Flash Flood in McCurtain County, Oklahoma

High water covered the U.S. Highway 70 Bypass near Lynn Lane.

Scattered thunderstorms developed early in the morning on June 23rd within a zone of weak theta-e advection at 850 millibars, from Southwest Oklahoma into Northeast Texas. Rich boundary layer moisture as well as overall strong instability was in place across this region, along with effective deep-layer shear of 35-40 knots. Wind profiles indicated 850 millibar winds out of the south to southeast at around 25 knots, aiding in lift across the warm advection zone. As low-level winds veered and strengthened during the morning hours, forcing for ascent also increased. Slow-moving thunderstorms with heavy rainfall began to rapidly increase in this environment, even extending through the afternoon. Given the high precipitable water (PWAT) environment, localized strong downbursts also occurred with some of these storms. Widespread rainfall amounts of 2-6+ inches fell over Southern McCurtain County Oklahoma from the morning through the evening, contributing to areas of flash flooding. An isolated severe thunderstorm also developed over this area during the evening hours on the 23rd before diminishing. As a result, several reports of flash flooding were recorded across McCurtain County Oklahoma along with an isolated damaging wind report.