I will preface this blog with a little story. After Rise & Shine Tuesday morning, my chief engineer got to work and said it looked like it was snowing outside. The odd part here is that my morning camera operator said the exact same thing. Still I didn’t believe either of them and insisted that it just had to be the freezing fog and frost sitting on the grass. After all, it was 20 degrees. Deciding to humor myself I chose to take the way home that both of them take to work, and to say my mind was blown is nothing short of an understatement. Low and behold on the roads was what appeared to be some snow or ice. I got to my apartment and was utterly perplexed. Got in and decided it was time for some research.
I came to what I thought was the only conclusion possible. I decided that it was snowing, but the snow wasn’t falling out of the clouds and to the ground because the clouds were already at the surface. That seemed to make sense to me, and I was proud of myself. Still I snapped a picture, sent it off to a mentor of mine, and asked his thoughts. Turns out, I wasn’t exactly wrong.
Let’s discuss the setup we had yesterday, and go in-depth a bit. We were far from in short supply of fog yesterday with a visibility of less than a mile it was obvious. What is fog? Fog is just surface cloud cover. What are clouds? Clouds are just billions of super-cooled water drops. What is super-cooled water? This one is actually pretty cool. Super-cooled water is nothing more than liquid water that is in an environment where the temperature is below freezing. This is where it gets interesting. This is also, where my mentor helped quite a bit, and I think him for it. A key to yesterday morning was remembering that the temperature was only about 20 degrees and even cooler in spots. This allowed the super-cooled water to begin to crystallize. This now makes the liquid water a solid. Those ice crystals now have the ability to stick together and become heavier as they do so. As those crystals become heavy, they are overcome by gravity and fall out of the cloud.
The phrase “falling out of the cloud” is somewhat incorrect. The clouds were already at the surface so there was really nowhere for the ice crystals to fall. This means the crystals had no opportunity to go through the rhyming process and collect super-cooled water as they fell through the clo0uds. This means that whatever hit the ground or the trees was incredibly dry ice. Don’t be confused here with the dry ice we’re all familiar with. Here I’m talking about ice crystals that have no water on them. That’s why when you touched the “snow” it was very fine and looked like something that resembled sugar or very fine white sand.
All of that being said, it still created some slick spots, but also made for some fantastic pictures. Happy Wednesday and that wraps up this edition of Meteorology 101.