EF1 tornado in St. Tammany Parish, Louisiana

NWS ground survey confirmed an EF-1 tornado impacted areas near Bayou Cane and moved northeast across US Hwy 190 west of Lacombe, LA in St. Tammany Parish. The tornado touched down near the shore of Lake Pontchartrain or came ashore as a tornadic waterspout with evident damage to marsh vegetation and trees per high resolution satellite imagery. The tornado was at peak intensity west of Lemieux Blvd where ground surveyors observed a few snapped trees on Cane Bayou Access Trail. Additional tree damage occurred on private property including several uprooted trees and a few snapped trunks as well as visible damage to a shed. The tornado uprooted and partially snapped trees as it crossed the Tammany Trace Bike Trail. The tornado began to evidently weaken as it approached and crossed US Hwy 190 causing only minor tree damage north of the highway. The tornado is estimated to have lifted near Azalea St and Cane Bayou Ln.

A mesoscale convective system formed on the eastern side of Post-Tropical Storm Arthur on June 18th. Favorable low level winds allowed for multiple mini-supercells to form on the leading edge of the mesoscale convective system resulting in several tornadoes impacting the Houma and New Orleans metro areas. These tornadoes were rated as EF-0 and EF-1 events. Additionally, the mesoscale convective complex tapped into a region of deep tropical moisture with atmospheric moisture content well above normal levels for mid-June. This resulted in several significant flash flooding events in portions of the Houma and New Orleans metro areas including the cities of Houma, Kenner, and Slidell. Another area of heavy rainfall from thunderstorms formed over central Louisiana near the center of Post-Tropical Storm Arthur producing flash flooding in portions of Pointe Coupee Parish. Lingering moisture and weak upper level troughing associated with the slow moving remnants of Post-Tropical Storm Arthur produced additional thunderstorm activity on June 19th. This activity was focused in metro New Orleans where a brief EF-0 tornado developed in the community of Arabi. On June 20th, another band of thunderstorms developed along a lingering boundary stretching from coastal Louisiana toward New Orleans. This band of thunderstorms produced heavy rainfall and impacted portions of the Houma and New Orleans metro areas producing a few flash flooding events in Houma, Destrehan, and Kenner.