all right well hello my name is Dan Treiber I am the meteorologist and instructor for this course I'm ecstatic that you decided to take this course and I'm excited to to be able to instruct so this has always been a passion of mine whether in general meteorology in general it's always been a passion of mine and so I'm excited to share that wealth of knowledge with you this first set of slides is a set of slides that I will give it just about any weather talk that I do in any course that I teach it's somewhat lengthy but it develops a good baseline understanding of the meteorological environment but it helps you understand the the foundation so that we can build upon it and further their lectures and and the lectures to come so it is a it's it's a good amount of knowledge you may have to watch it twice because I'm going to feed you a lot of information very very quickly but I strongly recommend that you find a good understanding of it before we move on in the course or in this discussion because everything that I teach you from here on out is gonna build upon this so with that being said I'll tell you a little bit about me I've been practicing meteorology since 2012 I graduated from Embry Riddle Aeronautical University in Arizona in 2012 and then I got my masters as well I spent about six years a little over six years in the Air Force as an Air Force meteorologist I also during that time was stationed with the army and worked with the Army on division staff and the knight also a meteorological consultant with a business that I started called small town weather and you may be taking this class in reference to something you saw from from my small town weather outrage today I do so anyway however you got here I'm just excited to be here with you and I'm excited to share the knowledge and experience that I have an aviation meteorology and among other different facets of meteorology with you so hopefully you get a lot out of this class so let's go ahead and begin with the the basic foundation of how weather works the first thing that I want you to understand and weather is actually a very very easy concept how weather exists is not a very complicated the thing it's actually very easy to understand so literally in a matter of just a few slides in a few minutes you're gonna it's a hopefully it's gonna all come together for you it's it's not very very difficult and honestly this is the way that I wish it was taught when I went to college but I'm gonna teach it to you here real quick so it make things very very simple weather would not occur if two things didn't happen the first thing is is if there was no sunshine the Sun was not shining there would be no weather the second thing is is if the earth was not curved there would also be no weather and the reason that it is is because as the Sun shines it shines on the curved earth you can see that in that first diagram there because it shines differently at every different place on earth and then all of our elements of this earth water trees plants dirt sand all of that every one of those absorbs and reflects heat differently the heating at any given point on the earth is going to be different at any given time so we have you know it's on a hot sunny day you go and you eat touch your your car that's parked outside it's gonna it's gonna be pretty hot it may even burn you then you go you go into the grass or you maybe you go jump in a swimming pool and it's cooler it's much cooler well everything on earth is like that it's heated differently all at different times in the different degrees and in different capacities and so there's always going to be a temperature difference across the globe it's sunny during one time of the day it's on one side of the globe well it's nighttime you know on the other side of the globe and there's always always gonna be a temperature difference there so the globe is being heated differently all the time in every place and so with that it changes the amount of pressure that's that's being applied on the surface to the earth at all times we look at this next slide here you'll see there's a very simple formula it's called the ideal gas law but it's very very simple to understand we understand pressure we see that on a wet a map it's high pressure today it's low pressure today right so we understand pressure has a lot to do with weather then we also I just talked about temperature on the other side of that equation there that PE is for pressure the little P it's actually a row it's a Greek letter but net that's density but well let's just look at pressure right now P it's for pressure T is for temperature nini notice how they're opposite sides of the equation and that's because they are proportionate to each other if temperature goes up pressure goes up if temperature goes down pressure goes down so what happens when you have two different temperatures in two different locations well then you're gonna have two different pressures in two different locations which mean one is gonna be higher and the other is going to be lower it's just the way it works and so that is the fundamental a baseline baseline how weather begins to work the difference between those two pressures is called the pressure gradient now the pressure gradient is is a force it's a force of nature and the way that we experience the pressure gradient from day to day because unless you're flying up in an airplane and your ears start popping or something like that you kind of maybe realize there's a little difference in pressure but on the horizontal field is a fear just driving between Los Angeles and New York you might not notice too much of a pressure difference right but there's probably several different high pressures and low pressures across the country at any given time so the way we experience the pressure gradient in most cases is by the strength of the wind the pressure gradient force drives the wind wind drives cooler temperatures warmer temperatures it pushes moisture in from the oceans and other bodies of water like I said you get a cold front comes through and it gets cold behind the cold front because the wind is pushing cold air from the north and so with this just a simple temperature difference creating a pressure difference now all of a sudden we have wind and wind is what carries most of the weather usually when it's windy outside man that's got a stormy outsider's home and it's breezy out there you know something's going on with the weather right okay cool now let's look into three dimensions let's look at that the jars that we have down here in the bottom of the slide the high pressure and the low pressure we got