According to meteorologists, the cloud isn’t really rare, we just don’t notice its appearance quite often. What looked like a long plank-shaped cloud was spotted in Birmingham, which caused the public to be curious about the odd object in the sky. The object is called an undular bore cloud, as Al details:
An undular bore is not especially rare, but getting such a good look at one is, according to Gary Goggins, a meteorologist at the National Weather Service in Birmingham.
“An undular bore is basically formed when you have rising air parcels on the front end of an old outflow boundary or gust front from thunderstorms. When the air parcels enter more stable air, that causes the air parcels to sink once again, causing the wave-like pattern at the front end of where the gust front used to be,” he said.
”It’s almost like a ripple in the water. Over time it goes out to where it’s almost like a wave on the outside part of a dissipating outflow boundary from old thunderstorms.”
This one formed from thunderstorms that rolled across north Alabama early this morning and dissipated just north of the Birmingham metro area between 6 and 7 a.m., Goggins said.
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