Predicting the Weather With Clouds

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Introduction: Predicting the Weather With Clouds

About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

Being able to predict the weather by observing cloud formations is a skill that is somewhat lost on us modern humans. Most of us can easily look at a cloud and see the unicorn or ice cream cones, but very few of us can look at clouds and see the approaching cold front.

Fortunately, being able to predict the weather is easier than one may think. Follows is some helpful information to get you started. It will no doubt wow, impress and keep you dry on your next family outting into the great outdoors.

Step 1: Categorization

Clouds can easily be broken into four categories. These categories are high clouds, middle clouds, low clouds and clouds with vertical growth.

Clouds are also identified by shape. Cumulus refers to a "heap" of clouds. Stratus refers to clouds that are long and streaky. And nimbus refers to the shape of "rain" because we all know what rain looks like.

Step 2: High Clouds

High clouds form at 16,000 - 43,000 feet. Basically, these are the clouds that you only encounter on the top of really high mountains or at the cruising altitude of a jet airplane. Due to the extreme conditions at which they form, they tend to be comprised primarily of ice crystals.

High clouds do not block sunlight.

High clouds include:
Cirrus
Cirrostratus
Cirrocumulus

Step 3: Cirrus

Cirrus clouds are white wispy clouds that stretch across the sky. By all accounts, cirrus clouds indicate fair weather in the immediate future. However, they can also be an indication of a change in weather patterns within the next 24 hours (most likely a change of pressure fronts).

By watching their movement and the direction in which the streaks are pointed, you can get a sense of which direction the weather front is moving.

Step 4: Cirrostratus

Cirrostratus tend to be sheet-like and cover the whole sky. You can usually tend to see the sun or moon through them. Their pressence usually indicates moist weather within the next 12 - 24 hours.

Step 5: Cirrocumulus

Cirrocumulus clouds tend to be large groupings of white streaks that are sometimes seemingly neatly aligned. In most climates these mean fair weather for the near future.

However, in the tropics, these clouds may indicate an approaching tropical storm or hurricane (depending on the season).

Step 6: Middle Clouds

Middle clouds form at 6,500 to 23,000 feet. They are comprised of water, and, if cold enough, ice.

Middle clouds often block sunlight, but not always.

Middle clouds consist of:
Altostratus
Altocumulus

Step 7: Altostratus

Altostratus are grey and/or blue clouds that cover the whole sky. They tend to indicate a storm some time in the very near future since they usually precede inclimate weather.

Step 8: Altocumulus

Altocumulus are grayish-white clouds blanketing the entire sky. The tend to look like large fluffy sheets in which there is a lot of contrast between light and dark. Sun does not pass through them. If you see them in the morning, prepare for a thunderstorm in the afternoon.

Step 9: Low Clouds

Low clouds form below 6,500 feet. These clouds are the ones that like to hang-around just above tall buildings. These clouds tend to contain water, but can also be comprised of snow if the weather gets cold enough.

Low clouds block sunlight and can bring precipitation and wind.

Low clouds include:
Stratus
Stratocumulus
Nimbostratus

Step 10: Stratus

Stratus are low-lying solid clouds that are often formed when fog lifts off the ground. They obviously look like an elevated fog. Often they bring drizzle or light snow.

Step 11: Stratocumulus

Stratocumulus are low-lying bumpy and grey clouds. They do not bring precipitation. They also do not cover the entire sky and tend to come in rows and patches.

Step 12: Nimbostratus

Nimbostratus is your standard rain cloud. It is a large flat sheet of grey cloud with a little bit of differentiation. If you see these, chances are it's raining outside.

Step 13: Clouds With Vertical Mobility

And last, but not least, are clouds with vertical growth which tend to have a base that hangs really low (5,000 feet) and a top that climbs really high (over 50,000 feet).

Clouds in this category include:
Cumulus
Cumulonimbus

Step 14: Cumulus

Cumulus clouds are your stereotypical white "cottonball" clouds. So long as the clouds remain low clumps floating across the sky, there will be fair weather. However, you need to keep an eye on these clouds because any vertical growth can indicate the start of a large storm.

Step 15: Cumulonimbus

Cumulonimbus are cumulus clowds that have grown vertically into an anvil-like shape. The anvil tends to point in the direction the storm is moving. These clouds bring most dangerous weather such as rain, lightning, hail and tornadoes.

Step 16: That's a Lot of Information. Now What?

Alright, now that we know what the basic types of clouds are, we need to look up at the sky.

Go outside and look at the sky. If there are no clouds in the the sky, then the weather is fine.

Assuming there are clouds in the sky, we now need to identify them.

First, determine if you can see the sun or moon through them. If you can, then you are looking at high altitude clouds. If the clouds are thick, then there is a chance of poor weather a day or two in the future. To determine when the storm will arrive, observe whether or not the clouds appear to be moving. If they appear stationary, it is a slow moving front and probably won't arrive for over a day. If they appear to be moving, then the change in weather will be there faster. You can tell which way the storm is traveling by the direction the clouds are pointing.

If you can not see through the clouds, chances are that you are looking at middle or low altitude clouds. First, determine which of the two you are dealing with by observing shape, color and other more obvious give-aways. Are they covering the entire sky? Then they may be middle altitude clouds. Do they appear to be grey with a blue tint or fluffy white/grey clouds with a lot of contrast between light and dark? If yes, then these are middle altitude clouds and you should prepare for rain within half a day.