to think three dimensionally high pressure we call it high pressures because the air is sinking in the verdict it's if you were to apply more pressure to the liquid in that jar and squeeze it squeeze it together that equals high pressure so in high pressure we have sinking air in the atmosphere we're in low pressure there's rising air now all of a sudden all those molecules in the air can rise through that entire picture of water so not only does air flow from high pressure to low pressure just like a basketball that's that's filled up a bike tire car tire that's filled up with air you put a hole in it it's going to deflate because there's higher pressure in the tire or the basketball then there is outside it'd be convenient if the air went in when you punch the hole in it but that's just not what happens because air always flows from high pressure to low pressure also in high pressure and low pressure the air has a vertical component to it so not only is it flowing horizontally but it is also going to be flowing vertically and high pressure the air is gonna be sinking and low pressure the air is going to be rising now I mentioned that air always is going to flow from high pressure to low pressure but if you look at the map of the upper left corner and the weather map up there you'll see that the air seems to be flowing around the pressure and that's definitely true especially as you move further and further aloft in the atmosphere and it's because of the Coriolis force so yes air is going to flow from high pressure to low pressure but it's not gonna flow directly from high pressure to low pressure especially as you move a lot and that's because as as as wind travels especially in the northern hemisphere is as wind travels it's going to curve to the right because the Bissman of the earth it's how the Coriolis effect works it's gonna be opposite in the southern hemisphere it'll move to the left so as you look at weather maps if you look at the weather map at the surface a lot of times you'll see a little bit more of a direct flow from high pressure to low pressure and you'll still see a little bit of curve especially out over the oceans but you'll see a little bit more direct flow from high pressure to low pressure but as you move a loft if you look at weather maps aloft you'll start to see this this curve flow around high pressure and low pressure it's gonna be clockwise around high pressure and counterclockwise around low pressure and then opposite of that in the southern hemisphere I talked about the three-dimensional flow a little bit in the previous slide but here's just an the graphic of how it works like I said low-pressure there's gonna be rising air there's gonna be converging air in the low levels at the surface of a low-pressure and it's gonna be rising and that makes sense if it's there's rising air then there's creating a void or low pressure a void is just another word for low pressure a low pressure there at the surface because the air is rising just like that and high pressure if there's a high pressure at the surface there's it let's do the sinking air now sudden the void is going to be aloft the low pressure will be aloft but the high pressure will be at the surface because of the seeking air and the wind will be flowing away from the high pressure forward the low pressure so hopefully that little graphic makes a little bit more sense the big thing you got to understand is that if there is a low pressure at the surface there's going to be a high pressure aloft above it and vice versa if there's a high pressure at the surface there's going to be a low pressure aloft above it and that's because you can't have too low pressures at the ends of the same pipe if I have any plumbers out there the air is always gonna blow from one end to the other end of a pipe or the water in your kitchen sink the water gonna go it's gonna flow from one end to the other end if it doesn't flow from one end to the other one do what do you say oh I lost water pressure okay well the atmosphere the air is always gonna blow from one place to another place otherwise you don't have any pressure gradient and so just like in the horizontal plane the airs always gonna blow from high pressure to low pressure it does the same in the vertical if there's high pressure aloft there's gonna be low pressure at the surface if there's low pressure aloft there's gonna be high pressure at the surface hopefully that makes sense so there are four main types of fronts and weather and I actually talked about five I know I said there's four but there's actually kind of a fifth I'm gonna talk about here in a minute but I'm gonna go walk through the main four and we're talking about warm front cold front stationary front and occluded front the warm front first the warm front it generally blows from south to north eighth may blow Southwest lead to northeasterly but we got to think where is the warm error going to come from for that warm front the warm air is gonna follow that warm front it's generally be a little bit moist to warm moisture where it is warm moist air come from in the northern hemisphere but save the equator right that's where the the warmest air is gonna be you know closer lower latitudes it's going to have the warmest moist air especially in the in the eastern half of the United States where you've got the warm Gulf of Mexico and it's a good fuel for a warm front so warm air is always almost always gonna come from the south if you live in the northern hemisphere and so the you get dis of Italy air behind the warm front it's generally gonna be moist you're generally gonna see some clouds with it it can be a little bit windy especially overnight but the biggest thing is the easiest way you can tell you had a warm front coming through is is there's going to be all of a sudden you notice wow it's gotten a lot more hot and muggy and that's that's the president of a warm front coming through you couple that with the with the south the southerly winds yeah it's probably a warm front now a cold front again it's gonna be bringing an air mass change but where does cold air come from but the north right the north-northwest is generally what we see in the northern hemisphere we see cooler air coming when you know all weather in the northern hemisphere unless you're very near to the equator like in the tropics almost all weather is going to move from west to east that's why it's always gonna snow in the Rocky Mountains before it snows in the Great Plains that's just the way it works so we think it's gonna have a westerly component to it but the double cold air comes from essentially the north the