Although only three of the 24 counties in this South Central Nebraska area measured widespread snow accumulation of 3+ inches, several other counties experienced some unusual and memorable holiday weather between the late afternoon of Christmas Day 2015 and the early morning of Saturday the 26th. Most notably in the unusual department, a fairly narrow axis of legitimate elevated thunderstorms blossomed between 5-9 PM from Franklin/Webster counties northeastward through the Hastings-Grand Island-Aurora-York-Osceola areas. These storms, which featured frequent lightning at times, produced a varied mix of sleet, graupel (snow pellets), freezing rain and light snow. While most places saw fairly minimal accumulation of this wintry mix, the NWS office in Hastings tallied 1.1 of graupel as thunderstorms persisted for nearly two hours. Needless to say, this event likely marked one of the only...if not the only...occurrence of Christmas thunderstorms in South Central Nebraska.
While elevated convection occurred mainly during the early evening hours in central and eastern portions of South Central Nebraska, the focus for precipitation later in the evening and into the late-night hours shifted to the north and west where slightly colder air aloft allowed plain snow to be the primary precipitation type. More specifically, a southwest-to-northeast oriented snow band overspread locations primarily northwest of a line from Beaver City-Kearney-Wolbach during the 9 PM-midnight time frame before eventually departing far northern counties such as Valley/Greeley between 3-5 AM on the 26th. While most counties within this snow zone accumulated no more than 1 to 2.5, a more concentrated swath of 3-5 targeted much of Sherman/Valley/Greeley counties. According to NWS cooperative observers, some of the highest totals featured: 4.5 at Ord, 3.5 at Arcadia and Loup City and 3.1 at Greeley. Fortunately, winds were not a major issue, averaging only 10-15 MPH from an east-northeast direction. In addition to the aforementioned round of convection and the primary snow band, there was yet another round of precipitation worthy of mention: mainly between 11 PM-4 AM, areas of steady light freezing drizzle developed within several of the same central and eastern counties that earlier had experienced thunderstorm activity. This freezing drizzle coated all elevated surfaces with a light glaze in places such as Hastings and Grand Island. However, somewhat ironically, many roadways did not become overly-slick from this freezing drizzle given that the ground was already textured by the earlier occurrence of graupel/snow pellets.
In the mid and upper levels, this complex, messy and memorable holiday weather event occurred under pronounced southwesterly flow aloft on the downstream side of an expansive, large-scale trough centered over the western United States. On the smaller scale, forcing was provided by a lead shortwave disturbance ejecting out from the parent trough through western Nebraska into South Dakota. In the lower levels at 850 millibars, precipitation development and intensity (especially the convection) was aided by a rather strong southeasterly low level jet that ramped up to around 40 knots and interacted with weak elevated instability. The complexity of the varied precipitation types over South Central Nebraska was very evident in the 850 millibar temperature gradient, as the 0 C line roughly bisected the heart of the area from southwest-to-northeast throughout this event, with southeastern counties averaging a few degrees above freezing at this level and northwestern counties a few degrees below freezing. Meanwhile, down at the surface, persistent easterly flow held all but the far southeast fringes of the area down in the 27-32 F range, promoting the various frozen precipitation types.

Winter Weather in SHERMAN, NEBRASKA
From 25-DEC-15 21:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A snowfall total of 3.5 inches occurred in Loup City. Also, an NeRAIN observer reported 3.0 four miles north of Litchfield.

Winter Weather in GREELEY, NEBRASKA
From 25-DEC-15 22:00:00 to 26-DEC-15 05:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A snowfall total of 3.1 inches occurred in Greeley.

Winter Weather in VALLEY, NEBRASKA
From 25-DEC-15 21:00:00 to 26-DEC-15 05:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A snowfall total of 4.5 inches occurred in Ord. Also, a snowfall total of 3.5 inches occurred in Arcadia.

Winter Weather in ADAMS, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in CLAY, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in HALL, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in HAMILTON, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in YORK, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in HOWARD, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in MERRICK, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in NANCE, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.

Winter Weather in POLK, NEBRASKA
From 25-DEC-15 17:00:00 to 26-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A varied mix of sleet, graupel (snow pellets), freezing rain/drizzle and light snow occurred within the county, along with rare December thunderstorm activity.