Although severe thunderstorm winds only affected a small portion of North Central Kansas on this Saturday evening, the community of Osborne took a direct hit around 10 p.m. CDT as a wall of 65-70 MPH gusts blasted through town. Notable tree damage resulted, including larger limbs and a few completely uprooted. An empty semi trailer at a local business was tipped over, and a number of power poles were either damaged or snapped. In addition, an airport outbuilding sustained damage and an abandoned mobile home lost most of its roof. In addition to various estimated wind reports, a KSU mesonet station near the north edge of Osborne measured a peak 68 MPH gust. Although wind damage was clearly the main story across town, up to quarter size hail was also reported, along with a quick deluge of 1.50-2.00 of rain. As supported by radar data, damaging winds likely only impacted a narrow corridor as this multicell storm peaked in intensity within no more than 5-10 miles southwest-through-northeast of Osborne, and had weakened considerably by the time it reached the Mitchell County line around 10:30 p.m. CDT.
This severe storm was not the first convection of the day within this six county North Central Kansas area. As early as 4-5 p.m. CDT, non-severe storms brushed into Mitchell County, splitting off the north edges of a more concentrated cluster of strong to severe storms centered just south of the local area. Then a few hours later, additional sub-severe activity flared up over parts of Rooks/Osborne counties. Between 9-10 p.m. CDT, some of this weaker convection merged with a stronger storm tracking northeast out of Ellis County, eventually producing the Osborne wind damage. Once this severe storm dissipated, only weak activity lingered thereafter, with all of North Central Kansas storm-free by 2 a.m. CDT. In the mid-upper levels, a seasonably-typical quasi-zonal flow pattern was in place over Kansas, containing weak, embedded shortwave disturbances along the northern periphery of a subtropical high centered over Texas. At the surface, afternoon/evening convection within northern and western Kansas was largely tied to convergence along a quasi-stationary front. Despite warm mid level air with 700-millibar temperatures running 12-14 C, the presence of a well-mixed, hot and moist airmass featuring afternoon temperatures in the 90s F and dewpoints generally between 65-70 F was enough to breach the cap and result in vigorous, outflow-dominant multicell storms. Around the time of the Osborne wind damage, mesoscale parameters featured at least 1000-2000 J/kg mixed-layer CAPE and around 30 knots of deep-layer wind shear.

Hail in OSBORNE, KANSAS
From 08-AUG-15 21:02:00 to 08-AUG-15 21:02:00 (CST-6)
Location: OSBORNE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in OSBORNE, KANSAS
From 08-AUG-15 20:55:00 to 08-AUG-15 21:05:00 (CST-6)
Location: OSBORNE
Magnitude: 59.00 MG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gusts were both estimated and measured between 65 and 70 MPH in the area. There was notable tree damage in Osborne, including larger limbs and a few uprooted trees. An empty semi trailer at a local business was tipped over. A number of power poles were either damaged or snapped. There was damage to an outbuilding located at the airport approximately 1 mile east of town. An abandoned mobile home lost the majority of its roof. The 68 MPH wind gusts was measured by a KSU mesonet site located 1 mile north-northwest of Osborne.