Lecture 6: Introduction to convective storms and precipitation formation
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- เผยแพร่เมื่อ 9 มิ.ย. 2024
- UPDATE: I'm making materials available for all of my lectures on my website (melstrong.org) for either those bored folks stuck at home due to the virus or teachers looking for online content.
In this lecture I go over the formation of convective storms. We talk about precipitation formation, lightning, thunder, hail, tornadoes, and unstable air.
This was originally part of the Blue Planet lecture series at the University of New Mexico. If you are interested in weather, this lecture is now part of my "weather short course" playlist, where there are another ~15 videos similar to this one.
I can't get over how you've made this content so easily understandable. Watching this entire series from the beginning gives you a much better understanding of weather. You're an incredibly gifted teacher, thank you for the time you took to make all of these!
Thank you very much! I'm glad to hear someone is using them. I appreciate your comments!
Absolutely, these videos are 100% halal and this nigga 100% real 💪
I'm about to graduate with my bachelors in meteorology and your videos have reallyyyyy helped tie everything together and clarify everything that wasn't perfectly clear. you explain everything so well and make it so easy to understand. truly the definition of a great teacher!!!! i cant thank you enough for making these accessible.
As a weather enthusiast, I'm really enjoying your lectures as a means for understanding the processes that make weather happen. Thank you for uploading these!
Thanks - someday I will make more....
I could not overstate how good your lectures are. Thank you!
I’m studying to become a glider pilot, and if I want to get my license I have to go trough some exams, including meteorology. Your videos helped me so much that words can’t even describe. Thank you very much for your time and all the great informations that you have given us❤️❤️
Mate, thank you. This is the most intuitive talk on the subject I've ever heard. Your visual representation of the information are brilliant. They tie it all together. I'm very grateful.
Your lectures have been some of the most clear and easy to understand that I have found. I appreciate you making and sharing these.
Thanks for that - I hope you get something out of them.
Amazing pedagogical skills. I've been watching meteorology lectures for a couple of months and yours are by far the best in terms of explanations and clarity. I'm so happy I found them. Thank you very much.
Hey thanks!
This series is filling in so many gaps in my understanding. Thank you! Suspect I will watch 2-3x to really get it!
Oh man Mel. This lesson was delivered 5 years ago, 2018 to be exact and today as I write this is 15 November 2023. As I was watching this lecture on the microbust outflow, immediately my mind went back about 2 months ago, here in Pretoria, South Africa. I remember it vividly, the sun had just gone down, there were no clouds in sight, there was no wind at all then all of a sudden all hell broke loose. A strong wind carrying lots of dust swept our area for about 1 hour 15 minutes and you are so right Mel, we would later learn that there was a bad weather in a neighbouring province. I didn't know all this until I found your channel and having to accidentally learn about something that I personally went through it. It is amazing how education can do to a person. I now feel like I was a prisoner of ignorance. Education is a freedom. What a teacher! You are simply the best Mel.
As a pilot I really enjoy your videos, thanks for your stuff!
Thanks glad to hear it!
Thank you to you and your cats for these excellent lectures!
I'm safely assuming you're a professor. What a perfect fit! Seriously, this is impressive teaching. Great explanations.
Hello and thank you for the nice comment - I haven't produced any new videos for several months but I will have more coming eventually.
I've been looking for something like this for years!! It's such a blessing that I found your channel. I wish I could give you more support than just a sub, like and comment.
I’venom watched several of your lectures. You are a gifted educator. Thank you.
Love that you love your cat so much and a great lecture thank you.
03:56UTC..Hi Mel..I am a weather observer in Papua New Guinea. I find your lectures very educational.
Seriously! whoever interested in Geography in particular meteorology must watch your videos, i strongly recommend it. Showing us the example clips while explaining the concept will help in getting hold of the subject.. This is how i prefer learning. - Thank you
Great series of informative lectures. And with the Bond villain look stroking the cat :-)
I found your lectures yesterday and I’m hooked! Just watching this sixth one now. They are just fascinating and do educational. Some of the clips shown, eg. Microbursts, are amazing. Great job, Mel.
