TechStuff Classic:Weather Tech, Part 1

this has to do with weather technology. In fact, it's called Weather Tech Part one, and that tells you what next week's classic episode will be. So sit back and enjoy WeatherTech Part one from April twentieth, twenty sixteen. Today we're gonna talk about weather because of a listener request. This comes from Dress Sayan and dree I am so sorry if I mispronounced your name. I actually asked Dreese how to pronounce this name, and I can only hope

I got close. But here's what Dreas had to say. Hey, I just wanted to ask Slash request something about the podcast. See a while back, I had a conversation with my dad. He commented how amazing it was these days. He can just check a website that will pretty accurately tell him whether it's going to rain in the next few hours. And where I said that, it doesn't seem like that's

amazing progress to me. After all, when he was a kid in the sixties, they would report if it would rain the next day, and now it's just that we've got it down to a few hours instead of twenty four hours ahead. He laughed and said the weather report back then was pretty much a joke. Anyway, this gave me a lot to think about, and it seemed like something to learn about from the Tech Stuff podcast, because, to be honest, I have no clue how weather is

accurately predicted. It's just always been there for me. So we're gonna talk about weather forecasting, meteorology, the technology used to make predictions, what those predictions actually mean. We're going to break all that down. There will probably be at least one or two references to how weather report. Weather reports are still largely the work of some estimations and best guesses, because, as it turns out, whether it's incredibly complicated, but hopefully by the end of it, you'll have a

little bit more sympathy for meteorologists. Right right as opposed to my friend who in college wrote an essay explaining what level of hell meteorologists should inhabit based upon Dante's Inferno, which was kind of funny, but also I'm sure meteorologists

find it less. So so let's start off with just talking about the history of predicting weather, and really you have to go all the way back to early human civilization, because, as it turns out, one of the most important factors that play a part in this is the fact that we humans are pretty good at recognizing patterns. Right, So when something happens over and over, we take note of it, and we start to look at the other things that are happening over and over, and then we start to

draw some hypotheses. For example, we might think that one thing could cause the next thing, or we might think one thing simply indicates the next thing is going to happen. Here's a simple example. Let's say that you are a shepherd and you notice that the flock of sheep act in a certain odd way every time it's about to rain.

You might either come to the conclusion that the sheep are able to sense the rain before it actually happens, and therefore that as an indicator that is going to rain, or you might come to the conclusion that, in fact, the sheep are causing it to rain. That's probably not true. There are two ways to take that. Yeah. Yeah, But eventually, through these observations you start to eliminate possibilities and you

start to draw some conclusions. Now, in early human civilizations, we're talking about very broad conclusions, things like you notice that in general, the weather gets cooler as the year goes on. You might not even have a year at this point. You may just think, as time passes, the weather gets cooler until it gets really cold, and after it's really cold for a while, it starts to get warm again, and then it gets really warm, and then it gets hot, and then the whole cycle starts over.

And you may also notice that the stars the way

the stars are, you can tell that they are. It's a slightly different view as this time goes on, and you start to associate, oh, when the stars get into this slow you know, this kind of configuration, It means we're getting toward the time when we should really harvest food, because we're about to go into the winter months and otherwise we're going to lose everything we've been growing, or when it's this time we should start planting food because it's the best time for us to get a big yield.

Later on climate, Yeah, and you start to figure out you build out a calendar based on this, and that calendar would be fairly rough, you know, wouldn't necessarily be reflective of an actual full year, but it would be more like an indicator of what you should be expecting in the next coming time. Right, So that's your basic like big picture stuff, using things like the way animals react or certain smells that you might detect before a rainstorm. That would be sort of the more acute weather type

stuff as opposed to the seasonal type stuff. And you start to draw those conclusions too, and together you start building out general rules that tell you if this one thing is happening, then here's what you should expect. This sort of pattern recognition. And in fact, today some of our data still relies on that principle. It's just that we have way more information now at a much higher

precision than ancient humans did. And speaking of that, I read that there are certain Aboriginal tribes that have been observing their weather patterns for over eighteen thousand generations, so that kind of gives you a sense of how far back this goes. Yeah, and and of course, you know, if you're talking about a very specific region, like a very relatively small geographic area, you could have a pretty accurate idea of what to expect based upon those sorts

of observations. They might not be presented in the super cool, high tech way that modern meteorology tends to present it, but that doesn't make it any less valid necessarily. It may be a little more rough around the edges. But if you can still tell me that, hey, in three days we're going to get some rain, and three days later it rains, and you do that reliably, that's pretty impressive. Right.

