The science behind clouds and how to remember their (latin) names

Puffy, wispy, white and gray, we’ve seen them all this spring. Clouds come in a variety of types, and each type comes with critical information about incoming weather patterns. If you’re a local hiker, boater, pilot or otherwise outdoor-enjoyer, you can understand the value of eyeing a storm before it arrives.

As we head into summer, we’ll see a little less of thick gray clouds and a little more of those “Toy Story” wallpaper clouds – otherwise known as cumulus clouds.

Cumulus, cu-mongous, stratus something or other, what’s it all about? Latin, actually. Luckily it does make a lot of sense once you break it down.

Clouds are named by type, altitude and general behavior and appearance. Start at the beginning with a prefix. If it starts with cirro-, that means high. If it starts with alto- that means middle. No prefix? That’s low altitude.

The root words in the name describe the cloud. Cumulus in Latin means a heap, a pile, an accumulation. As in an accumulation of laundry. These are clouds that have that tall, castle-like appearance.

Stratus means to flatten out, to cover with a layer, to spread. Like stratified layers of sedimentary rock. We’re talking sky lasagna, here.

Now when you start combining things into long, hard-to-pronounce words, what was once cloudy should now be a little more clear.

Cirrostratus, altostratus, stratus. High lasagna, middle lasagna, low lasagna. Cirrocumulus, altocumulus, cumulus. High laundry, middle laundry, low laundry.

One thing to note with this laundry visual. The higher the altitude, the more scattered the “heaps.” Cirrocumulus can appear as fine dots or ripples in the sky from our perspective. To stretch this analogy further, I suppose you could imagine it’s because the higher-altitude laundry has been sitting there longer and sky people have rummaged through it several times to find their favorite top. Don’t question it; it’s called a mnemonic device.

In general, those wispy clouds way up in the sky are cirrus clouds. In Latin it means a lock of hair, a bird’s tuft or a tuft of horsehair. They tend to be pretty curly, and they are always icy. Curly ice. Cirrus.

Last but not least in the general cloud type breakdown are the rainmakers, nimbo and nimbus. Nimbo if it’s a prefix, as in nimbostratus, and nimbus if it’s a suffix, as in cumulonimbus. Break it all down and you have either raining lasagna or raining laundry.

Nimbus can be used as another word for halo, which hearkens to the godlike appearance of these clouds. As in, you may be reporting an act of god on your insurance claim later.

And by general breakdown (or genera if you want to be fancy and Latin about it), meteorologists mean general. Because it gets deeper. There are cloud species, there are cloud varieties, accessory clouds and special clouds. It goes on. Fibratus for fibrous-looking clouds, lenticularis for lens-shaped clouds, undulatus for wavy clouds.

The meteorologists know the really cool and obscure ones.

“I really enjoy hole-punch clouds, also known as fallstreak holes,” KHQ weather forecaster Justin Spinnie said. “They appear when planes fly through upper-level clouds that contain supercooled water droplets, meaning the water droplets are below freezing temperatures but still in liquid form. When planes fly through them, it triggers the freezing process and they become ice crystals. Those ice crystals then evaporate leaving behind a hole that moves with the cloud.

“They almost look a bit cartoonish when you see them in person.”

But on to the functional information – what do these cloud types mean for my picnic plans?

The rainy ones, nimbus, you know already. The clouds that tend to predict changing weather, typically before the nimbus clouds roll through, are the high-altitude ones. This is because high-altitude clouds tend to be the ones on the leading edge of an incoming front. A front is where two air masses with differing temperatures and moisture levels meet. Spoiler: Those differences don’t mix well and that’s when we get what we colloquially refer to as “weather.”

Cirrocumulus is especially known to be foreboding, traditionally referred to as a “mackerel sky” because of its resemblance to the pattern of a fish’s scales. It can often forecast potential hurricane weather in tropical regions.

Your average cumulus clouds hanging out in the middle of the sky are usually associated with fair weather. The taller the cumulus, the more moisture there is in the atmosphere and the more likely there is to be precipitation. Cumulus clouds tend to bring showers and short bursts of rain.

Stratus clouds tend to mean stable weather. The air is moving with little vertical motion, which is what creates the even layers of stratus clouds. Stratus clouds can mean rain, but it’s usually drizzly and longer in duration.

Now you know enough to step outside and start honing your cloud classification and forecasting. Your friends probably won’t care at first when you point to the sky and exclaim, “Cumulonimbus!” but they might just thank you later.