Hail — Adams, Nebraska

2017-06-13 · near Holstein, Adams, Nebraska

Event narrative

Hail ranged from quarter to tennis ball size.

Wider weather episode

In what had been a slower-than-average severe weather season up to this point within South Central Nebraska, this Tuesday evening event ended up being one of the most significant episodes of the 2017 season. Primarily between 6:30-10:30 p.m. CDT, a rash of severe storms consisting of semi-discrete supercells and quasi-linear clusters yielded dozens of large hail and damaging wind reports, including hail to at least tennis ball size in/very near both Grand Island and Hastings. Despite its significance, this was not a tremendously widespread event in terms of areal coverage, as the vast majority of severe weather focused within a relatively narrow, 30-50 mile wide corridor centered roughly through the Red Cloud-Hastings-Grand Island-Aurora-Osceola areas.

Severe reports were split fairly evenly between hail and damaging winds. Hail was the bigger issue in western portions of the affected areas, with wind damage more of a factor farther east. Focusing first on hail, one of the biggest stories involved both the Grand Island and Hastings areas getting pelted within the same hour. In Grand Island, much of the city saw stones ranging from quarter to tennis ball size. In Hastings, the majority of the city itself observed quarter to golf ball size hail. However, a corridor running from just a few miles southwest-through-west of the city limits endured larger hail up to baseball size. As for damaging winds, the overall-worst impacts focused within counties east of Highway 281. In west-central Polk County, a personal weather station clocked an unofficial gust of 92 MPH, with gusts of at least 70 MPH also reported in the Clay Center, Bradshaw and Guide Rock areas. Many other locations had estimated or measured gusts in the 58-65 MPH range. Needless to say, there was a considerable amount of mainly minor tree and structural damage, including within the communities of Osceola, Shelby and Hordville. Fortunately, no tornadoes were reported, although storm chasers witnessed gustnado activity along the leading edge of surging outflow. Rainfall-wise, most places received no more than 1-2 from the evening of the 13th into the early morning of the 14th. However, the primary higher exception focused within southeastern Franklin and southwestern Webster counties, where a localized maximum of 3-4 fell in the Inavale and Riverton areas.

Breaking down timing, the first severe storms of the evening erupted along a fairly narrow, southwest-northeast corridor between 6:30-7:30 p.m. CDT, during which time both Grand Island and Hastings were hit with the large hail. Over the following hour, damaging winds became the main issue as outflow surged east, especially within Polk, Hamilton and York counties. Then, between 8:30-10:30 p.m. CDT, the initial wave of severe storms exited northeast portions of the local area while a second round erupted farther south, mainly impacting Webster, Clay and Nuckolls counties. Although the severe weather threat ended by 11 p.m. CDT, quite a bit of thunderstorm activity redeveloped through the night within various portions of South Central Nebraska.

In the mid-upper levels, this event was driven by a shortwave trough swinging east through the Central Plains, to the southeast of its parent closed low centered over Montana. At the surface, early evening storm initiation clearly focused along a composite stationary front/dryline stretched north-south through central Nebraska, attendant to a surface low pressure center that deepened to 998 millibars during the late afternoon hours. To the east of this dryline, afternoon high temperatures well into the 90s F combined with dewpoints in the upper 50s-mid 60s resulted in mixed-layer CAPE values of at least 2000-3000 J/kg, in the presence of 0-6 kilometer shear increasing to 40-50 knots as the evening progressed.

View location on OpenStreetMap → (40.4905, -98.6769)

Source: NOAA Storm Events Database, event_id 695419. Narrative written by the NWS forecast office that issued the report.