Equinoctial storm

From Glossary of Meteorology
(Redirected from Equinoctial storms)

equinoctial storm

(Also called line storm, line gale.) Severe storms in the United Kingdom and North America that are popularly believed to accompany the vernal and autumnal equinoxes.

The belief may have originated in the mid-1700s when sailors observed the West Indian hurricanes, which are most frequent at about the autumnal equinox. Statistics of gale frequency do not show that storms are especially frequent in temperate latitudes about 22 September, though it does sometimes happen that the first severe storm of the winter half-year occurs toward the end of September. The belief has been extended by analogy to the vernal equinox, about 21 March.

Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.