If you answered no to any of those questions, then check for low-altitude clouds. These tend to appear low and often engulf mountains and buildings. If it looks like an elevated fog, expect drizzle (if it isn't already). If it is rows of low, dark, lumpy clouds, then the weather is otherwise okay, but watch for further developments. If there is a low, dark, grey sheet, then it's probably raining. If it's not, quickly go get your umbrella.

If your clouds are low, fluffy, and white like cottonballs in the sky, then the weather is okay. However, keep an eye on these for any vertical growth of the cloud upwards into the sky (turning into anvil shapes). These clouds can unexpectedly change from fair weather indicators into violent thunderstorms.

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    95 Discussions

    What if I see multiple types of clouds at once?

    Thanks for this :-) I knew a little about clouds from a forest ranger but that was great-I'm hoping for a storm here in the UK as it's so humid and have been watching the clouds but now I am even more savy!! Thank you :-)

    verry helpfull !

    If you know the roots of the cloud names (e.g. nimbus=rain, cumulo=to heap), they're easier to remember.

    Fun article!

    thank you ... I've been looking for something like this!

    love it!!!!!!!!!!!! it helped with my science project

    Hi
    I'm very curious realm of clouds and weather forecasting. I wanted to ask a few things I dont understand :1) when predicting cloudiness,you predict acording to contracts by regions over the mountains or sea etc., or by the amount of space itself? I would be happy even if in addition to your answer,you will have related articles to prove this. 2) I read that there are types of clouds, not that I figured it out, but I wanted to know if the type of cloud is considered when forecasting the cloudiness of a particular location?

    thanks shir :)

    Excellent article, I've used it as a derivative to instruct cadets on predicting weather patterns in the field, in order to assist them with preparation for personal equipment to take on field training.

    Quite resourceful and interesting. Great job dude keep up the good work.

    Hey, I just want to say this information has helped me a lot. I am a Wando Band Student, and during our marching band season, it is important to keep an eye on the weather. I just wanted to ask a question though,

    What if you see Alto Cumulus clouds in the mid-morning (around 10 or 11 AM ish)? Does it still mean a chance for rain in the afternoon? Are they actually Alto-Cumulus time? Please explain.

    Thanks sooooo much for your time. I really appreciate it! :)

    Thanks for the information! I'm doing a science fair project on Meterology and this is a really big help!

    put together very well, simple and understandable, Thank You. In regards to WIND that is a whole new ball game...there is a morning wind (east to west, generally cooler as the mtns draw from the low lands) From approx 2-3pm there is "dead air" (the hottest part of the day) From 3pm into late evening is the warmer winds (west to east), most times bringing wet weather.

    Stratocumulus also tend to mean a storm will probably happen somehwere near(ish) that day. If you see them meeting with another cloud formation, such as nimbostratus. If you see nimbostratus clouds stop in a vey distinct line, and stratocumulus meeting, crossing, or coming near that line, plan for an indoor day with the possibility of severe weather directly to your north, south, or above you that day. In some cases, you will be able to watch a potentially severe stack go up over or just to the east of you, in which case someone about 100-250 miles to the east of you is about to have a bad day. At least that's what happens here, on the very western edge of tornado country. Many days, I can look up at the sky and predict (not well enough to become a pro stormchaser, unfortunately) whether severe weather will happen, and predict where it will be, such as "That sucker's going to do something nasty (tornado or bad hail) over at about I-76 and the state line." Or "From the looks of that, Peyton/Calhan is in danger today. We oughta call Sue and Bud, make sure they're alright in about four hours." For a while I could get people to bet me on that, then we'd sit around watching the weather radar and let the money change hands.

    4 replies

    Actually the pros don't observe clouds in making their morning decision as to where they will go that day. They can't because there destination may be a State away, when they start the chase. Of course they use cloud observations to fine tune the chase if their morning prediction was accurate. Sometimes they are good or lucky, perhaps both. I recall a Sunday when Chasers from Oklahoma where in NW Kansas waiting when a tornado formed. The NWS even hadn't even issued a tornado watch for that day. :)

    Yeah, I wish cloud-watching alone would make it possible to tell where a tornado might be, in time to get near there. If it was possible to predict clouds well enough by eye to go pro, I'd want to develop that skill. But as it is, I have to wait for a cell to start, and then do the judgment call: go for the north one, or the south one? Any cloud-watcher does, but if I wanted to see a twister, I'd be in the wrong spot to get near it in time. I like it that way. It's just that all the severe weather rolls off of the front range, so if something is going to hit the west 1/4 of Kanses/Nebraska, or any part of CO, I get to watch it form before it goes off somewhere past the horizon to forcibly remodel someone's home.

    However I must add to my previous reply that your remarks confirm what I want to say :
    1) your "expertise" in forecasting is local and is based on multiple factors starting with a good knowledge of local factors that was built over the years ;
    2) TV weather forecast and other pro weathermen are on th whole very reliable, albeit some rare mistakes of course.

    Actually your remark are very useful as you give practical examples to what I say on a more general level.

    Thank you & Happy New Year to you an all your relatives (I know this is important in your country).

    @ static and rishnal :
    I didn't feel that Randolfo wants to use his cloud reading for tornado forecast…
    I think he writes on a more general level.
    As for myself, although I feel I have a proper overall notion of weather forecasting, as I live in a land were tornadoes do not exist (God forbids !…) in no way would I allow myself to forecast a tornado in one of your states.
    This would be totally preposterous and ridiculous !!!…