Thunderstorm Wind in Clay County, Georgia

Trees were blown down along Highway 37.

This event featured all modes of severe weather in our forecast area, including 13 tornadoes, numerous reports of straight-line wind damage, and even large hail. The 13 tornadoes consisted of 1 EF3, 2 EF2s, 6 EF1s, and 4 EF0s. This is a very high number of tornadoes for our forecast area for a single event. This compares with 7 tornadoes in the 1/22/17 event, 8 tornadoes in the 1/2/17 event, and 10 tornadoes in the 3/1/07 event. This may have been the most tornadoes for a single event in our area since the Hurricane Ivan tornadoes back in 2004. The synoptic pattern was characterized by a fast-moving upper trough through relatively zonal flow. The forecast area was under the favorable right entrance region of the upper jet with lots of upper level divergence. An 850 mb jet near or in excess of 50 knots was also present, which is another typical ingredient for severe weather in this part of the country in the cool season. Cool season levels of shear (0-1 km shear > 30 knots and 0-6 km shear > 50 knots) were overlaid with moderate levels of instability (SBCAPE 1500 j/kg), as opposed to more typical winter SBCAPE < 500 j/kg. Without this strong low-level jet, the low-level shear values would have been weaker and we would have probably seen less tornadoes.