What makes you think it is data vs a radar? I am not saying it is not data, wihtout more description or a recording I simply do not know, but the duration you describe and the width you describe is one that is pretty common for a couple radars that fill the 27500 to 28000 area. Maybe tomorrow (if I remember) I will grab a vid of the radars, so you can compare that to what you are seeing / hearing.
T!