An upper level low moved into the TN and OH Valley region and then into the Appalachians from Sunday evening, March 11th into Monday, March 12th. At the same time, a surface low pressure system tracked into the TN Valley and southern Appalachians before redeveloping over the Southeastern U.S. during the night and then off the coast of the Carolinas on Monday. Temperatures on Sunday the 11th were mild, reaching the upper 40s to mid 50s. However, the upper level low brought colder air into the region and was strong enough to allow rapid cooling of the atmosphere to near or just below the freezing mark in most locations in East KY between 11 PM EDT on March 11 and 3 AM EDT on March 12. The development of heavier snow bands occurred at the same time over central KY, and with the cooling moving into eastern KY overnight, affected portions of east central KY first. These bands then moved east and affected areas generally north of KY Highway 80 to near the Mountain Parkway corridor. Within the bands, snowfall rates of up to 2 inches per hour occurred, leading to an area of heavier amounts (see storm reports below).
By 10 AM EDT on Monday, widespread accumulating snow had occurred over most of eastern Kentucky with the final band of snow working across the area. The snow finally exited into Virginia and West Virginia around 1 PM EDT. By that time, the heavy, wet snowfall totals ranged from as little as a half of an inch in some locations near the TN border to about 8 inches in areas near the Daniel Boone National Forest. A few localized higher amounts nearing 10 inches were observed on ridgetops from the Daniel Boone National Forest west.
At the height of the storm, at least 12,000 customers in East KY were without power. Slick and slushy conditions led to a 40 vehicle pileup on Mountain Parkway in eastern Powell County, forcing the closure of the roadway between 1:30 AM and 2:30 AM EDT Sunday night. In addition to the falling snow, trees and limbs succumbed to the weight of the heavy wet snow and fell onto roadways. Although with temperatures near freezing, plowing and salting improved road conditions during the day on Monday. This process was slowed a bit as highway departments, first responders, and utility companies cleared snow, large limbs, and utility lines from roadways.
...Snowfall Reports from the Wet Snow Event By County and Location...
...Bath County...
1 W Owingsville              3.2 in
Owingsville                     2.0 in
...Breathitt County...
2 NW Haginsville             5.0 in
2 SE Keck                       4.5 in
1 SE Fivemile                  3.0 in
Lawson                           2.3 in
...Clay County...
Oneida                           1.0 in
...Elliott County...
3 N Stark                       2.0 in
...Estill County...
Cressy                           8.2 in
Irvine                            7.0 in
...Floyd County...
Bonanza                        2.8 in
Prestonsburg                 2.0 in
2 ENE Dotson                1.8 in
1 E Blue River               1.5 in
...Jackson County...
1 WSW Clover Bottom   8.0 in
Sandgap                      5.0 in
1 N Loam                     4.0 in
1 ESE Maulden             2.7 in
...Johnson County...
Thealka                       3.0 in
1 WSW Wittensville      2.5 in
...Knott County...
2 SW Bolyn                 2.5 in
1 S Hindman               1.8 in
...Lee County...
Yellow Rock                7.0 in
2 NNE Mount Olive      6.2 in
1 NE Belle Point          5.8 in
1 NNW Belle Point       4.7 in
Beattyville                  4.0 in
...Letcher County...
1 ENE Payne Gap        2.0 in
1 SSW Ermine            1.0 in
...Martin County...
2 SW Davella              3.0 in
2 E Inez                     2.0 in
...McCreary County...
1 S Stearns                0.2 in
...Menifee County...
Frenchburg                 7.0 in
...Montgomery County...
Oggs Station               4.0 in
Mount Sterling             3.0 in
...Morgan County...
Ezel                            6.5 in
West Liberty                4.0 in
...Perry County...
Hazard                       1.2 in
Rowdy                        1.0 in
Viper                          0.5 in
...Powell County...
2 SW Bowen               8.5 in
1 SSE Clay City           5.0 in
2 W Stanton               3.5 in
Powell Valley              3.5 in
...Pulaski County...
2 N Somerset             2.2 in
1 WNW Somerset       1.6 in
...Rockcastle County...
1 ESE Hiatt                 7.2 in
Maretburg                  5.8 in
Mount Vernon             3.5 in
...Rowan County...
2 SSE Farmers            1.5 in
1 NNE Gates               1.4 in
...Wayne County...
1 NNW Cabell              0.7 in
...Wolfe County...
Campton                     4.0 in
.

Heavy Snow in POWELL, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 07:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in WOLFE, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 06:09:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in MENIFEE, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 07:12:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in ESTILL, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 07:12:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in LEE, KENTUCKY
From 11-MAR-18 22:30:00 to 12-MAR-18 05:18:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in ROCKCASTLE, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 07:24:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in JACKSON, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy Snow in BREATHITT, KENTUCKY
From 11-MAR-18 23:00:00 to 12-MAR-18 03:50:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Snow in MONTGOMERY, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 04:28:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Winter Weather in JOHNSON, KENTUCKY
From 11-MAR-18 23:00:00 to 12-MAR-18 04:15:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Winter Weather in KNOTT, KENTUCKY
From 11-MAR-18 23:30:00 to 12-MAR-18 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Winter Weather in MARTIN, KENTUCKY
From 12-MAR-18 00:00:00 to 12-MAR-18 04:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Heavy Snow in MORGAN, KENTUCKY
From 11-MAR-18 23:00:00 to 12-MAR-18 04:37:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Winter Weather in BATH, KENTUCKY
From 11-MAR-18 22:00:00 to 12-MAR-18 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Winter Weather in FLOYD, KENTUCKY
From 11-MAR-18 23:30:00 to 12-MAR-18 04:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee