hey, my 2010 had alarm issues out of no where a few times!!!
mine are similar but i was able to start the car and drive it while the alarm and horns and such were going off...
one thing i had to do immediately was take out the fuse for the horn!!! at least that way you can trouble shoot or check around with out waking up the entire neighborhood while you check around.
my case- after i disabled the horn fuse... i just let it flash and blink until it stopped on its own. then it hasnr happened again.... KNOCK ON WOOD, though-
EDIT----- below is a link to my old ranting of the alarm in the past- maybe theres info in there that might help, who knows. gl-
Alarm system issues...pita!!!