St. Elmo's Fire

St. Elmo's fire (also St. Elmo's light) is a weather phenomenon in which luminous plasma is created by a coronal discharge from a sharp or pointed object in a strong electric field in the atmosphere (such as those generated by thunderstorms or created by a volcanic eruption).

St. Elmo's fire is named after St. Erasmus of Formiae (also called St. Elmo, the Italian name for St. Erasmus), the patron saint of sailors. The phenomenon sometimes appeared on ships at sea during thunderstorms and was regarded by sailors with religious awe for its glowing ball of light, accounting for the name. Because it is a sign of electricity in the air and interferes with compass readings, some sailors may have regarded it as an omen of bad luck and stormy weather. Other references indicate that sailors may have actually considered St. Elmo's fire as a positive omen (as in, a sign of the presence of their guardian saint).