Arctic so the cold front comes through it brings drier and colder air there are always some exceptions but the biggest thing is is if in the middle of winter time you get this northwesterly wind it gets colder noticeably colder sometimes I've seen to drop 20 and 30 degrees in a matter of an hour noticeably colder and then you notice that the air just and then is moist anymore it isn't as muggy anymore that's because a cold front went through some folks know it as a blue northern farmers and ranchers you know older time blue north or right you know it's it's because when you got to his north wind and this guy turned blue and because you got drier and colder and in anyway so that's that's a cold front that's how he's gonna come after the warm front so you'll notice right before a cold front comes through it's warm and muggy and all of a sudden this cold front comes through gets windy that wind changes to the north and I'll send it as cooler you gotta put on a jacket a lot of times we can see storm development along the cold front as well I'll get into a little bit of that later but anyway that's how you would know a cold front northwesterly winds colder drier stationary front is generally we'll see it on the tail end of a cold front although we could see it on a tail end of a warm front as well the stationary front is exactly what it sounds like it's just a separate enough to air masses it's a front but it's just not moving it's stationary all fronts are separation of air masses meaning that there's got to be either cold and dry on one side hot and moist on the other side something where you can tell one really noticeable difference between what kind of air mman as you're sitting in wow it's hot and muggy okay that's an air mass okay so maritime tropical but it's hot and muggy that's what we'll call it it's hot and muggy on one side and it's it's brisk it's cold it's dry on the other side there's a front and that's separating those two things there needs to be the only thing other thing that can separate two air masses is mountains and so you know if we assume that there's no mountains there especially in the Great Plains where there's really no mountains there and you see this big air man has changed there's probably going to be front to there somewhere my stationary front separates those two air masses generally it's going to be some sort of cold airmass in some sort of hot air mass but it just doesn't move much there's generally some sort of cloud development sometime storm development along a stationary front because the atmosphere just wants to equalize itself it doesn't like having this barrier between two air masses it's trying to get to what you call thermodynamic equilibrium but it's trying to to make everything the same temperature it's trying to make everything the same pressure and make everything the same temperature we know that it's not possible but it's trying to and that's when you would start to see storm development it's generally not very windy weather unless you're right inside a storm or something like that but that's a lot of times you'll notice a difference from one side of a stationary front to another stead of a stationary front an occluded front is a little bit more difficult when a lot of a lot of folks have a hard time trying to understand what an occluded front is but it's actually very simple a cold front is going to move faster than a warm front and that's that's because the cold front has high pressure behind it the warm front generally has a little bit lower pressure behind it high pressure is applying more pressure to the back of the cold front and so it's going to move a little bit faster than that warm front is especially gonna catch up when it catches up to that warm front it comes it cuts off the food essentially to the low pressure system and then you get what you call this occluded front a clue the front generally separates cold air from other cold air and so you'll see definitely see an air mass change usually it's gonna be cooler moister air on one side and cooler drier air on the other side but this is where you're going to see your worst winter storms your blizzards your Nor'easters your freezing rain events will generally happen kind of right where that cold front the warfarin include the front all come together so just think cold weather a lot of snow or ice or something in there it's gonna be right along where that cold front is definitely be cloudy probably thick clouds and a lot of the like I said the worst winter storms they're gonna be somewhere right there near where the occluded front is now the last front that I want to talk about it this one isn't technically a front because in order to be a front it generally has to be associated with a a low-pressure system and the jet stream the jet stream cuts right through a low-pressure system when we're talking about winter winter low-pressure system it's fueled by the jet stream I won't get into all the science behind that but that's generally how you would identify ok this is not just a cold wave of air it's it's really a this is a cold front or this is not just a warm push of air it's a warm front the dryline on the other hand does not have to be associated with a low-pressure it does not have to be associated with the jet stream a lot of the times it is associated with a low-pressure system though but doesn't have to be the the dry line is a lot like a more or less a stationary front and it's almost always going to be through the central plains you know it's going to extend through Texas and then generally up into Oklahoma Kansas I've seen it all the way up to South Dakota before and and I'll explain a little bit more of why white forms there you will not usually see a dry line in the mountains you'll not see on the East Coast it's just going to be in the central United States and that's because it's separating the desert air from Arizona and New Mexico and the hot desert air from the warm moist air in the Gulf of Mexico they're both warm climate zones but one is very dry and the other is very moist and there's got to be something that separates those two and that's where the dry line comes in the dry line like I said it's very common through the portions of West Texas and there can be some bad storms that blow up along that dry line as the air in the atmosphere is trying to reach an equilibrium between the warm and moist into warm and dry like I said it just wants to even it all out but the only way you can figure out how to do that is to cause storms and so other times you can see severe weather right along the dry line it's multiplied when there's a cold front