A few rounds of convection affected parts of South Central Nebraska on this Friday, one earlier in the day that produced locally heavy rainfall in far-eastern counties and another later in the afternoon that featured an isolated severe storm over Hall County. Starting with the later round, a small cluster of fairly weak storms started developing in northern portions of the area (primarily Greeley-Nance-Howard counties) at mid-day, slowly sinking southward. As time went by, afternoon heating/destabilization led to intensification along the southwest flank of this storm cluster, resulting in two small severe storms that merged together as they drifted southward through Hall County between 3 pm and 430 pm CDT. There were a few reports of quarter size hail along with estimated 60 MPH gusts just southwest of Grand Island, but this storm steadily weakened and dissipated as it crossed eastern Adams County. Later in the evening, a few more strong storms rumbled into northwestern counties such as Valley and Greeley, but they remained sub-severe. Turning back to earlier in the day, a rather narrow, north-south oriented line of non-severe storms initially blossomed near the Highway 81 corridor from Polk County southward into Thayer County between 730-900 am CDT and persisted for several hours before dissipating early in the afternoon. Though most affected areas received less than 2 inches of rain, a particularly intense and narrow band set up directly over Osceola where the NWS cooperative observer tallied 3.17, most of which fell in two hours between 830-1030 am CDT and promoted minor flooding in the area.
In the mid and upper levels, both rounds of convection were sparked by the passage of a shortwave trough slowly shifting east from central Nebraska into western Iowa over the course of the day. The early round of heavy-rain producing storms near Highway 81 focused along a convergent zone in the heart of the trough axis, while the isolated severe storm during the afternoon occurred within a northwesterly-flow regime just behind the departing mid level trough axis and also along a weak surface trough.  Although the mesoscale environment was not overly-supportive of severe weather, the combination of mixed-layer CAPE around 1000 J/kg and fairly weak 0-6 kilometer deep layer shear up to 30 knots proved sufficient enough for the brief, isolated threat.

Hail in HALL, NEBRASKA
From 29-AUG-14 15:01:00 to 29-AUG-14 15:01:00 (CST-6)
Location: ALDA
Magnitude: 1.00 
Property damage: 150.00K
Crop damage: 2.00M
Reported by: Public

Estimated wind gusts of 60 mph were also reported with the quarter size hail. This was reported by the general public driving on Interstate 80 and was relayed by law enforcement.

Thunderstorm Wind in HALL, NEBRASKA
From 29-AUG-14 15:01:00 to 29-AUG-14 15:01:00 (CST-6)
Location: ALDA
Magnitude: 52.00 EG
Property damage: 150.00K
Crop damage: 2.00M
Reported by: Public

Quarter size hail also occurred along with the estimated 60 mph wind gusts reported the public driving on Interstate 80. This report was relayed by law enforcement.

Hail in HALL, NEBRASKA
From 29-AUG-14 14:35:00 to 29-AUG-14 14:35:00 (CST-6)
Location: ALDA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Quarter size hail occurred near the intersection of Highway 30 and Engleman Road. This report was received via Facebook.

Heavy Rain in POLK, NEBRASKA
From 29-AUG-14 07:30:00 to 29-AUG-14 11:00:00 (CST-6)
Location: OSCEOLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An NWS cooperative observer reported a storm-total rainfall of 3.17 inches, the majority of which fell between 830-1030 am CDT. Law enforcement reported some minor flooding in the immediate Osceola area.