A Synoptic Perspective of the Record 1-2 May 2010 Mid-South Heavy Precipitation Event

During 1–2 May 2010, a series of strong thunderstorms led to 41, 57, and 43 tornado, severe wind, and severe hail reports, respectively, across portions of the southern United States. In addition to severe weather, these storms also distributed recordsetting rainfall amounts across the mid-South region, which contributed to historic flooding across portions of central and western Kentucky and Tennessee (Fig. 1). This heavy precipitation event was sampled by multiple surface observational networks, including (but not limited to) 48 research-grade automated stations from the Kentucky Mesonet (www.kymesonet .org), first-order automated stations from the National Weather Service (NWS; www.ncdc.noaa.gov /oa/ncdc.html), and Community Collaborative Rain, Hail and Snow Network Stations (CoCoRaHS), some of which recorded more than 350 mm of rain during the two-day period across portions of the region (Fig. 2). The Kentucky Mesonet station in Bowling Green recorded the greatest rainfall intensity for the state, with 8.38 mm during a 5-min period, and 50.8 mm during an hour (Fig. 3). Bowling Green, Kentucky, also received the greatest amount of rainfall in the state with 258 mm, which broke the previous alltime two-day precipitation record for the state of 211 mm set during 6–7 December 1924. Moreover, Bowling Green received more than 120 mm each day, which ranks as the sixth (124.9 mm) and eighth (120.6 mm) greatest daily rainfall totals in Kentucky since 1900. According to the NWS office in Nashville, Tennessee, Camden, Tennessee, received the most rainfall in the state with 493 mm, which also set a new precipitation record. One CoCoRaHS station in Camden reported nearly 338 mm during a 24-h period, which was 7.62 mm shy of the all-time 24-h precipitation record for Tennessee. Nashville received more than 150 mm each day of the event, which ranked as the third-most (158.2 mm) and greatest (184.2 mm) 24-h rainfall accumulations of all time, and subsequently marked the wettest May on record for the city. In fact, many prior rainfall records that fell to the 1–2 May 2010 extratropical heavy precipitation event were originally produced by systems that were tropical in origin (e.g., Hurricanes Frederic and Katrina in 1979 and 2005, respectively)