So if you want to start looking at people who were really thinking about whether in kind of almost a scientific sense, and one of the first people you would have to look at his Aristotle, big brain Aristotle. He was quite the thinker. He wrote about whether in Meteorologica, and he came up with a bunch of hypotheses, some column theories, I would say hypotheses, because none of these, not all of these proved true. They came up with some hypotheses about how stuff like rain and hail, and

wind and clouds and thunder and lightning and hurricanes. What made them happen, how did they behave what were the rules that governed them? And some of his ideas were mostly right and some of his ideas were way off. But the problem was without ways to measure the various metrics associated with weather, it was kind of impossible to say one way or the other. So for about two thousand years, everyone kind of just went with it because you didn't have any way of proving or disproving any

of the individual ideas. But you need a basis, Yeah, you know, at least it was something. It was at least something to work from. It was just it was just a question of time. When would people develop tools that would allow them to put these ideas to the test and either see which ones are mostly right but maybe need some tweaking, or in which ones you can just completely throw out the window, Which brings us up to the Renaissance, one of my favorite time periods. As

it turns out, spend a lot of time there. Our listeners can't see. But right now Jonathan has a handlebar mustache, a giant handlebar mustache, because the character I play in the Georgia Renaissance Festival has such a mustache, and I will be performing as that character the day after we record this episode. It's opening weekend for the Georgia Renaissance Festival. Would you say that someone might have a handlebar mustache in the fifteenth century, around the time of German philosopher

Nicholas of Cusa, It's quite possible. I mean, there's no reason they could not have one. It's not like there were social taboos about such things. Yeah. So this philosopher, Nicholas of Cusa, designed a device to measure the amount of moisture in the air, and we call these hygrometers. These are it's really kind of a way of measuring humidity, which here in Atlanta you can pretty much just says

it's humid. It's so humid. Yeah, the humidity in Atlanta is brutal, to the point where I have friends who come in from Texas, where the temperatures in Texas can get twenty degrees hotter than it gets here in Atlanta. But because Texas has relatively low humidity through most of the state, they think the weather here is way worse, like, way more difficult to deal with, But how do you measure that? And he came up with an interesting idea.

Now there's there's no indication that he ever built the device he came up with, but he said, what you do is you take a set of balanced scales, so you know what those look like. They have a little dish on either side, and on one side you put a large amount of wool, and on the other side you put some weights. He said stones. Other people later on said discs of wax didn't really matter. It just had to be a counterweight of some sort. Now, the purpose of the wool is to soak up moisture in

the atmosphere, which would make the wool get heavier. This is what Nicholas was saying. Like, the wool will get heavier as it soaks up water from the air, and you'll be able to tell that because the scales will start to shift and you'll see that the side with the wool will start to get heavier. Then if it dries out, if the weather gets dry, the wool will start to lose moisture. It will evaporate, and you'll start to see that side of the scale moving up. It'll

get lighter. Now, he never built that, But another big thinker of the Renaissance did get around to it, Leonardo da Vinci. Yes, he did everything. Yeah, when he wasn't building helicopters or designing tanks, which he never built, but he did design. He designed a tank, and he designed a really weird I think, gosh, it was something like a thirty three barrel gun, didn't he I think a

diving suit as well. Pretty much any any sort of thing that in the Renaissance would sound like it's science fiction. She had some sort of hand in. He probably has a primitive tablet schematic somewhere. Yeah. Yeah, he probably at one point came out to his patrons and showed a wooden slate and talked about how if you ran your fingers across it you could you could paginate through. And then he'd say, I think you're gonna love it, and

maybe even did a one more thing. So that was the first kind of weather related instrument that people were really thinking about. Another would come in the seventeenth century early sixteen hundreds, usually put around sixteen oh three, when physicist Galileo Galile created a thermoscope, which is sort of a predecessor to a thermometer. And it was a pretty simple idea. So you start with a container that has a small amount of liquid in it, usually water. That's

your base. And then you also have a kind of a hollow tube of glass that ends in a bulb, so like a larger bulb at one end and open on the other end. And you could do something like warm the bulb if you want too, in your hands. But then you would put the bulb. You would put the tube into the small container of water. The bulb would be suspended above it. Usually the hollow straw like tube would be long enough, you know, several inches long.

