High River, Alta.’s passing clouds forecast produced strong sunbeams leading into the evening. Partly sunny skies were at a 20 C high over the weekend.
Ice crystals in the sky known as cirrus are the fibrous strands of cloud formations seen in the atmosphere. Shape, height and moisture specifications are used to identify different types of clouds.
According to Environment Canada meteorologist Kyle Fougere, cumulus clouds are one of the most common types of clouds observed, given the number of sunny days seen in Calgary.
“It’s also very common for Calgary to have high cirrus clouds,” he said. “These often blow into Alberta at high altitudes from low-pressure systems in British Columbia.”
The formations from June 10 to 27 were forecasted as cloudy days. Describing the photos, Fougere identified the formations as either cumulus or stratocumulus clouds.
“Cumulus clouds are very common from the spring into the fall in Alberta,” he said. “They form when the sun’s rays heat up the surface of the Earth. Air parcels near the surface warm and rise, cooling as they move higher in the atmosphere. When the air cools down to its dew point, the air becomes saturated and the moisture in the air condenses to form clouds.”
Fougere focuses on meteorological activity. According to the Government of Canada’s website, “meteorologists develop forecasts and warnings using computer models and real-time weather data such as radar imagery.”
Environment Canada’s skywatcher’s guide ranges the classifications within low, medium or high charts. These charts are useful for looking at cloud types such as a stratocumulus.
Environment Canada’s website says, “the cloud elements in stratocumulus appear larger because they’re closer to the ground than altocumulus.”
At the outskirts of the city limits, there were cooler temperatures than the day before. Dark bases of the clouds signal precipitation about to occur. Stratocumulus clouds, such as in the photograph, are a layer of cumulus clouds and are being pushed from northwest winds.
Passing clouds over Nose Hill Park on June 15 moved southward from gentle winds at 15 km/h. Cumulus clouds are regular patterns seen from spring to fall.
Marlborough Mall in the city’s northeast experienced sprinkles of precipitation around 3:00 pm. The scattered clouds were part of a partly sunny forecast, with winds coming in at 19 km/h. According to Environment and Climate Change Canada, they can be identified by their shape, height and rain they produce. Moisture in the air is the condensation process where clouds come from.
A hot evening climate over the west end of downtown (Contemporary Calgary), from 6th Avenue, covers the Sun. Low, medium and high level coverages classify different types in the atmosphere. According to the International Cloud Atlas, “When this layer (vertical direction of the cumulus) is very stable, convection ceases and the whole cloud mass spreads out.”
Cumulus clouds, identifiable by the flat bottoms usually wider than they are tall, float across southbound Macleod Trail S.W. The cumulus clouds, when gathered together, form stratocumulus.
The puffy clouds can also grow taller, becoming towering cumulus or cumulonimbus (rain showers). Thunderstorms develop out of these weather types when the air reaches “instability,” meaning cold air is circulating around the cloud and collecting high amounts of moisture.
The World Meteorological Organization (WMO) defines sky conditions that can happen day or night.
Sky conditions the WMO specifies are away from mountains and sea. The definitions also include that the air is clear, and the sun is high.
“It will be necessary to adapt the definitions to other conditions,” the WMO says. “In many cases, this can easily be done; for example, by night when the Moon is in its brighter phases, it may play, with regard to the illumination of clouds, a role analogous to that of the Sun.”
All photos: Floyd Black Horse