The largest tornado outbreak in the NWS Huntsville Weather and Forecast Office's County Warning Area began during the early morning hours of 27 April 2011 with the first of three successive waves of tornadic thunderstorms. A quasi-linear convective system and embedded mesoscale convective vortex were responsible for at least 15 tornadoes producing EF-1 and EF-2 damage during the early morning hours of the 27th. The tornadoes struck between 0901 UTC and 1218 UTC, in some cases very close to one another in both space and time. During this particular wave and subsequent waves of tornadoes, data from the Advanced Radar for Meteorological and Operational Research dual-polarimetric radar from the University of Alabama at Huntsville were interrogated, in addition to data from nearby WSR-88Ds. The Huntsville WFO issued 21 tornado warnings and eight severe thunderstorm warnings during this initial wave of storms.

This presentation will include a review of the synoptic and near storm environments, a comparison of radar data between the different radar systems, as well as warning decisions.