You could then observe that as the temperature of the bulb changed, the level of water in the tube would either go up or go down. And this is because the air inside the tube is either expanding or contracting, depending upon whether it's heating up or cooling down. And this wasn't a thermometer, but it was. It was interesting,

and it was once again a start. Yeah. Later on someone looked at Galileo's little invention and said, what if we put like markings on the tube so you could say how many steps up or down the tube it went. Then we could even give indications of how much warmer or cooler. You could say it's four steps warmer or four steps cooler. That became the basis of the thermometer. So and that didn't take long. It was within about

fifty years that you had the first working thermometers. Following this kind of proof of concept thermoscopy, there was also there is the Galilean thermometer. Are you familiar with these? I am not. You've probably seen one. They are the cylindrical glass They're usually very decorative for for like home office desk ers, and but these glass tubes, they are cylindrical. Typically inside they have these these little glass blown glass

balls that contain their own liquid. Often it's a liquid that has dye in it, so they're blue or green or red or whatever. And each one has a little weight attached to it that has a temperature. And what happens is the balls represent different densities of water, and the temperature of the glass tube will change the density

of the water inside the glass tube. And then you'll see whichever ball is at the bottommost of the tube the glass tube, as that represents the general temperature, and they tend to be between like you know, like about five degrees aparts, he might have sixty five degrees seventy seventy five degrees eighty that kind of thing. So whicheveryone's at the lowest point. That's the temperature of the water,

thus the temperature of the area surrounding it. I tend to be used, like I said, as decorations for desks and stuff. Galileo actually did not invent that, but some of his students did. It was several of his students, so that's why it's called a Galilean Thermometer's neat. Yeah. Yeah, it's a very pretty way of seeing, generally speaking, what temperature the tube is and therefore probably what temperature the

surrounding area is. Keeping in mind that water changes temperature more slowly than something like a room would, so it wouldn't be reflected immediately, but it's still kind of interesting. We'll be back with more about weather technology after this quick break. Then we have the This is a very important tool in predicting the weather. So barometer is all about predicting, or not predicting, but measuring atmospheric pressure. So first thing, just in case you weren't aware, the atmosphere

exerts pressure on us. It pushes down. Gravity is technically pulling down on the atmosphere. So the lower you are to the surface of the air, like the closer the lower down and elevation you are, the more pressure you feel from atmosphere. This is why as you climb a mountain or you get on a plane, you experience lower amounts of air pressure. It's also why you have to pressurize aircraft that fly it pretty high altitudes, otherwise you would suffer some pretty rough effects. And on the Earth's

surface the force of gravity. Due to the force of gravity, the pressure is about fourteen point seven pounds per square inch. Yeah, that's a sea level. Yeah, that's what we call an atmosphere of pressure. Right one atmosphere pressure, you look at it at sea level. Specifically, you're looking at it at sea level at fifty nine degrees fahrenheit, which is fifteen degrees celsius. You have to be very specific because temperature will change pressures as you warm up air. Typically this

is just a general rule of thumb. When something warms up, that means molecules are moving. That's the energy of motion. Ultimately, you're making these molecules move faster and that's kind of what heat looks like. So as molecules of air move around more, they spread out more, it becomes less dense. So that would change the atmospheric pressure as well. That's why you have to take temperature into account. When you talk about one atmosphere of pressure. That's very specific. It's

