[1] In early spring, the jet stream starts to move northwards, allowing large depressions to bring strong winds and rain in from the Atlantic.
In one day the weather can change from springtime sunshine to winter sleet and snow.
The track of these depressions can often be across Ireland and Scotland bringing bands of rain followed by heavy showers (often of hail or snow) and strong blustery winds.
In France, this meteorological phenomenon is known as "Giboulées de mars" (March sudden sleet showers).
The phrase is referenced in the General Prologue of The Canterbury Tales: "Whan that Aprill, with his shoures soote The droghte of March hath perced to the roote".