Complex sentence: The tornado moved into Morgan County and threatened the Decatur area, resulting with the NWS in Huntsville issuing a tornado emergency (the fifth in the outbreak) for Morgan County and southern Limestone County.
Split into simpler sentences: The tornado moved into Morgan County and threatened the Decatur area. Due to this, the NWS in Huntsville issued a tornado emergency, the fifth in the outbreak, for Morgan County and southern Limestone County.