that intersects with the dry line now sand do you not just have dry moist air that they're battling it out now you got cold drier and warm moist air that are battling it out and there's there's more players on the battlefield if you will so that's the last type of front that I wanted to talk about it's very very important especially if you live in the southern southern plains alright this next slide can get really really complicated and I don't want it to be so I'm gonna make it really really short for you as you know you probably learn this in grade school in the troposphere as you go up in altitude to temperature cools that's the troposphere above the troposphere we get a different part of the atmosphere it's called the stratosphere in the stratosphere the temperature actually warms above that we got the mesosphere where the temperature cools again and then above that we got the thermosphere which where the temperature warms again so we got to schooling and then warming and then cooling and warming with height now most weather that we deal with is going to happen almost exclusively in the troposphere we'll see a little bit instead of stratosphere in the lower ends of the stratosphere almost exclusively it's going to happen in the troposphere so we would expect the air to cool at a standard rate as we ascend with height throughout the troposphere and sure enough it does there's a standard rate we call it a standard adiabatic lapse rate and there's a little bit different for dry air as it is for moisture but we have this standard that it should be the thing is is that we all know whether it's the atmosphere is not perfect it's not ideal and so very rarely does it ever follow the exact standard it's gonna be a little bit to the left it's gonna be a little bit to the right it's gonna cool a little bit more it's gonna cool a little bit less am i warm when it supposed to be cooling and cool and this force should be warming that's what weather does the standard is if everything we're perfect and but if everything were perfect you know there wouldn't be any weather so so we have this standard that we kind of follow on it's called the lapse rates but when we start to see air cooling a little bit faster than it should it's called instability when it's warming a little bit faster than it should or warming when it's supposed to be cooling we call that a stable area stea is air stability and so we deal with these areas of stability and instability within the troposphere all the time for example when we see a thunderstorm the air is unstable when we see fog that the air is stable and all that weather is is when a response to trying to make the atmosphere equal the standard but we all know that it's never going to equal a center because it if it ever equaled the standard there would be no weather so it's just kind of a catch-22 we'll go into more of that later it's just important that you understand that nothing in the atmosphere ever really happens by standard or the way it's exactly supposed to happen but that's why weather now I'm gonna keep saying it over and over again but the atmosphere just wants to reach equilibrium and it wants everything to be the same the atmosphere does not like temperature differences it does not like pressure differences it wants everything to be the same it wants equilibrium but even if the world was completely flat and the Sun shined on every piece of the world evenly they would still be weather it still wouldn't be perfect because there's different vegetation there's water there's mountains there's forests there's all sorts of different types of elements within the atmosphere that are gonna heat and cool and radiate and reflect differently than each other and so there's gonna be gonna be a pressure difference in the temperature difference and all that and therefore there's always gonna be weather we need to understand the difference between those climate zones and and the weather that's in them for example we know it snows in the mountains in the wintertime but the mountains is not whether the snow is the weather the mountains we just expect certain types of weather right the desert we know it's hot and dry in the summertime in the desert and it's cooler and drier and desert in the wintertime but the desert is not whether it's where dry weather occurs that's the difference between the climate and the weather so looking at the United States we can see that about the western half of the United States is primarily some sort of desert or steppe climate semi-arid climate until you get to the the coast to California Oregon Washington Coast you started to see a little bit more Mediterranean you know or more humid climate of some sort and that's because it's just right along the coastline but then we hit the Sierra Nevada at the Cascade Mountains and on the other side of the mountains we see the desert and we see the Rocky Mountains and we see a more of a semi-arid climate and then all the sudden we get right along the central plains and we get now a more humid climate several different types as we go north cuz it's just going to get cooler as we go north but it's all gonna be more humid climate if if we notice where is tornado alley on this picture but right there in the central United States where these climate zones all come together again the weather the the weather is just a response to the atmosphere trying to equalize itself it doesn't like affect it it's got all these climate zones in the United States it doesn't like it and want to equalize it but the only way you can even attempt to equalize it is by causing weather and try to manipulate a climate zone change which is very very hard to do because in order to really manipulate a climate zone change you'd have to remove the mountains in the forests and and all of that you know in the Rocky Mountains so you can't just pick those up with a bulldozer and move them so it's always going to be Mountain this climate in the mountains it's going to be air and on the other side of the mountains it's always going to be like that but the atmosphere wants to at least try to equalize that as best as it can that's why weather exists so the big question is now that we kind of have an understanding of the the science behind the way weather works all weather is I'm gonna keep saying it all weather is is the atmosphere you're trying to equalize everything that's all it is weather is just a response to the atmosphere trying to become equal so now that we understand that how do meteorologists work how do people who study the weather how do we do our jobs right because we know the atmosphere is never going to