Complex sentence: Including the 2001 tornadoes, only seven October tornadoes had been recorded in the NWS Detroit county warning area prior to the 2007 outbreak; by comparison, as of October 19, NWS Detroit had confirmed five tornadoes in its coverage area from this outbreak.
Split into simpler sentences: Including the 2001 tornadoes, only seven October tornadoes had been recorded in the NWS Detroit county warning area prior to the 2007 outbreak. By comparison, NWS Detroit had confirmed five tornadoes in its coverage area from this outbreak.