alarming
a-larm-ing
adjective
Causing worry, fear, or concern; disturbing or frightening.
"The alarming rise in crime rates worried everyone."
Thesaurus
Synonyms: redoubtable, dreadful, dire, unnerving, dreaded, hairy, chilling, gruesome, appalling, horrendous, forbidding, ominous
Antonyms: unalarming