The mid-late afternoon hours on this Tuesday featured a smattering of strong to marginally severe thunderstorms primarily within the southwestern quadrant of South Central Nebraska (generally near/south of Interstate 80 and west of Highway 281). Within this area, there were a handful of severe-criteria wind gust and/or wind damage reports, including estimated 60 MPH gusts with four-inch tree limbs down eight miles south of Elwood, some minor tree damage in Red Cloud and also some limited tree damage and a power line down in Gibbon. There were no reports of large hail. Although there was no ground-truth confirmation of flooding, locally heavy rain in excess of three inches drenched portions of southeastern Harlan and far southwestern Franklin counties due to a combination of not only afternoon convection, but also redevelopment of a few strong storms during the night between 9 p.m. and 3 a.m. CDT. Within this small zone, event-total rain totals featured 3.75 two miles northwest of Republican City (NeRAIN observer) and 3.37 at Naponee (NWS coop observer).
Focusing on timing, weak convection got underway early in the afternoon within extreme western portions of South Central Nebraska. However, it took a few hours for strong to severe activity initially over southwestern Nebraska to create a sufficient cold pool and push eastward into the local area between 3-4 p.m. CDT in the form of a north-to-south oriented bowing line segment. While this initial surge of winds resulted in the damage reports from Gosper and Buffalo counties, newly developing multicell storms soon blossomed farther east within counties along the state line, including the one responsible for tree damage in Red Cloud. While there were no reports of severe weather after 4:30 p.m. CDT, fairly widespread coverage of showers and storms persisted within much of South Central Nebraska through around 8 p.m. CDT. Beyond sunset, isolated to scattered thunderstorms redeveloped over several state-line counties along the nose of a modest low level jet, producing the aforementioned heavy downpours in Harlan/Franklin counties. Finally, by 6 a.m. CDT, the vast majority of South Central Nebraska was rain-free. In the larger scale of the mid-upper levels, this event was instigated by a slow-moving, elongated shortwave trough gradually sinking from northwest-to-southeast through the Central Plains. At the surface, afternoon convection intensified just to the north of a quasi-stationary front stretched west-to-east across northern Kansas. Around the time severe storms first entered the local area temperatures were only in the 70s F, but the mesoscale environment contained around 1500 J/kg mixed-layer CAPE and deep layer wind shear of 30-35 knots.

Heavy Rain in FRANKLIN, NEBRASKA
From 04-AUG-15 14:00:00 to 05-AUG-15 06:00:00 (CST-6)
Location: NAPONEE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24 hour rainfall total of 3.37 inches occurred in Naponee. Rain began in the early afternoon on August 4th.

Heavy Rain in HARLAN, NEBRASKA
From 04-AUG-15 13:00:00 to 05-AUG-15 06:00:00 (CST-6)
Location: REPUBLICAN CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24-hour rainfall total of 3.75 inches occurred two miles northwest of Republican City. This was recorded by an NeRAIN observer (Nebraska Rainfall Assessment and Information Network). In addition, the NWS coop observer at Harlan County Lake tallied 3.34. Rain began during the early afternoon on August 4th.

Thunderstorm Wind in GOSPER, NEBRASKA
From 04-AUG-15 14:31:00 to 04-AUG-15 14:31:00 (CST-6)
Location: ELWOOD
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

Tree limbs that were about four inches in diameter were blown down due to thunderstorm wind gusts.

Thunderstorm Wind in WEBSTER, NEBRASKA
From 04-AUG-15 15:19:00 to 04-AUG-15 15:19:00 (CST-6)
Location: RED CLOUD
Magnitude: 52.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several small branches were down around town, along with half of a larger tree, due to an apparent microburst.

Thunderstorm Wind in BUFFALO, NEBRASKA
From 04-AUG-15 16:05:00 to 04-AUG-15 16:05:00 (CST-6)
Location: GIBBON
Magnitude: 52.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Multiple eight-inch diameter tree branches were blown down, and consequently knocked down a power line in Gibbon.