Ottawa's Undulatus Asperitas Clouds

On Sunday evening, residents of Ottawa were treated to a mesmerizing sight as a sea of wavy, undulating clouds filled the sky just before a significant thunderstorm rolled in. These unique cloud formations are known as Undulatus asperitas, a name derived from the Latin term for 'roughness,' as explained by Geoff Coulson, a warning preparedness meteorologist with Environment and Climate Change Canada.

Coulson remarked, 'Anyone who witnessed the sky yesterday in the Ottawa area would understand why they use that term for that cloud. It does almost look like a rough sea, as seen from underneath, with distinct waves and bumps.'

A Rare Meteorological Phenomenon

Undulatus asperitas clouds represent a rare and relatively recent addition to meteorological terminology, having been officially recognized by the World Meteorological Organization (WMO) in 2015—the first new distinct cloud type in over fifty years. The Cloud Appreciation Society first proposed its classification in 2008, prompting extensive study by the WMO to confirm its uniqueness.

Characteristics of Undulatus Asperitas Clouds

These clouds are classified as stratocumulus, which typically exist at low to mid-level altitudes, ranging from three to four kilometers above the ground. Interestingly, while they are often associated with rainfall and thunderstorms, the WMO notes that asperitas clouds do not always signal wet weather. Their appearance often coincides with unstable atmospheric conditions, particularly before or after showers, which was the case in Ottawa this past Sunday.

Coulson explained that the stunning display was linked to a cold front pushing through the Ottawa Valley, creating a very unstable atmosphere. This instability results in intricate vertical air movements that contribute to the dramatic cloud formations: 'We had all the ingredients for a pretty dramatic sky.'

The Elusive Nature of Asperitas Clouds

However, these fantastic clouds are quite elusive and depend on several specific conditions to form. Looking ahead, meteorologists predict a much calmer weather pattern for the coming week, with only a few scattered showers expected. 'Rare appearances aren’t in the forecast for the rest of the week,' added Coulson.

Climate Change Considerations

When asked about any potential relationship between these clouds and climate change, Coulson clarified that their rarity does not necessarily indicate a connection to broader climatic shifts. 'Since meteorologists aren’t exactly sure why these clouds form, it’s challenging to determine if we’ll see more of them in the future,' he noted.

Storm Chaser's Experience

Storm chaser Connor Mockett, who traveled from eastern Ontario to capture this remarkable weather event, described the experience in vivid detail. He began tracking the storm early in the afternoon and followed it through various towns, ultimately witnessing the spectacular asperitas clouds near Carp Road, north of Kanata. Mockett, who has chased storms across Canada and the United States, declared it the most impressive display of asperitas he has ever seen, urging others in Ottawa to step outside and take in the view.

Conclusion

These beautiful yet bizarre clouds serve as a reminder of nature's intricate and often unpredictable phenomena. Keep your eyes on the skies, as you never know when another rare atmospheric display will occur!