Thanks for your comment - hope you're learning something!
Fascinating lecture, thanks!
As to the 5mm or so limit on raindrop diameter, I have personally witnessed raindrops as large as 24mm. Under rainclouds dropping large amounts of rain through very still air. The falling rain induces a downdraft in the air. This downdraft reduces air resistance on the falling rain drops, allowing them to grow or remain very large.
One of the most incredible ones I’ve witnesses came during a late afternoon downpour on the north side of Michigan’s Upper-Peninsula. An airmass that had drifted off lake Superior just dumped rain down as if a huge bucket had been overturned up high. The air was as still as an early morning. The rain drops got as big as US quarters, 24mm. It was an incredible sight.
Then there was nickel-sized (19mm) raindrops falling west of a massive orographically induced storm caused by humid air being lifted over the west side of the Tetons. A ton of rain, huge raindrops, and ferocious lightning all around and not a speck of wind. Eerie and incredible.
The best weather videos that Ive come across! Thanks for sharing this.
I started my day just questioning 'what actually is a Cloud?' (-microsoft -computing) and found myself watching Pecos Hank videos and now yours. Pecos refined my questions, you answered them. I have others now of course which means I'll be looking for your other lectures to fill that gap of knowledge. Who would know how fascinating cloud knowledge could be.
It did not go unnoticed that three different cats appeared in this video. You snuck them in. Very sneaky of you to make me laugh
Thanks for your comment. Cats come and go as they please...
Excellent. Covering the microbursts is very important for pilots. This is a great series and we thank you for your very generous donation of time and effort to educating an ignorant mass.
I'm studying climate science in France and your lectures have been really helpful. Plus, I miss my cat who is back home at my parents' : seeing your lectures with a cat is the best combo !
This is the video I've been needing, thank you and great job!!!
Thanks - glad you found it useful.
Excellent video, have learnt something
I'm very interested in how super cells function as well as Tornado formation, so I came here solely for this lecture; however, after getting half way through the video, I realised I HAD to know more, and proceeded to watch the whole series up to this point. I now have over 40 pages of notes and cannot believe how much context and wonderfully presented information you are able to dispense in such a short period of time. The only problem is I'm studying English Literature, and now I think I made the wrong decision!! Cannot wait to watch the rest of the lecture series, I really wish you were my professor!
Wow thanks Ryan - these are the comments that teachers/professors wish they received but we never do! And after you watched all those videos - nothing about supercells, which I didn't really go over. So here is a super brief explanation. When I am talking about thunderstorm formation and evolution in this video, I draw a picture of the processes happening inside a single thunderstorm cell, with updrafts and downdrafts next to each over. Over time, the downdraft becomes larger and eventually blocks the updraft. The lack of new incoming moisture shuts the thunderstorm off - from start to finish only takes about 20 minutes or so.
The general idea behind a supercell is that the updraft does not get blocked by the downdraft. In order for this to happen, there needs to be a wind aloft that is moving faster than wind at the surface - we call this "wind shear" when it happens. This can cause the rising thunderstorm to tilt as the upper winds are essentially causing it to lean over. One consequence of this is that the updraft is prevented from being blocked by the growing downdraft. The wind shear essentially keeps them separate. This allows the thunderstorm to keep growing into a supercell. So to get a supercell, you not only need unstable air and high dew point, but you also need wind shear.
@@MelStrong Thank you very much Mel. Your time is appreciated greatly. I'm on Lecture 9 now and looking forward to learning about midlatitude cyclones and fronts! My notebook is officially full! Thankfully I have a spare! Also, wrong video, but Lecture 8 where you described the dust particles from N.Africa fertilizing the Amazonian soil blew my mind! Especially given I'm now addicted to Earth.nullschool, so can actually watch it live. As always, great content. I'll see you in the comments somewhere down the lecture series! Thanks again.
This videos should be mandatory in any glider pilot course.
