREGE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PHELPS, NEBRASKA
From 17-JUL-10 00:57:00 to 17-JUL-10 00:57:00 (CST-6)
Location: FUNK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter