Re Saturday's Tornado Outbreak

I'm sure most everyone is aware, by now, of the deadly tornado outbreak that occurred Saturday April 24th east of the Mississippi and south of the Ohio Rivers. We've been away over the weekend and I have just taken a look at the charts for this event; I can't resist commenting.

------------------------------------------------------------------------------

While the general setting and likelihood of a significant severe thunderstorm outbreak was synoptically evident, as was mentioned on the MAPS talk board, there were many complicating factors. The situation had been characterized by widespread nighttime and early morning thunderstorms, bow echoes, and small storm complexes before the Storm Prediction Center's (SPC) 1200 UTC morning outlook was issued (top). There were many mesoscale and storm-scale features (outflows, debris clouds, old anvils, etc.) that could have disrupted, or modified, the intense large-scale setting. The long-lived, supercell thunderstorm that produced the tornado that struck Yazoo City, Mississippi, appeared to develop around 13 UTC in western Louisiana and then moved rapidly east-northeastward at around 60+ mph. The preliminary severe storm and tornado reports are shown in the bottom graphic, which clearly indicates that there were apparently several long-lived, or cyclic, supercell thunderstorms producing very long damage paths. Note that the High and Moderate risk areas verified extremely well, with the Yazoo City storm tracking right through the center of the High Risk area. Kudos to the forecasters at the SPC!