at sea level at that temperature, that's one atmosphere. So that's that's kind of interesting anyway. The first person to actually create a barometer was a guy by the name of Evangelista Torricelli, and his first invention people just called Toricelli's tube, which doesn't seem very dignified. No, it needs a special name. Yeah, but Tori Chelli's tube, it wasn't quite the barometer yet. What he was doing was he was actually experimenting with the concept of vacuums, like creating

a vacuum within a tube or some other container. He was just it was one of those things where we didn't fully understand what that was, how it worked, and so he did this experiment. He was actually friends with Galileo, and Galileo said, hey, Evangelista, I got an idea for you. Why don't you take one of those tubes you've been working with, and fill it with mercury and use that in your vacuum experiments. Will be a lot easier to see than some other liquid. And Tori Chelli says, all right,

I'll give it a shot. So he took a four foot long glass tube and he filled the glass tube with mercury so it was closed on one end, open on the other, and then he inverted the tube into a dish, and the dish had a little bit of mercury at the bottom of it. And it showed that this the fact that the top of the tube, you know, like the mercury went all the way up this four foot tube. The liquid didn't just come rushing out and spill everywhere, right, because the vacuum is what held it

in place. And he says, look, see, I was so smart. This shows that there's something working here. We're gonna really explore this. But then he noticed something else that was really interesting. He noticed that despite the fact that the tube could stay upright and the liquid would stay in there from day to day, there were variations and how high the mercury would be in the tube. And it wasn't just sinking down. It's not like it was leaking

over the course of a week. So like you come back and it's a couple inches lower, and then the next day it's a couple inches lower. It wasn't like that. Some days it was actually higher. And he started thinking, well, what the heck would cause the mercury to go up or down this tube? The atmosphere that's it. The atmospheric pressure pressing down on the liquid in the dish. That's what determined whether the well, that's what to the height

of the mercury inside the tube. So on days with higher atmospheric pressure, it pushes down on that exposed liquid within the dish and it forces that liquid to go up the tube, and so the height of the liquid inside the tube goes up. On days where atmospheric pressure is lower, some of that liquid comes down and starts filling up the dish until it reaches that kind of equilibrium. And then he's so he said, hey, this shows that the atmosphere itself exerts pressure. And not only that, but

the pressure is not consistent day to day. It can change. And in sixteen forty four Torchelli built the first mercury barometer. So now he was building something specifically to measure this thing, because before he was really demonstrating the concept of vacuums. So now we've got the barometer, we've got the thermometer, we've got the hygrometer, essential things. Yeah, these are the

basics for taking measurements about weather. And at that point it was really the start of gathering enough information so that meteorology, the science of meteorology, could actually exist, right because now we could not just observe patterns, we could actually quantify what was happening. And by quantifying it, we could get to this level of precision where we could start to draw more specific conclusions as to what would

or would not happen based upon current conditions. So, all that being said, we still have some issues predicting weather. So why is that? Well, like I said before, it's complicated. So here's the thing. Our atmosphere is fluid. It's a gas, but it behaves via fluid dynamics. Dylan, have you ever

studied fluid dynamics, I don't believe. So I studied them in physics and they are rutally difficult to comprehend because it can get so there's so many factors that can affect a fluid, so and the Earth has a whole bunch of them happening at once. Right. First of all, there's this big ball of plasma that's about eight and a half light minutes away from us. It's called the Sun. Yeah, you know, on nice days you might even get a

glimpse of it. So the Sun provides obviously a ton of energy to the Earth and so we So the Earth absorbs a lot of solar radiation and that can affect fluid dynamics because you've got a lot of heat coming into a system. On top of that, you've got the Earth. Earth's not standing still, the Earth is rotating. That rotational force creates other fluidic effects in the atmosphere. We'll talk about those specifically when we get to high

and low pressure systems. You've got gravity, which is pulling down on the fluid, so that's another force that's in play. You've got differences in surface temperature on the Earth, so you've got areas where it's very cold versus areas that are very hot. That in turn affects the atmosphere and can change things around. You have air currents a big deal there. That's also partially due to the rotation of

the Earth. You've got mountain ranges which can act as like a windbreaker for certain things that changes the way weather patterns happen. Lots of things that are all in play, and some of these are localized, and some can concern large portions like air movement. Oh yeah, yeah, some of

