Altocumulus Sunset Over Prospect Park’s Long Meadow Last Night
The weather is rainy and cool today in New York City. If you were out walking last night, you might have seen the warning signs of the changes to come. Cirrus, cirrostratus, and cirrocumulus clouds traveled across the sky in a gorgeous display, colored pink and purple by the setting sun.
When you see these three types of high-altitude clouds together, it means that there’s instability in the atmosphere. Unlike nimbus clouds, which are mostly made of water, the cirrus clouds are full of ice crystals. The cool temperatures become volatile when they mix with the warmer rising temperatures, sometimes causing larger storm clouds to form.
The appearance of cirrocumulus clouds, as seen in the photo below, indicates fair weather, but only for the time being. Last night, the weather was pleasant as the sun set around 8:30 pm. There was a slightly cool breeze in Prospect Park, and the temperature was at a comfortable level, just below 80 degrees Fahrenheit.
Sometimes referred to as a “mackerel sky,” the clouds in a cirrocumulus formation are actually a series of cloudlets. Each patch of ice is regarded as a separate cirrocumulus cloud. If these scattered clouds descend lower in the sky, they can become altocumulus. These middle altitude clouds usually indicate a cold front moving in.
At the north end of the Long Meadow in Prospect Park, cirrostratus clouds covered a large portion of the visible sky. The formation of these thin frozen clouds is more uniform than the cirrocumulus. If the sun had been higher on the horizon, we would have likely seen a halo forming around it.
In the photo below, you can see the cirrostratus clouds separating out into cirrocumulus clusters at the top of the cloud formation. Temperatures reached 82 degrees Fahrenheit yesterday. Today? We’re looking at a low of 49 degrees. Chance of rain: 100%.
The cirrus clouds hanging over Prospect Park took on the brightest hues, in shades of brilliant pink and purple. Thought to resemble horse’s tails, the wispy clouds are the most common warning sign of changing weather. Some altostratus and stratus clouds could be seen when facing the south end of the Long Meadow. These shapeless, low-hanging clouds don't carry enough water to threaten a serious thunderstorm. However, the presence of the multiple cirrus clouds - especially the cirrocumulus developing into altocumulus - is a sure warning for wet weather ahead.
Did you see the sunset last night in New York City? What did the sky look like from your vantage point? The weather forecast currently shows rain all weekend, but maybe we’ll get a sunny Memorial Day on Monday.