The Element Encyclopedia of Witchcraft: The Complete A-Z for the Entire Magical World - Judika Illes 2005
Caillagh Ny Gueshag/ Caillagh Ny Groamach
Caillagh is the Manx variation of the Gaelic word Cailleach (see next section). Exactly where she originated is unclear but according to legend, Caillagh Ny Gueshag, the “Old Woman of Spells,” was thrown into the Irish Sea for practicing witchcraft. On Imbolc, she was cast ashore on Manx shores and found herself transformed into Caillagh Ny Groamach, the “Old Women of Gloom.”
She is a weather spirit. When she first landed on the Isle of Man, she gathered sticks to build a fire to dry and warm herself. It turned out to be a very wet spring: she didn’t have enough sticks to stay warm for the whole season. (Apparently Caillagh Ny Groamach can only gather sticks on Imbolc.)
Since then, every year she attempts to gather enough sticks for the spring season. In a precursor to Hedgehog Day or Groundhog Day, Caillagh Ny Groamach’s success determines the rest of the season’s weather:
If Imbolc is fair, she’ll gather enough sticks and so won’t care if it rains all spring.
If Imbolc is wet, she can’t go out gathering and thus must ensure a dry season.
See CALENDAR: Imbolc.