Learnt many fascinating things from this lecture!!! Awesome 👍
I love these videos! So fascinating.
oh man this is so damn good. The whole series is.
Thank you for the amazing lectures
Pecos Hank has some really great storm chasing videos--was jazzed that you mentioned him!
Yeah that guy is really dedicated. Amazing photography. So good that I don't even try.
I really enjoyed watching this. Incredibly interesting and easy to understand. Thank you
Thanks for your comment!
Great lecture. Much appreciated.
I'm actually learning something! You have excellent pedagogical skills!
Thank you!
Thank you for actually learning something! :)
Outstanding work!
Thank you very much for another fantastic lesson! 🙌😊
You are incredible. Thank you so much. ❤
Super enlightening lecture, thanks!!!
Very easy to listen to and follow allong. Thank you very much!
Thanks for watching and hope you learned something!
Enjoying that updrafts flow upward and downdrafts flow downward, so that I can focus on remembering that deep convection goes high up.
This was great!! Very informative and useful information for us in tornado alley. I feel like I’m back in college watching these, will definitely be watching more!
Hey thanks - I had to skip over a lot of tornado stuff because there was a lot of other stuff to cover.
Mel Strong I thought it was perfect. Good info on the conditions that develop into tornadoes.
Thank you for your lectures. they really inform me about things i never would have known
Thanks!
This lecture was awesome. However, now that we understand the principles of cloud formation, it would be amazing to have a lecture explaining how other types of clouds are formed (cirrus, stratus, and all their hybrids). We understand cumulus and cumulus-nimbus, but the others weren’t covered in the course 😞
groso Mel! gracias!
A clear, beautiful and entertainig lecture.
Thanks!
Well done! Thank you!
Amazing!
Greetings from Brasil. Very interesting
Could you do a video on hurricanes and how they form and sustain themselves? I would love to hear how you explain hurricanes! and if you can explain the difference between midlatitude cyclones and hurricanes. Thank you for these great lectures!
Thanks to you, now I can't look at clouds like a normal person 😂
Very clear lecture. I looked up your web site. Looks like it is still under construction. I have family living in Albuquerque and if possible would enjoy attending one of your workshops on my next visit. I look forward to signing up when you get around to organizing it.
Thanks...I'm right in the middle of changing everything up on my website. There's suddenly more demand for online content due to the virus, so I'm trying to get all of my accompanying materials online for each lecture.
Excellent, thank you!
Thanks - hope it was helpful
@@MelStrong Recommending for all (student) pilots, best overall convection explanation I have seen; well done sir.
No mention of orographic lifting?
Great series!!! I’ve watched several so far. Wish I was actually in class because I’ve got questions!
Well if I was making a Part II for this lecture, I would include things like CAPE, orographic lifting, loaded gun soundings, etc. But I was trying to stick to pure buoyancy here. But yes orographic lifting can help get things started, though you still need upper air instability for the convection to really continue. I think in a later lecture I do talk a little bit about orographic lifting although I may not have used that term with this class.
You can always post questions!
He's always petting some huge kitty. Thats my favorite part.
Don't body-shame my cat. He is proud of his hugeness...
@@MelStrong I had a 22 pounder once. His name was James Donald Kitty (RIP 2004-2016🧡) and he was MAGNIFICENT. Long live the yuge kitties.
@@ralphralpherson9441 Well JDK was a BIG BOY indeed! I lost my big boy a couple weeks ago due to a tumor. He will live forever more on TH-cam I guess.
@Mel Strong At 53:38 cold air mass comes from the north. Why is the cold airmass able to get above the warm air? Cold air is denser, sink below the warm air and lift them up. Like the pattern we know from a cold front followes after warm front. What's the diffence and how did the cold air manage to stay above?
For cumulonimbus clouds to form does the air speeds, at the higher elevations in the atmosphere, have to be below a certain mph for the cumulonimbus cloud to form? Is there a certain mph that these winds can't be?
Thanks!
