I took the photo below from my condo balcony.
Just below centre is a dark little Cumulus cloud. I know it’s a Cumulus because I’ve been doing a little research about clouds.
I also know that the dark swath of clouds angling in from the top left are Stratus.
Between and above them is a crumbly layer of Stratocumulus.
So what to make of all this?
I know that today was a turbulent day at cloud level.
There were huge Cumulus and threats of Cumulonimbus and thunderstorms all day. There were highly localized flood-making downpours of rain. The weather today was extremely humid and it’s forecast to remain so for a few days.
Those Stratocumulus and the high humidity suggest that tomorrow will also be an unsettled day. The Cirrostratus in the upper right also is telling me that the next 24 hours could be messy.
I checked my observations against the online weather forecast:
Close enough for this senior. I’ll think twice before planning a long walk on a park trail tomorrow or Friday.
This blog will explain some basics for understanding the clouds
Hopefully next time you’re looking out the window, or planning your next outing, you’ll have a better idea of what you’re looking at!
Clouds are classified as low-level, mid-level and high-level.
Here’s how they stack up. Many clouds look quite similar. So it helps your forecasting if you can figure out whether a cloud is low-, mid- or high-level.
One core concept to keep in mind is that as warm air with lots of moisture rises, it cools. And this rising cooler air cannot hold its moisture. As a result, we get rain.
Low-Level Clouds (base of cloud below 2 km/6500 ft):
These are classic cumulus clouds.
Cumulus clouds are low-level, “fair-weather clouds.” Their message is clear – you could safely predict that the rest of the day will be sunny/cloudy and bright.
Cumulus clouds such as these usually begin to pop up in the sky at about 11 a.m. and build through the day.
As a glider pilot, I saw them as a message to go flying. That’s because these cumulus clouds sit atop a parcel of rising warm air, the energy that would lift my glider up to cloud base – with no engine!
Keep a constant eye on a sky full of Cumulus clouds, because they’ll change as the day goes on.
If they’re being pushed upward like a chimney they may grow into a Cumulonimbus, and you could be in for a thunderstorm.
Pictured above is a classic Cumulonimbus cloud. It contains so much heat energy that it often can drive upward to 12 km (40,000 ft.) and even as much as 21 km (69,000 ft.) above the ground. That flattened, anvil shape signals the formation of a thundercloud.
There’s likely to be rain, lightning and even hail in a short while. It’s safest to pack up outdoor activities and seek cover (not under a tree),
Glider pilots call those long strips of Stratus clouds “Cloud Streets.” They act like a chain of upward-lifting thermals that could keep a glider in the air for a whole day and allow flight over long distances.
For walkers on the ground below, they provide much appreciated cover from the sun.
Stratus and Stratocumulus suggest that nothing exciting is about to happen today, weatherwise. But rain or thunderstorms are on the way tomorrow or the day after.
Mid-Level Clouds: (Base between 2 – 6 km/6,500 – 20,000 ft high):
Altocumulus clouds can take many forms. They can be long parallel bands, as above. They can be in local patches. They can be thick rolls that extend for kilometers and kilometers. They can be solid looking or semi-transparent.
If you’re trying to identify them, look for clouds that almost cover the sky, and look for their typical grayish-white color.
Altostratus are dull, gray and cover the sky from horizon to horizon.
They have some thicker spots, so the sky is not uniformly grey, as you can see in the image above.
Usually they indicate a warm front is coming – and the warm air will push moist air upward. The rising air will cool and release any moisture as rain. The rain is most often short-lived.
Nimbostratus is the worst-case development of Altostratus clouds – the fully opaque, often featureless cover of dull gray, accompanied by constant precipitation.
This is go-to-a-movie weather.
Unfortunately, Nimbostratus clouds and their rain or snow tend to hang around for a long time.
But at least knowing how to identify clouds, you can make an early call to move your day’s activities indoors.
High-Level Clouds: (base of cloud above 6 km/20,000 ft):
Thin, wispy Cirrus clouds are the highest of all clouds.
They’re made entirely of ice crystals, gently falling from the freezing cold limits of the atmosphere.
They indicate a change in weather on its way.
If the sky remains blue and the Cirrus spreads, the weather is likely to be fine for quite a while.
But if the Cirrus begins to descend, thicken and form other types of clouds, a warm front will arrive within a day or so.
Cirrocumulus clouds form when high-level Cirrus clouds are contacted by turbulent upward-moving air. Cirrocumulus live at great heights (near 40,000 ft.). They often look like Altocumulus, a mid-level cloud type. Here’s an easy way to distinguish one from the other:
Stretch out your arm to the sky. If you can cover a cloudlet with a single finger, it’s way up high and is a Cirrocumulus. If it takes two or three fingers to cover it, it’s much lower and is considered an Altocumulus.
Either way, both these clouds spell rain and storms for the immediate future.
Cirrostratus form out of Cirrus clouds on a sunny day.
While the weather can be very pleasant under Cirrostratus, the clouds signal a warm front coming in, which will force the colder air upwards.This means rainfall in about 12-24 hours.
A little knowledge about the clouds can help you, as a senior, plan your outings
Checking out the clouds can be a fun and interesting way to get a heads-up about what’s happening around you.
Stay dry out there, and keep looking up!