completely neutralize itself there's always going to be a difference somewhere how do we conduct our business how do we figure out what's going to happen next well this is a great question and the thing is is that meteorology is is a lot like going to the doctor - it's like doctors and meteorologists should it should be like best friends they call a doctor's office a practice I'm a practicing dentist I'm a practicing surgeon whatever you know I don't know much about the medical field but you know that we call it a doctor's practice well meteorologists we practice all okay because it's not an exact science we don't always in fact we almost never know the right answer until it happened just like a doctor doesn't really know what's really wrong with you unless he goes in and does surgery and you know pulls the thing out oh yeah that's cancer you know but then again he doesn't even know if that treatment is gonna be as effective okay so meteorologists work a lot the same way right we kind of have an idea of what's going on but we don't ever really know for sure if the weather that we're saying is going to happen is going to happen or it's gonna happen away we think it's gonna happen we have to do a lot of reacting at the last minute right and we learn from that and that's why we call it a practice but nonetheless we've all made the joke Oh 20% chance of rain 30% chance of rain what does that mean right some folks they'll say hey man it's gonna rain other folks will say uh they always say that you know right it's not gonna mean anything right so I don't know which one you are but it is a physical science right we take a plus B plus C plus D all these factors we kind of jumble them all together and say hmm I have high confidence that it's going to rain today I'm gonna say 80% chance right or I have low confidence that it's going to rain today and say 10% 20% chance something like that right the thing is as meteorologists we have to try to understand how you and the general public are going to understand the way that we are projecting it in other words I can't stand seeing 30% chance of rain on the Weather Channel it doesn't mean really much to me I don't know whether I should take it as oh it's gonna rain somewhere in the area it may or may not rain should I flip a coin I don't know I mean for me it doesn't do me a whole lot of good but meteorologists are still trying to perfect how we deliver things what I tend to do instead of think saying thirty thirty percent chance of rain I'll say rain showers in the area okay that's just another way of saying it but at the end of the day and there's probably gonna be some some rain showers somewhere within you know the nearby area there might be a 30% chance that don't hit you but it's gonna be somewhere in the area and that might be a better way to explain it but we're still trying to figure out it's meteorologists we're still trying to figure out the best way to portray the forecast another thing we got to take into mind is sociology right so what is gonna be the impact this could be a really really bad storm we want to let you know that it is gonna be a bad storm and we'd rather you prepare for it and it not happened and then and not prefer prepare for it and it does happen right so you know winter storms and stuff like that you'll see a lot of that on the on the Weather Channel and a lot of these different weather apps so you know storm Zilla you know it's gonna take over the world and right it's all blown out of proportion but at the end of the day we know it's gonna be bad and so it's okay to hype it up maybe a little bit not too much but hyping up just enough to where okay you know the general public has got the point all right it's gonna be bad right we're if we didn't emphasize it enough then you might not get the point and then you might continue on with in normal daily business and it could be dangerous so we're trying to figure out not only a way you're gonna take it when we say it but then what's the impact of it going to be right and we see it all the time here in Texas when every time there's a hurricane in the Gulf of Mexico you know or even that chance for there to be a hurricane in the Gulf of Mexico and somebody opens their mouth hole too wide that you can't find gasoline in any of the gas stations it just sells out that's usually somebody hyping it up a little too much but then again if we don't tell you about the hurricane and the Gulf of Mexico then nobody's gonna prepare so if it's where's that happy medium gonna be the natural meteorologists are still trying to figure and it's not a perfect science but we're trying to figure it out one of the tools that meteorologists use is satellite we have a lot of tools I'm gonna walk through them but satellite is probably the best tool that we have we can use different types of satellite visible satellite is essentially just what we would see if we went up into a into the space station you know we're up in the space and look back down at the earth it works during the daytime it doesn't work at nighttime because well you can't see at night time right so that's visible satellite infrared satellite actually sees day and night because instead of looking a visual light out of the visual spectrum it looks through the infrared spectrum it's heat-seeking essentially it looks like looks at the temperature of the earth remember I said temperature of the earth is never the same and in any two places really I mean it's always gonna be the oceans I was gonna be a different temperature than Malloy and then the clouds are always gonna be a different temperature than both of those because the clouds are generally above both the ocean and land therefore they're gonna be a little bit different temperature right so it's a good tool to look at the clouds day or night because when it's active looking at is the temperature of the cloud we'll see it on the satellite as as a cloud but the really it's just a temperature reflection of the cloud that we're looking at water vapor looks at the amount of moisture and that's also day or night it'll look at the amount of moisture in the atmosphere generally in the mid and upper levels it uses an infrared spectrum to look at it but it brings out the moisture a little bit more than it brings out the temperature per se radar is a different tool that we use radar has a very short distance that it looks at it's usually about 100 to 200 miles that's about the range that it has but it looks at precipitation in the atmosphere and essentially the the brighter the the color on reflectivity product the heavier the rainfall that's not always true but that's the