Thunderstorm Wind in Nevada County, Arkansas

Several trees uprooted at White Oak Lake State Park southeast of Bluff City near the Ouachita County line.

Strong to severe thunderstorms developed along the Middle Red River Valley during the early morning hours on May 24th. These thunderstorms intensified in vicinity of deeper theta-e advection via the low-level jet on the southern fringe of a residual cold pool. The convective environment supported increasing storm organization, with effective shear around 50 knots. Strong to severe thunderstorm potential accompanied the more discrete updrafts that managed to develop as convection became fairly well-organized, aided by persistent low-level warm advection within a thermodynamic environment characteristic of 2000 to 3000 J/kg mixed-layer CAPE. As a result, an isolated tornado occurred in Sevier County during the pre-dawn hours.

Later in the day, a cluster of strong to severe thunderstorms developed across the same general area during the late afternoon through the evening hours. Ahead of this convection, surface dewpoints were in the middle to upper 70s while MLCAPE values ranged from the 3000 to 4000 J/kg range, as observed by nearby 00Z soundings. In addition, 0-6 km shear was roughly 45 knots with 0-3 km storm-relative helicity near 225 m2/s2. This near storm environment also had 700-500 mb lapse rates near 7.5 C/km, supportive of the potential for supercells containing large hail and damaging wind gusts. As a result, several reports of damaging wind gusts were received across Southwest Arkansas along with one hail report in Union County.