When Edgar Allen Poe wrote “Once upon a midnight dreary”, in his seminal work, The Raven, there’s no doubt the clouds in his sky were nimbostratus formations.
Nimbostratus is the quintessential gloomy day cloud. Formless, encapsulating, and often concrete-gray, it’s hard not to feel a little run down when your blue skies are overrun with this particular cloud type.
They’re the reason your soccer game was canceled, why you had to hide your lovely outfit behind a frumpy waterproof coat, why your SAD goes haywire, and why your flight was delayed.
But they’re actually very interesting formations, so let’s fight our fears of the nimbostratus and stare straight into its pallid complexion for a moment.
Defining The Nimbostratus Cloud
The nimbostratus is a thick, blanket-forming cloud species with uniform gray coloring, more often than not delivering precipitation or even snow — not to be mistaken with storm clouds.
While they appear to linger at lower altitudes (which gives them a rather suffocating quality), sometimes, the upper body of the cloud will reach into the middle section of the troposphere, technically making them multi-level clouds.
This unseen girth is what gives them their moody, ash-gray hue, offering yet another link to the gothic, and the fact that it’s one of only two consistent producers of precipitation also adds to this cloud’s grim aesthetic.
The other purveyor of precipitation is known as cumulonimbus; however, this cloud type is more closely associated with sudden, dramatic downpours that leave as quickly as they came.
A steady, long rain, on the other hand, will almost certainly be falling from the nimbostratus.
Nimbostratus Cloud: The Facts
Here’s what you ought to know about the gloom king of the troposphere, the nimbostratus.
Étage (Cloud Level)- Nimbostratus are multi-level clouds that span the lower portion of the middle troposphere to the lower portion of the troposphere.
Altitude- Nimbostratus linger between 0.3 and 3.4 miles high (2000–18,000 ft).
Etymology- Nimbo is derived from the Latin for “rain”, while stratus is derived from the Latin for “layer”.
Abbreviation- Ns
Nimbostratus Color
Nimbostratus clouds are typically light to dark gray. As mentioned above, this is due to the thickness of their hidden upper bodies that block the passage of most light.
Potential For Precipitation
If you see nimbostratus cover, grab your galoshes, because you’re almost certainly going to need them. Precipitation will be light to moderate but will continue for hours, possibly all day and into the night.
Sky Coverage
If the nimbostratus is on the prowl, sky cover will be pretty cloudy to completely clouded over.
Nimbostratus Frequency
Being that it’s the bringer of drizzles, the frequency of nimbostratus depends on where you live, but in wetter climates, they’re incredibly common.
Nimbostratus Species
Nimbostratus is an only cloud child, by which I mean there is only one type and we’re talkin’ about it — it’s not a very nuanced cloud type in terms of form.
Nimbostratus Varieties
More of the same here, I’m afraid. There are no varieties to speak of. Nimbostratus is nimbostratus is nimbostratus is nimbostratus… you get the point.
Supplementary Features Of Nimbostratus
Some better news on this front. Nimbostratus clouds are commonly supplemented by two features, and here they are…
Nimbostratus Precipitation
Full-blown precipitation reaching the Earth’s surface.
Nimbostratus Virga
Strips of rain that evaporate before they reach a surface.
Nimbostratus Accessories
Nimbostratus may not be the most adventurous formation, but it does have one accessory, the nimbostratus pannus.
Nimbostratus Pannus
These are little ragged cloud scuds that will often appear near the base of nimbostratus clouds.
Comparable Cloud Types
There are three other cloud types that you may mistake for the nimbostratus.
Cumulonimbus
This is the cloud type I mentioned earlier on, the one that chucks it down as opposed to drizzle. Standing beneath one of each, it can be tricky telling them apart.
Besides the ferocity of precipitation, you can tell if you’re looking at a cumulonimbus cloud if you hear any thunder, see any lightning, or see any of the following cloud features:
Murus- Cloud wall
Arcus– Cloud shelf
Cauda– Cloud tail
Stratocumulus
Although nimbostratus and stratocumulus clouds look alike, there are two major differences. Firstly, the stratocumulus almost never brings any rain, and secondly, unlike nimbostratus, stratocumulus has many different species and varieties.
Stratus
Being that both nimbostratus and stratus clouds inhabit roughly the same altitude, are relatively formless and featureless, and can be thick and gray, it sometimes takes a keen eye to tell them apart.
Stratus clouds are often thinner, which is a giveaway, but when they’re thick, it’s the absence of rain that tells you that you’re not in the presence of nimbostratus clouds.
Final Thoughts
This has been your crash course in the pathetic fallacy of sadness and despair that is the nimbostratus cloud, a thick gray wadding that leaves your clothes and your soul feeling sodden.
But next time you’re caught beneath one of these woeful blankets, don’t hide under yours; get out there and see if you can spot any nimbostratus pannus! — don’t forget your raincoat, though.
Hi, my name is Andrew Capper and I have been a meteorologist for almost 30 years now. My line of work specializes in the scientific principles used to explain and understand the earth’s atmosphere and how that affects everyday life.
I created this website to share my knowledge and help others stay safe during extreme weather events.
I’ll be looking at weather forecasting, clouds, tornadoes, hurricanes, and much more - so, if you’ve ever been fascinated by the weather like I have been since I was a young boy, this is the site for you. Enjoy!