basic understanding of it and that's because the radar sends out a radio wave the radio wave bounces off the percipitation and it comes back to the radar and a radar says well based on the per turn this is heavy rain or this is a snowflake or this is a hail stone and so that's how radar works it also measures the how fast the particulates and the the hydrometeors the the precipitation how fast it's moving the storms are moving and that'll help us identify tornadoes and you know bad thunderstorms so another huge product that we used it can be used day or night generally it's it's the most useful when it's when it's raining somewhere in the area if it's not raining it doesn't really give us a whole lot of information airport weather observations this is crucial and I have a class on this is maybe actually the class that you're taking when you're when you're watching this and listening to this but airport weather observations are crucial because they give meteorologist an understanding of points all over the United States all over the world exactly what the weather is at that specific Airport and so we can track cold fronts and warm fronts really really well we can track fog we can track wind speeds blizzard conditions we can track all that nothing's better than having you know every couple of miles you know another weather station that just kind of gives us an idea of what the pressure is what the temperature is all of that I mean it's just amazing we can look at satellite but it doesn't tell us exactly what's going on at the surface and what people would be experiencing we can kind of get an idea maybe but you know same thing with radar own training there but how much grain is falling if we kind of have an idea but we don't really know and this we got something at the surface it's plaintive there that can tell us exactly what's going on at that point a lot of airport weather observations and larger airports at commercial airports they are disseminated by weather observers not only to have a machine there that can tell me kind of what's going on but I've actually got a pair of eyeballs as well which is even better than the machine to make sure that the right information is getting disseminated super super useful weather balloons are another important piece of information that meteorologists use in fact I took a whole semester in college and just how to decode and encode these weather balloons I'm not going to go into any real detail on it other than they're really useful to give us a three-dimensional picture of what the atmosphere looks at at a given point they're all over the United States they're actually all over the world there's quite a few in the United State they are usually launched twice daily once in the morning once in the afternoon at least in the United States that's how it works out other parts of the world it'll be different times but it's usually about zero Zulu zero UTC time and 12 UTC time it just works out to morning and evening generally in the United States but more or less it gives us a three-dimensional picture of what the atmosphere looks like super super useful for weather forecasting another tool that meteorologists use our weather forecast models weather forecast models are used to predict the future we can look at satellite radar weather balloons all of that it's a snapshot of what's currently going on but when a forecast models are a good prediction of what will happen in the future we use all of these all of all not just models but everything at our disposal meteorologists will use to forecast the weather it's good to see what's currently going on what the current state of the atmosphere is that's what we use the radar and a satellite and the weather balloons and all that for but to get a good idea of what will happen in the future it's good to have some guidance for what's going to happen in the future for example on the left-hand side here the blue gridded tabular data that that's showing us all sorts of it was a sky condition going to be what the temperature is going to be we can look at there and say oh the high temperature for today is 95 degrees you know that's what this one model is saying we look at spaghetti models that are down there in the bottom you can see all those the yellow and green lines and they're kind of all jumbled up and that the brighter of the of all of them is to average or actually we can get a level of certainty from all the different models and and we can see you know how confident can we be in our forecast so there's a lot of these out there I'm not kind of get all wrapped up in them and explain all them right now or anything like that because that would take a long time but the big thing is is we're not only going to look at what's currently going on in the atmosphere but we're gonna look at these computer-based guidance models to show us okay based on everything that's going on right now this is going to be the most likely event going to happen in the future and and we can move forward with that with some below some level of confidence okay this may be the most important slide we're gonna see in this entire deck of slides I hope you're gonna learn something on every slide but if you don't learn anything else this one is the most important okay there are a lot of weather sources out there there's websites everywhere there's apps for your smartphone everywhere there's all of that and they're all halfway good if you're having a barbecue at your house I really don't care what you when you look at but if you are in a position of authority if you are a city manager an emergency manager an airport manager if you're got something where there's an e run a business and there's a lot of liability you know you're making a decision based on whether that's going to have big impacts where there's gonna be either damage of property hazardous to life that sort of stuff and weather's gonna dictate that look at these authoritative weather sources okay the way to channel is great it's fine if you want to watch The Weather Channel if it's fine if you want to put that in the break room and and all that they like the hype stuff up a lot they like to have shows where they scare people and get their ratings up okay it's cool I mean there's cool stuff but when I'm talking about the protection of life and property the authoritative weather sources is the only one you can really legally go with and have a leg to stand on and that is a National Weather Service National Oceanic and Atmospheric Administration if all Adele falls under the Department of Commerce right now of the United States government okay they're the ones who