them are. Some of the effects of these can be felt hundreds of miles from where the thing happened, right, which makes it even harder because as a lady person, you sit there and think, all right, well, you know, because I can't see any clouds on the horizon, I think tonight's going to be all right, And then you could have a very fast moving system coming in due to something that happens well out of sight. It ends up creating a lot of things that could be counterintuitive,

depending upon what you have at your disposal. Like, of course, the more information you have, the better conclusions you can draw in general, assuming that you also know what you're talking about. So let's talk about some of these things. These different major components that shape weather, like atmospheric pressure. So we just talked about that with barometers, But what does that mean? So what is happening? Well, I talked about how you have warm air that has air moving

around a lot. That means it ends up spreading out, it becomes less dense than cold air. You probably have heard the phrase that warm air rises in cold air sinks, not entirely accurate as to what's going on. What's really happening is cold air is more dense than warm air, so cold air comes to take up the space that warm air had, which forces warm to go up. So it's not so simple as warm air rises, cold air sinks.

It's more like, you know, if you've got these big heavy weights at the top, then they're going to come. They want quote unquote want, there's no desire, but they have a tendency to want to move downward, forcing the lighter stuff to go upward. That's pretty much what's happening here. So when you're talking about our atmosphere, you have to keep in mind it's three dimensional. It's not on a

flat plane. That's easy to forget when we look at weather reports, because we're looking typically at a flat map, right that has a bunch of stuff like it's got little flags all over it and little lines around it, and h's and l's, and you're wondering what you know, maybe there's some clouds in there too, and but typically you're looking at a two dimensional representation. But really you have to remember that weather is a three dimensional phenomenon,

so that makes it a little more complicated. Also, you got to remember the water cycles. So cold air can't hold onto moisture the way warm air can. All right, when you have warm air as close to the surface. Let's say you've got some nice, warm, moist air close to the surface of the planet, and cold air is

sinking down forcing the warm air up. As the warm air rises, it's going to start to cool and as it cools, it can no longer hold onto the moisture that it had, which means the moisture starts to condense, water vapor begins to condense. This is how you get clouds and ultimately how you get stuff like precipitation. So

understanding that's important. So now let's imagine way up in the atmosphere, at the top level of where our weather happens, we have these massive air currents now in cases where air currents are converging together, so you've got two air currents that are meeting up. They start to force air out of the way. Now air can't go any further up to go down, it has to go down. That's the only place to go. So that air coming down

increases air pressure at that location. You have air moving down towards the surface of the Earth pushing down, your air pressure goes up. So an area of high pressure. You know what kind of weather you typically see in an area of high pressure? Clear, dry weather, Yes, exactly. So when you have high pressure system, it's typically pushing the moisture out of the way. It's it's it tends and we have to use phrases like tens or words

like tens because it's not every case is equal. But it tends to be cooler, it tends to be sunny, it tends to have less wind than low pressure systems. So this high pressure system creates pleasant weather. Low pressure systems are different. Oh and also if you were to view this from the sky, like you're above this high pressure system, and if you could see air, first of all, that would be a nightmare. But if you could, you would see that the air is not just coming down

like a column. It's not like it's not like you turn on a spigot of water and water just falls straight down. It's actually turning as the air is sinking right, as this high pressure system forces air downward, and it actually moves in a clockwise direction, which is funny because I was looking at Dylan a second ago and making a twisting motion, but I was doing counterclockwise. But no, it moves in a clockwise direction. This is, by the way, due to the rotational force of the Earth in part.

