Storm Events Database

Storm Events Database

Event Details

Event Hail
Magnitude 1.00 in.
State NEBRASKA
County/Area HOWARD
WFO GID
Begin Date 05/12/2011 16:19:00 CST-6
Begin Range 0
Begin Azimuth N
Begin Location ST LIBORY
Begin Lat/Lon 41.08/-98.37
End Date 05/12/2011 16:19:00 CST-6
Deaths Direct/Indirect 0/0 (fatality details below, when available...)
Injuries Direct/Indirect 0/0
Property Damage 0.00K
Crop Damage 0.00K
Episode Narrative For the second day in a row, severe thunderstorms pounded mainly eastern portions of South Central Nebraska, including many of the same areas affected on the 11th. The majority of severe weather focused near to 30 miles north of the Interstate 80 corridor in Hall, Merrick, Hamilton, Polk and York Counties. Brief, short-track tornadoes also occurred for the second day in a row, with three confirmed EF0 tornadoes. This included one tornado between Aurora and Giltner, and two others a few miles west of Stromsburg. No damage was reported from these brief touchdowns. In addition, the afternoon and early evening featured numerous reports of large hail, along with torrential rainfall and localized flooding. The largest reported hail of 3 inches in diameter occurred just south of Exeter in Fillmore County. Even several hours after severe storms ended across the area, strong northwest winds developed behind the cold front in the evening as the pressure gradient increased, including a measured 58 MPH gust at the York airport.

This Thursday featured a fairly classic spring setup for severe weather, with a nearly vertically-stacked low pressure system slowly lumbering east near the Nebraska and Kansas border both at the surface and aloft. A nearly stationary surface front arced northeast and east from the low roughly along the Interstate 80 corridor. Meanwhile, a modest dryline swept into the area from the southwest, and a cold front gradually worked southward in the wake of the slow-moving surface low. The combination of these multiple boundaries, along with considerable early afternoon sunshine and the close proximity of the mid-level low pressure system, effectively made this a cold core severe weather situation. While the first strong storm of the day fired up by mid-afternoon in Furnas County nearly directly underneath the mid-level low, the focus quickly turned northeast of the low, with the first severe storms developing in Sherman County around 330 PM. Over the course of the next several hours, severe storms then developed eastward down the Interstate 80 corridor, and southward along the Highway 81 corridor into Fillmore County before gradually slipping eastward out of the area. By late afternoon, the mesoscale environment in the vicinity of the brief tornadoes in Polk County featured 1500 J/kg mixed-layer CAPE, and around 20 knots of low level 0-1km bulk shear.

Heavy rainfall and flooding were also an issue, especially across a narrow corridor north of Interstate 80. As the severe storms trained over this area, 24-hour rainfall totals of 1.5 to over 4 inches were reported across parts of southern Sherman, southern Howard, far northern Hall, Merrick, northern Hamilton, southwest Polk and northwest York Counties. Some of these areas had just received 1-2 inches of rain in severe storms the day before, thus pushing 48-hour rainfall totals into the 4-6 inch range. The town of Polk reported one of the highest 24-hour and 48-hour rainfall amounts, at 4.34 and 6.12 inches, respectively. This resulted in extensive lowland flooding of fields and small creeks, with water also covering numerous roadways. Even a few days after the rainfall, flooding continued along the Big Blue River in Polk County.
Event Narrative


All events for this episode:

Location County/Zone St. Date Time T.Z. Type Mag Dth Inj PrD CrD
Totals: 0 0 350.00K 3.000M
CAMBRIDGE FURNAS CO. NE 05/12/2011 13:40 CST-6 Hail 0.88 in. 0 0 0.00K 0.00K
HAZARD SHERMAN CO. NE 05/12/2011 14:36 CST-6 Hail 0.75 in. 0 0 0.00K 0.00K
ROCKVILLE SHERMAN CO. NE 05/12/2011 15:07 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
BENEDICT YORK CO. NE 05/12/2011 15:10 CST-6 Hail 1.25 in. 0 0 0.00K 0.00K
ROCKVILLE SHERMAN CO. NE 05/12/2011 15:24 CST-6 Hail 0.88 in. 0 0 0.00K 0.00K
ROCKVILLE SHERMAN CO. NE 05/12/2011 15:28 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
RAVENNA BUFFALO CO. NE 05/12/2011 15:32 CST-6 Hail 1.50 in. 0 0 0.00K 0.00K
GILTNER HAMILTON CO. NE 05/12/2011 15:46 CST-6 Tornado EF0 0 0 0.00K 0.00K
GRAND IS HALL CO. NE 05/12/2011 15:51 CST-6 Hail 0.75 in. 0 0 0.00K 0.00K
RAVENNA BUFFALO CO. NE 05/12/2011 15:52 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
RAVENNA BUFFALO CO. NE 05/12/2011 15:55 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
ST LIBORY HOWARD CO. NE 05/12/2011 16:19 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
POLK POLK CO. NE 05/12/2011 16:20 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
STROMSBURG POLK CO. NE 05/12/2011 16:33 CST-6 Tornado EF0 0 0 0.00K 0.00K
SWEDEHOME POLK CO. NE 05/12/2011 16:36 CST-6 Tornado EF0 0 0 0.00K 0.00K
CHAPMAN MERRICK CO. NE 05/12/2011 16:37 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
GRAND IS HALL CO. NE 05/12/2011 16:43 CST-6 Hail 0.88 in. 0 0 0.00K 0.00K
ST LIBORY HOWARD CO. NE 05/12/2011 16:45 CST-6 Flash Flood 0 0 25.00K 500.00K
(GRI)GRAND IS RGNL A HALL CO. NE 05/12/2011 16:45 CST-6 Flash Flood 0 0 25.00K 500.00K
WORMS MERRICK CO. NE 05/12/2011 16:45 CST-6 Flash Flood 0 0 25.00K 500.00K
STROMSBURG POLK CO. NE 05/12/2011 17:30 CST-6 Hail 1.75 in. 0 0 25.00K 0.00K
ARBORVILLE YORK CO. NE 05/12/2011 17:55 CST-6 Flash Flood 0 0 25.00K 500.00K
HORDVILLE HAMILTON CO. NE 05/12/2011 17:55 CST-6 Flash Flood 0 0 25.00K 500.00K
POLK POLK CO. NE 05/12/2011 17:55 CST-6 Flash Flood 0 0 25.00K 500.00K
FAIRMONT FILLMORE CO. NE 05/12/2011 18:12 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
MC COOL JCT YORK CO. NE 05/12/2011 18:23 CST-6 Hail 0.88 in. 0 0 0.00K 0.00K
YORK YORK CO. NE 05/12/2011 18:30 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
FAIRMONT FILLMORE CO. NE 05/12/2011 18:30 CST-6 Hail 1.50 in. 0 0 25.00K 0.00K
EXETER FILLMORE CO. NE 05/12/2011 18:35 CST-6 Hail 1.50 in. 0 0 25.00K 0.00K
EXETER FILLMORE CO. NE 05/12/2011 18:35 CST-6 Hail 3.00 in. 0 0 100.00K 0.00K
BRADSHAW YORK CO. NE 05/12/2011 18:44 CST-6 Hail 1.50 in. 0 0 25.00K 0.00K
OSCEOLA POLK CO. NE 05/12/2011 18:53 CST-6 Hail 1.00 in. 0 0 0.00K 0.00K
YORK (ZONE) YORK (ZONE) NE 05/12/2011 22:55 CST-6 High Wind 50 kts. MG 0 0 0.00K 0.00K
Totals: 0 0 350.00K 3.000M