issue the tornado warnings in a hurricane warnings and the blizzard warnings and all of that sort of stuff that all comes from the National Weather Service now it may be rebroadcast it on the local news channel or The Weather Channel or weather bug or AccuWeather or whatever it may be rebroadcast it on there but the source is the National Weather Service if you're not with any nice to H so if you're in Mexico you're in Canada you're somewhere else there's there's generally a government meteorological source okay your your federal government meteorological office is going to be your authoritative weather source and the important thing is at least within the United states is that if it ever happens that that weather really ruin somebody's day you have a mass casualty incident because of weather you know hazardous severe weather right there's a damage you know millions of billions of dollars worth of damage and all of that and you have to go back and do an investigation about what happened with the weather you know what was a wetter forecast what was when did that tornado a warning first get issued you know what where all the reports of everything that happened it's all found on the National Weather Service so you can't do that on all of these other websites which you can do it through the National Weather Service because they have to archive that sort of stuff and so that's why I always tell folks use these authoritative weather sources I really I mean not that's the only source I really look at I mean wthr.com every once in a while because that's the Weather Channel I don't even look a techie weather weather bug you know I don't even have a smartphone so I don't have any of those apps but National Weather Service and they do have an app as well they're the ones that I look at every single day to you know to sees to see what our federal partners are doing and like I said ultimately going to be the ones pressing the buttons for the tornado warnings and hurricane warnings and all of that now the National Weather Service puts out all sorts of different types of forecasts it sometimes requires somebody to sit there all day and sift through all of the stuff that they put out for a certain location especially when the weather's getting bad it's hard to keep track of all of it and I even teach a course just for emergency managers on how to handle the National Weather Service and the amount of information that they put out and what's need to know and what's not so important and and all of that but nonetheless they have a ton of information they have all the information you need to know you just need to know how to read it and know where to find it but anyway I'll try to break it down here really quick for some of the important things that they've got you'll see a weather outlook they'll they'll push hazardous weather outlook for example it's just a forecast that's all it is if it's hazardous weather outlook is a forecast for hazardous weather it's generally not imminent it's generally just like a hey just say no you know be careful it's gonna be hot something like that right it could be for a day it could be for a season it could be shoot it could be for a year they have my climatological outlooks that are for a year you know even much longer than sometimes so all it is is a a forecast and there's a lot of times I'll just call it an outlook they have advisories advisories kind of like a step up from an outlook and they generally talk about hazardous nuisance weather for example frost advisories okay it's probably really not gonna affect too many people unless you're a farmer or something like that or you may need a couple extra minutes in the morning to scrape the frost ice off of your windshield or something like that it's probably not going to kill anybody it's not gonna call us really any widespread damage like I said Mamie unless you're a farmer or something like that you know heat there's heat advisories windchill advisories wind advisories so there's but they're just not not very severe they're just hey it's not normal it may be a nuisance but it's probably not gonna hurt or kill anybody or cause any extensive amount of damage so that's the first kind of line of defense that you'll see there as this advisory if you see an advisory yeah I pay attention to it but it's not as important as some of these other ones that we're gonna come come up with will see weather statements those are much like advisories a lot of times our downgrade from a weather warning usually they include hazardous weather phenomena for example here we got a rip current statement honestly I don't know why they call it a statement and they could just call it an advisory I see this a lot with like severe weather statements and and all of that or it's like oh you could just call it an advisory or maybe just keep it as a warning it could cause some life threats or property threats rev currents kill people okay so it's just it's good for you to know but it may not affect everybody so anyway it's out there it's much like an advisory it's worth reading it may be for the future it may be for right now but take a look at it statement then we have what we call a weather watch this and a weather warning get confused a lot from folks a watch indicates potential for dangerous weather it generally is a precursor to weather warnings meaning that some before warning you'll see a watch but generally if there's gonna be a widespread severe weather you're going to see a watch a weather watch before you see a weather warning so watch means that there's potential does not necessarily mean that the bad weather is occurring yet it just means that the atmosphere is prime to produce bad weather we're gonna watch for it that's what means weather watch a weather warning on the other hand is it's happening now it's imminent or it's occurring and it's likely to cause damage to property or people it could kill you it could hurt you it's dangerous you need to take cover and now do something about it now tornado warning take cover now severe thunderstorm warning take cover now so hurricane warnings and all of that hurricane force winds and say it's gonna create a lot of damage it could be deadly that is a warning it is imminent or it's already occurring hopefully we get it while it's imminent but sometimes we don't sometimes the way we find out it's happening is it's already happening okay and and it's just got to move with it we call it a weather warning and so yeah if you see a warning it's important pay attention to it do something about it right now alright so a lot of information in there if you need to review that information