So you've got this rotating clockwise system that's pushing air downward. That's your high pressure. We got a little bit more about WeatherTech to talk about before we get to that. Let's take another quick break. So that's your nice weather, low pressure. I think you can probably take a wild guess it's gonna mean crummy weather. Yeah, this is where you're getting clouds and rain, and typically you're talking about

air being pulled upward. So why is air getting pulled upward? Well, remember I was talking about those those currents up in the upper atmosphere where they were converging together and forcing air downward. If the currents are moving apart from each other, if they're diverging, they create sort of a vacuum effect over that region, and that starts to pull air upward, creating an area of low pressure. Warm air from the surface gets pulled upward, it starts to cool down and

the water vapor condenses. That's where you start getting those overcast days, the cloudiness, the rain. And on top of that, you're creating since it's a low pressure system, you're creating the opportunity for some pretty hefty winds to move in. Right, Because air is always going to move from an area of high pressure to an area of low pressure. That's

just pure fluid dynamics. It makes a lot of sense if you've got like imagine that you have two water balloons connected to each other, all right, and they are in equilibrium, so they're equally full, not totally full, but equally full. If you're to squeeze one of those, creating an area of high pressure, it forces the water to go to the area of relatively lower pressure. Right, You're forcing water into that second water balloon. Same thing is

true with low pressure systems. You've got a low pressure area, that means any area around it has higher pressure, air is going to want to move into the area of lower pressure. That's where you get winds coming in and it can get pretty breezy. So this one, if you were to look overhead and view the air, it would be rotating in a counterclockwise or whiter shins if you are Shakespearean direction, and the air would be coming into the low pressure system as opposed to coming out like

in high pressure. It would all be moving outward in that clockwise direction, with low pressure inward in a counterclockwise direction. Now, the reason why I even bring this up is because it's important to understand how high at pressure and low pressure affect weather. So things like the wind speed, the potential for precipitation or lack of precipitation, all of those would play a part. And it's important for you to know what the pressure is of that region in order

for you to make any sort of forecast. So the barometers would be the tools you would use to get those those measurements. Now, the old style barometers, the mercury ones, use fluid to indicate changes in pressure, sort of like what we were talking about with Evangelista's barometer, simply just looking to see where the level is. So area of high pressure pushes the liquid further up, you would say that pressure is rising and weather it's probably going to

be pretty nice. In fact, if you ever have seen one of those old school barometers, it probably has like sunny like a little drawing of sunshine toward the top of it where the level goes up. If the if the glass is falling, if the mercury is going down the tube, then that would suggest low pressure, which suggests cloudy, nasty weather. But we also have other types of barometers. In fact, not a lot of people use the mercury ones anymore. Don't know. If you know this, Dylan, mercury

is not the best thing to use. It's a little toxic. Yeah, it'll drive you crazy, you'll go mad as a hatter, but yeah. They they're also aneroid barometers, which were invented in the nineteenth century eighteen hundreds. In other words, these have a tiny little metal box and the sides are all made out of a flexible metal, and changes in pressure either push the sides of the box inward or allow the sides of the box to flex outward. That in turn is connect to tiny little levers which are

connected to a needle. And then you look at your device. It can look like a little stop watch actually, and you see where the needle is and that tells you where the atmospheric pressure is at right, or you could use digital barometers, which have little pressure sensitive transducers that essentially do the same thing. They're just doing it with a transducer as opposed to an actual physical metal box. And how do we talk about these measurements, Well, it

depends upon what system you're looking at. But typically weather men, meteorologists I should say weather people. I suppose that sounds like a good term. Yeah, yeah, weather people inclusive term. Yeah, a meteorologist is probably more accurate, but they use They tend to use millibars to describe atmospheric pressure, but in the US. Here in the US, we sometimes refer to inches of mercury, because darn it, we like that system.

The standard scientific unit is the pascal or PA, and then there is, of course the one atmospheric pressure type approach. That's not terribly useful if you're talking about tiny changes in atmospheric pressure, like yeah, it's a point zero zero zero six atmosphere change doesn't help you very much. To me. It's kind of like measuring temperatures and celsius. It works great if you're boiling water, but if you're doing anything else, Celsius to me is just it's too brute force an

approach to describe boil water. So that's perfect, right, that's really whenever I go by Dylan's desk, it's just a pot of boiling water and some photos on a screen and that's about it. So then we have temperature and moisture that those are the other two really big components. So a large body of air that has a similar temperature and moisture throughout that body of air is called an air mass. So when two air masses are near one another, they are separated by a thing called a front. Right.