I had no idea about the cloud suck thing, in aviation there's certain laws for how far away from a cloud you have to be in certain airspaces for VFR flight. I already keep a wide distance from em just to not break those laws, but now I have another reason not to get close!
16:13 image credit: Matt Groening
Mel, could you further explain the importance of the release of latent heat in forming thunderstorms and, how exactly this occurrs? How many degrees(F) does this heat the air (generally) in the cloud?
Thanks for the very vivid lecture! I have one question: The movement of positive charged elements to the top of buildings and other high objects: Is it the effect that leads to the St. Elmo's fire, sometimes?
Yes that's right. Also on sharp objects like plane wings.
Thank you so much for these... Is there a particular lecture where you talk about predicting changes in weather based on cloud patterns?
The only reliable predictions from cloud patters come from frontal systems in the higher latitudes....this is lecture 9
love Pecos Hank!!
I have seen a photo of a thunderstorm cloud, where the rain (at the side of the dark black cloud) came down at a 45°Angle!
Hi Mel, in one of your videos you explained how the altitude to which a Cumulonimbus clouds can grow is limited by the inflection point of temperature between the troposphere and the stratosphere due to the presence of the ozone layer. Considering the fact that there is a gap in the ozone layer above Antarctica, would it possible for Cumulonimbus clouds grow taller there (if the conditions were right)?
Brilliant stuff, Please refer to temperature in Celcius.
Thank you so much for the videos! I'm a PhD student in Physics, nevertheless, stopped here to improve my knowledge on weather for sailing.
Just a thought: you mentioned sound 'shade' what is known as refraction (in Optics first but it's the same for sound waves). It might be possible not to hear thunder from 20 miles, but the sound could come back further away making people crazy cuz actual sound source is out of horizon. I've been told about optical mirage by sailors, so why a sonic one couldn't exist
Yes sound reflects and refracts through the atmosphere. Low frequencies in particular can travel extremely long distances. You get areas of constructive and destructive interference as well so really weird things can happen.
TH-cam documentary: "Air France Flight 447." A weather event involving super cooled water brought down this flight with 228 people.
If the downbursts move fast it negates the winds from the opposite side and its only on the side
excellent info and delivery! as a sailor, how can we mitigate the excess/ deficient electron zones to keep our masts from be the connector of the two zones??
Well the standard thing to do is to have very sharp points, which encourage continuous discharge of electrons. Planes have these as well.
Hi do you have paper reference or some books i can use as source for my research
How hail forms exactly Mel? 🤗😊
What is the physics behind those fuzzy pileus clouds at 13:22?
Is it that the convective updraft of the cumulus displaces a layer of moist air upwards making it reach its dew point?
Yes pretty much. If convection is very strong, then rising currents of air are moving so fast that the column air above cannot get out of the way in time. So an entire layer of air is uplifted and condenses into cloud briefly before it moves away and dissipates.
@@MelStrong Thank you for the answer, makes sense!
Hey you mentioned how the cloud over the airforce base just stays as cloud and doesn’t precipitate? One reason that area could see cloud development and now rain would be that their is too much horizontal wind so it doesn’t allow the cloud to grow vertically to rain? Or low RH level? Any other reasoning?
In the case of the airforce base, yes there is a low-level wind that constantly blows the cloud off the heat source at the surface. But even if there wasn't any wind, it would be unlikely that you would get rain unless you had unstable air aloft. The heat source at the surface can send a plume of warm air upwards only for a short distance - how far it continues to rise depends on how cold the air aloft is.
Mel Strong what’s the necessity of unstable air? Why is it important for convective precipitation?
Unstable air has the condition that if a parcel of air is uplifted, it will continue to rise on its own. This is usually because the air aloft is colder than usual, allowing warm parcels from below to rise easily. In Lecture 5 I go over this somewhat and work out some simple problems as to what happens to a rising parcel of air in different situations. In stable air they sink back down, but in unstable air they continue to rise. In most places in the world, unstable air is the result of a cooler airmass moving in from a colder region. But along the equatorial regions, the intense heat and humidity at the surface lets parcels rise without the addition of cold air aloft.
i can't help but notice you look a lot like scott disick. great video btw!
