I need to stress that potentially significant straight line winds in excess of 70mph are the main threat tonight. That will NOT trigger the sirens, but it can be just as damaging (sometimes even moreso) than a small tornado. There could even be some isolated gusts over 80mph. Relying on the sirens alone isn't a good idea in general, but a particularly bad idea tonight.
are you referring to the Huntsville area I assume from your location or just in general event wide?