Tornadoes in Hurricane Harvey: Documentation and Environmental Analysis

During the seven-day period of 25‒31 August 2017, Hurricane Harvey and its remnants spawned 52 recorded tornadoes, while the system moved very slowly across southeast Texas, the Mississippi Delta region, and the Mid-South. Because of both its unique longevity as a tornado-producing TC, and the presence of favorable environmental conditions over that weeklong span, Harvey’s tornado count was above average for tropical cyclones in the current (1995‒2017) era of such records. Harvey’s tornadoes, though conforming well to climatological spatial distribution with respect to TC center, showed a decided preference for morning occurrence, compared to typical afternoon peaks for TC tornadoes as a whole. Harvey also exhibited great day-to-day variability in tornado activity. Though a distant secondary threat to the system’s record heavy rainfall and flooding on the West Gulf Coastal Plain, Harvey’s tornadoes still threatened life and property across a broad cumulative area, and were the subject of a protracted series of challenging forecasts. We will document the system’s spatiotemporal tornado distribution with comparisons to TC-tornado climatology, and analyze the environment for Harvey‘s supercells from the synoptic scale to mesoscale.