So you've heard of cold fronts and warm fronts obviously, right, So we'll focus on the United States. We have four major types of air masses that affect our weather here in the United States. This is not the way it is everywhere. These are the four that in general affect our weather. So you've got continental polar air masses cold and dry yep. Continental tropical air masses hot and dry, yes, which by the way, only happened in the summer and

come up from Central America. That makes sense. Yeah, Then you have maritime polar cool and moist yeah. And boy, I'm so sorry for you people out there who hate the word moist, and then maritime tropical, warm and moist. There it is again. Yeah, so your content in minal polar air masses, those tend to come from our friends to the North Canada. They ship us their poutine, they're Tim Horton's coffee, and their continental polar air masses. Don't

bring up Tim Hortons. I'm still bummed that there's not one here. I'm actually still look Canada. I poke a lot of fun, but I fully admit Tim Hortons is a phenomenal chain, a national treasure. I would welcome it with open arms to come here to Atlanta. Just throwing it out there. Your continental tropical, like I said, comes up through Central America and typically only affects our weather in the summer. Maritime polar that tends to come from the far northeast. So we're talking like in the New

England that area maritime tropical pretty much everywhere else. And by tropical when we say hot or warm and moist, we don't necessarily mean like it feels like you're in the Caribbean. It just means not cold. Right, So the fronts tell us what sort of air is moving into an area, so a warm front. First of all, they tend to move pretty slowly. Warm fronts are not known for moving through an area quickly, and they bring lots of rain because warm fronts are pushing out cold air.

So imagine you've got a massive cold air in an area. A warm front is coming in that warm air when it encounters the cold air that's already in that region, it's the warm air's inclination is to kind of go up the cold air like a ramp because again, the cold air is more dense, right, so the warm air

can't just push it out of the way. The warm aare is less dense than the cold air, but it can start to go up on top of it, which means the warm are starts to cool down exactly, and that's why we get rain at the edge of a warm front. So they move pretty slowly because warm air just doesn't push cold air out very efficiently, and we get a lot of precipitation. Cold fronts where cold air replaces warm air, move faster and tend to have intense

but short thunderstorms and other precipitation. As the front moves in and the weather tends to clear up pretty shortly thereafter. The reason for this is, imagine you've got a massive cold air moving in, you have warm air in the region. The cold air is going to almost act like a shovel scooping up that warm air, pushing it up into the upper levels of the atmosphere, of the lower level of the atmosphere, but the upper side of it, which

cools that air down very quickly. Because of that quick cooling, you get things like bigger rainstorms thunderstorms, but they tend to happen very quickly, and then once the front has moved through, things are okay again. Spend a summer in Atlanta and you will see this phenomenon repeatedly. Right like you there was. There are times where if it's a particularly humid month, you might be able to set your watch by when the thunderstorm is going to come through.

Any extreme extreme versions of it as well, not not not disaster level, but you'll see quick intense thunderstorms with hail and heavy rains and they will be gone in an hour or two yep, and then it just becomes a steam bath for the city. That's Atlanta most of the time. Yeah, but it's particularly bad about an hour after a thunderstorm. It's probably the most miserable Atlanta feels, right,

because it's just it's like walking into a steam room. Yes, So again, the reason for that fast violent weather is just the speed at which that warm air is being pushed up and cooled down so that it can no longer hold on to all this moisture that was once part of it, and it has to go somewhere, so it lands on us. So that's kind of interesting. They're also stationary fronts. Stationary fronts are when two fronts just kind of collide and that's it. They're just there. It's

gonna stick around for a while. You'll have a lot of rain. Typically sounds like the traffic jam of fronts. Yeah. And then there's occluded fronts, and that's when a warm front gets caught between two cooler air masses. So the warm front gets pushed up and we get a lot of intense thunderstorms with occluded fronts. Two. Hope you enjoyed that classic episode of tech stuff from twenty sixteen, Weather

Tech Part One. Obviously next week we will have Weather Tech Part two as our classic episode, so make sure you come back and listen to that. If you have suggestions for future topics for tech Stuff, please reach out to me and let me know. You can go over to Twitter and tweet me at tech stuff HSW, or you can download the iHeartRadio app. It's free to download.

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