Many communities have installed outdoor warning siren systems to provide additional warning of impending danger.  As their name implies, these sirens are intended to be heard outside. The system is not designed or engineered to be heard inside buildings, though you may be able to hear them in some structures, depending on how close you are to one of the sirens.

DO NOT CALL 9-1-1 OR ANY OTHER EMERGENCY TELEPHONE NUMBER UNLESS YOU HAVE EMERGENCY INFORMATION TO REPORT (for example, the sighting of a funnel cloud or other emergency).  If you are outside when the sirens sound, seek shelter immediately.  If there is not time to move to shelter, try to get into a low lying area, such as a ditch.  Lay face down and cover your head with your hands.  Be alert to rising water in ditches and low lying areas as the storm passes over.  DO NOT stand under trees if at all possible.  If a grove of trees is your only shelter, try to position yourself under the shorter trees.  This will provide you with the least likelihood of being struck by lightning.  However, a grove of trees should be your LAST choice for shelter.

Remain in shelter for thirty minutes after the sirens stop sounding.  If the sirens sound again during the thirty minutes, begin a new thirty minute period.  The sirens will not sound an "all clear", so remain in shelter for thirty minutes after the last siren sounds.

You can often be better prepared for severe weather by simply listening to the forecast before you leave home.  As we discussed elsewhere, every home should be equipped with a NOAA Weather Radio.  When they're not dispensing watch and warning information, these valuable tools will provide you with detailed forecast information.  In addition, you can often obtain the forecast from area radio and television stations.