Unseasonably warm air, with afternoon temperatures reaching into the 60s and low 70s, and a surge of moisture from the Gulf of Mexico interacted with a slow moving cold front during the afternoon and evening hours of January 30th, resulting in strong low-topped showers and thunderstorms and widespread heavy rainfall. Despite weak CAPE associated with the frontal passage, low level wind shear was in excess of 60 knots across the region, which made for strong squall lines of shower activity, often with strong winds but little to no lightning. Precipitable water values were observed to be in the 1.0 to 1.5 inch range, which is extremely high for January across the Appalachians and the nearby Piedmont region. To add to the flooding threat, ground conditions were already saturated from recent rain and snow during the days and weeks preceding the event.
The following is a list of rainfall totals, in inches, that fell across portions of southeast West Virginia:
- Greenbrier County - | 2.45 McRoss 3 E COOP,| 2.36 4 SE Ronceverte CCR,| 2.05 Lewisburg 3 N COOP,| 2.04 Williamsburg IFLOWS,| 1.96 Alderson IFLOWS,| 1.92 Meadow Bluff IFLOWS,| 1.90 White Sulphur Springs DCP,| 1.86 White Sulphur Springs COOP,| 1.63 Brushy Mountain IFLOWS.
- Mercer County - | 2.08 Bluefield COOP,| 1.94 Eads Mill IFLOWS,| 1.91 Egeria IFLOWS,| 1.79 Bluefield IFLOWS,| 1.74 Bluefield FAA Airport,| 1.72 Arista IFLOWS,| 1.67 Mataoka IFLOWS,| 1.55 Bramwell IFLOWS.
- Monroe County - | 2.50 Rock Camp DCP,| 1.40 Ballard IFLOWS,| 1.39 Union IFLOWS.
- Summers County - | 2.18 Bluestone River at Pipestem,| 2.14 Pipestem RAWS,| 2.13 Pipestem Knob IFLOWS,| 2.10 Alderson,| 2.04 Keeney Knob IFLOWS,| 1.95 Bluestone Lake COOP.