This was a unique Tuesday afternoon and evening of weather across South Central Nebraska. Following a lull of several hours in the wake of overnight severe thunderstorms that produced widespread large hail and damaging winds, winter collided with spring to produce showers and elevated thunderstorms with a varied mix of sleet, hail and freezing rain. This was all made possible by strong frontogenesis and easterly warm air advection evident at 850 millibars flowing over the top of a shallow, cold low level airmass featuring mid-afternoon surface temperatures only between the low-20s and low-30s across most of the area, or 30+ degrees below normal for the date. In addition to widespread accumulating sleet in many locations, hail ranging from dime to quarter size was reported across various parts of the 24-county area mainly between 130-600 PM CDT. This included hail stones to quarter size at Fullerton, and nickel size at Grand Island airport, in Benedict and near Hastings. To cite just one example of the unusual nature of this event, as nickel size hail was falling with thunderstorms in the Hastings area at 530 PM CDT, the surface temperature was 25 degrees and north winds were sustained around 25 MPH, producing a wind chill temperature around 10 degrees. Despite this very cold surface regime, elevated thunderstorms thrived in an environment featuring most unstable CAPE of 500-1000 J/kg and 30-50 knots of effective deep layer vertical wind shear.
Thunderstorms first broke out over counties west of Highway 281 between noon and 130 PM CDT, well to the west of a sharp synoptic cold front extending from extreme southeast Nebraska to south central Kansas. Through the rest of the afternoon and into the evening, multiple clusters and line segments of fast-moving elevated storms streamed north-northeast across areas mainly near and east of Highway 281, before finally exiting the local area east of the Highway 81 corridor around 9 PM CDT. On the synoptic scale aloft, this event occurred just downstream from a powerful, closed mid level low centered over Colorado, which anchored an expansive and highly-amplified longwave trough dominating the western half of the United States. The rapid increase in afternoon thunderstorm development was aided by the arrival of the exit region of a 100+ knot south-southwest jet streak evident at 300 millibars. As it turned out, the 9th marked the first of three consecutive notably cold April days across South Central Nebraska, as temperatures failed to exceed the mid-to-upper 30s through the 11th.

Hail in HALL, NEBRASKA
From 09-APR-13 12:30:00 to 09-APR-13 12:30:00 (CST-6)
Location: (GRI)GRAND IS RGNL A
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail the size of pea to nickel was reported.

Hail in NANCE, NEBRASKA
From 09-APR-13 13:10:00 to 09-APR-13 13:10:00 (CST-6)
Location: FULLERTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail the size of peas to quarters was completely covering the ground.

Hail in HARLAN, NEBRASKA
From 09-APR-13 13:50:00 to 09-APR-13 13:50:00 (CST-6)
Location: ALMA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, NEBRASKA
From 09-APR-13 16:30:00 to 09-APR-13 16:30:00 (CST-6)
Location: HASTINGS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in ADAMS, NEBRASKA
From 09-APR-13 17:11:00 to 09-APR-13 17:11:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Penny and dime size hail was reported.

Hail in YORK, NEBRASKA
From 09-APR-13 16:15:00 to 09-APR-13 16:20:00 (CST-6)
Location: BENEDICT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dime to nickel size hail fell for five minutes. Report from Nebraska Rainfall Assessment and Information Network.