I'm not sure if that is good or bad but either way I had to Google who he was
What an amazing sidebar in this lecture regarding the para glider who was lifted up to the top of thunderstorm (hail and lightning) and she survived. I was not aware of this story. Incredible how that she survived. Here is a link to the story of Ewa Wisnierska. th-cam.com/video/TEpKNla63Kw/w-d-xo.html
At what altitude the lightening strikes Sir? can we predict this?
I'm not entirely sure what you are asking, but lightning can come from different levels within the cloud. It all depends on the charge distribution in the cloud. So you can have cloud-ground lightning or cloud-cloud lightning or lightning that is within the same cloud. Pockets of charge accumulate in different areas, and when those areas of charge exceed a certain amount, then discharge via lightning will happen. Researchers have flown planes through cumulonimbus to map out where the fields of charge are, and have found so far that each cloud is different.
@@MelStrong wow Sir. Thanks for taking time to reply. Now I got some expert answer.. following your videos.
Is prepicitation rain?
Rain or snow or hail or sleet....
@@MelStrong ok
28:31 impressionante
12:57 shooting star
White cat today love it
Collect all six and win a prize
@@MelStrong you have made me a better person in weather I truly became a weather geek and love it I live eat weather and ordered Luke Howard essay on Weather book from 1803 and his paintings reprints I will make a area in my home in his memory wish you lived next to me I would watch your cats for ya
@@LaRobertos Thank you so much for sharing! Going straight to the 1803 source...that is hardcore. But putting his reprints on your wall? That, my friend, is on another level. Much admiration!
You reference this link in your lecture: worldview.earthdata.nasa.gov/ This is very interesting. I'm curious, do you have or know of a cloud recognition guide for identifying clouds from a view point in space? For example, I cannot distinguish cumulus, altocumulus, or cirrocumulous from space. I suppose I could capture images from below and then compare them to tomorrow's viewpoint with the NASA data since there appears to be a one-day delay. Any ideas?
Cloud identification from space is difficult. One tool they have is Infrared cameras. You have seen probably seen IR animations of clouds as they use them all the time for weather reports on TV - otherwise clouds would be impossible to see in the dark. But if you process that IR data, you can retrieve temperatures for the clouds (called "cloud-top temperatures" in the scientific literature). The temperature tells you the height. So that helps a lot. But, that doesn't solve everything. NASA started a citizen science project called S'COOL (scool.larc.nasa.gov/) that is asking people looking up to identify clouds at particular times, with the idea being that the remote sensing people can use that info to come up with algorithms/deep learning/whatever to identify cloud ID from space. There is a tool there that will send you a picture from space over your location at the time you are looking up so you can compare clouds from above with clouds from below. I'm not sure really how much the citizen science is really being used here, as it seems mostly marketed towards kids.....
@@MelStrong Thanks for the link. I'm interested in the app since I enjoy the outdoors and sky watching. Based upon your IR info I found www.nesdis.noaa.gov/content/imagery-and-data . It appears I can select IR and also water vapor and download an image representing the last 24 hours. I think I can scrape these images with code to detect info over a specific location by sampling the pixel colors.
25:19 the microburst looks like a tree stump? Lol 😂
cat
The level of detail is insane! I had no idea about the Bergeron process! I thought rain precipitated from thin air... WRONG! only in the tropics. 🤪
That’s not how I have understood thunder to happen. I thought it super heated the air and the air moves at supersonic speed...
That is more or less correct. The small column of air is superheated and expands briefly before the atmosphere slaps back together. These two events create a shock wave that then propagates away from the lightning bolt. This shock wave can be supersonic for a little ways but then quickly slows to the speed of sound. The air itself is not moving except for those air molecules within the column of superheated air.
kitty
Your name almost sounds like “maelstrom” and that tickles me.
why is there a different cat 😭
i watch for the cat content.