Those strange clouds over Vancouver are called ‘asperitas,’ and they are very rare
A mesmerizing cloud formation, known as asperitas, graced the skies over Vancouver on Friday, captivating onlookers with its unique and striking appearance. The name “asperitas” is derived from Latin, meaning “roughness,” and was first documented in 2006 by an amateur cloudspotter in Iowa.
CBC’s science specialist, Darius Mahdavi, confirmed the formation, expressing his awe at the sight. He remarked, “I’ve only properly seen them once before…but these ones are even better.” Despite their ominous and stormy appearance, Mahdavi noted that asperitas clouds do not typically result in rainfall.
The formation of asperitas clouds remains somewhat of a mystery to meteorologists. However, they are often observed before or after storms in an atmosphere characterized by instability, updrafts, downdrafts, and significant changes in wind direction at higher altitudes. In 2017, these distinctive clouds were officially recognized and added to the World Meteorological Association’s International Cloud Atlas, described as an intense, chaotic wave-like formation.
Gavin Edmund Pretor-Pinney, the founder of the Cloud Appreciation Society, advocated for the recognition of asperitas clouds as a distinct cloud type around 15 years ago. He noticed a recurring pattern of these unusual clouds and believed they deserved special classification. Pretor-Pinney’s society connects cloud enthusiasts and shares information about various cloud formations.
Describing the appearance of asperitas clouds as akin to gazing at the turbulent surface of a choppy sea, Pretor-Pinney emphasized their rarity in Canada. While sightings are sporadic, with only one or two confirmed reports annually, they primarily occur over Ontario.
The ethereal beauty of asperitas clouds continues to fascinate and inspire awe in those fortunate enough to witness their fleeting presence in the sky. Whether observed in Vancouver, Ottawa, or beyond, these wave-like clouds serve as a reminder of the ever-changing and wondrous nature of our atmosphere.
