Answer: equinoctial

AnswerCrossword Clue
EQUINOCTIALSeasonal storm
equinoctialthe great circle of the celestial sphere, lying in the same plane as the earth's equator
equinoctialoccurring at or about the time of an equinox
equinoctialstorm of violent winds and rain occurring at or near the time of an equinox and popularly, but erroneously, believed to be physically associated with it
equinoctialrelating to the equinox / an equinoctial gale
equinoctialpertaining to an equinox or the equinoxes, or to the equality of day and night
equinoctialpertaining to the celestial equator