Overview of the 7 May 2000 extreme rain event in Missouri

A synopsis and mesoscale analysis of the extreme rain event in east central Missouri on the night of 6-7 May 2000 that generated an estimated 14 in of rainfall in 12 h will be given. This event was poorly predicted, thus warranting further scrutiny. Of the well-recognized synoptic flash flood regimes that can occur (Maddox et al. 1979), none adequately capture the nature of this particular system. Although the quasi-stationary nature of the convection in this event was attributed to the presence of an outflow boundary in the popular media, this event appears to have been more frontal than meso-high in nature, at least early in its evolution. Hourly surface analyses (which include additional observations from Ag Extension network stations in Missouri) fail to show any surface outflow, even when a MCS motion is subtracted from the observed flow field. Moreover, the deep moisture present over Missouri at the time likely inhibited the creation of a mesohigh of any appreciable strength (Corfidi 1998). Instead, strong inflow (relative to the weak mesohigh) focused moisture convergence along the southern rim of the MCS.