just go ahead and and move on back and go through it again if you have any questions you can always let me know and I'll be happy to elaborate a little bit more it's like I said it's a ton of information a lot of that stuff is I think I was already two years through college before I learned that level of of stuff so it's a lot of information that I wanted to give you but I didn't want to take two years of your life to give it to you so so there it is right here's maybe where we're kind of solidify some things it's just quite as see where you're at and we'll see we'll see how we do here right in the northern hemisphere what direction is a cold front usually bringing air from okay we're talking about northern hemisphere that's where you and I most of us are living if you're watching this although hey you never know well by web right but in the northern hemisphere what direction does a cold front usually bring air from well we think cold air cold air is from what direction in the Northern Hemisphere and it's from the north okay so we know North is gonna be in part of our answer okay now what direction do storms usually move from do they do they move from the north to the south did they move from the east to the west naw okay usually they're gonna move from the west to the east okay usually like I said it's gonna snow in the Rocky Mountains before it snows in the Midwest okay so we know north it's already part of this the answer the other thing is is it's moving cold fronts are going to move from west to east and so it probably can have more of a northwesterly component so which one of these answers most likely is gonna be the right one West to North Sound Brite east to South the cold front doesn't move from the east to the south south east to Southwest no that'd be more of a warm front because the warm air comes from the south and then east to west that's like 180 different degrees so not not super concerned about that one right now let's see what our right answer is right answer yeah right wesh2 north okay Northwestern he more or less and you can see the reasoning there right so cold air is generally found from the north however since low pressure systems generally move from west to east cold fronts typically come from west to north depending on the geography southerly winds are more character characteristic of warm fronts as warmer areas found to the south okay makes sense all right what air mass typically follows a warm front okay we already can knock two of these answers off right warm front is not cool air okay so come on dry that's out cool and moist that's out right so we know it's either C or D now remember I said about warm front warm fronts especially in the eastern half of the United States generally bring warm air from the Gulf of Mexico the Gulf of Mexico is dry or is it moist is it's muggy it's warm muggy swamp air okay so here I think D is going to be our best answer for the what air masses typically follows a warm front and sure enough there it is cool and dry air masses generally following a cold front cool and moist air mass is generally an occluded front or maybe a stationary front and a warm and dry air mass is going to be behind a dry line what weather instrument is best for viewing clouds at nighttime okay this takes us back to the weather instruments that we use okay radar and we use radar at nighttime yes absolutely what is radar look at though radar looks at precipitation not necessarily clouds okay you can have a overcast sky completely clouded up but if it's not raining the radar is not really gonna notice it okay so radar is out an anemometer and anemometer is a wind instrument it's what we use to measure wind speed and wind direction infrared satellite ok satellite can be used depending on which mode we're looking at from the satellite right a visible satellite can't be used at night time because it's just like using your two eyes to look at something at nighttime you're not gonna see it very well okay but an infrared satellite is heat-seeking so it essentially looks at the temperature of things right everything emits some sort of temperature day or night so that's why infrared satellite can look at clouds at nighttime so I think that's the right answer night-vision goggles you can sometimes it depends what the illumination is the moonlight but in complete darkness night-vision goggle still aren't going to work so we're going to have to go with infrared satellite here for our best answer and sure enough that's the correct answer all right which weather alert means imminent or occurring a weather watch or weather warning a weather advisory or a weather outlook okay weather watch remember we're just watching for severe weather it doesn't necessarily mean it's occurring and it just means that it has a potential for occurring okay so that's it's not a watch watch as always accompanied with the word potential okay weather warning yeah okay that's the right answer but I'm gonna go over these other two okay weather advisory okay weather advisory it could mean that is imminent occurring it could mean it may occur here in a little while but it's it's more nuisance weather okay it's it's like I said it could mean it's happening now it could mean us happening later weather outlook that's just a forecast could be happening now it could be happening later again weather warning if you hear that warning it is imminent or it's occurring if you hear watch that just means hey heads up we're gonna be watching for this weather makes sense okay weather warning is going to be the correct answer there remember just tornado warning it's imminent or it's a current take cover now lastly what direction does air flow around low pressure in the northern hemisphere okay this one this one was a tough one in college for me right it took a little while to figure this one out because we use the term called anti cyclonic and cyclonic and all of this and and that just confusing let's just talk in the way that the clock spins okay air flows around high pressure in a clockwise manner and low pressure and it caught a counter clockwise manner the easiest way for me to remember this was if you look at a hurricane and you see a hurricane hurricane just a low-pressure system it's a little bit different than like a winter storm low-pressure system but it's a low pressure system nonetheless in hurricanes you think of a cyclone which way it which way is turning it's if you've ever watched a hurricane and long enough on the TV or something you'll know which is going to be turning in a counterclockwise position okay hurricane the low-pressure system just like any other low-pressure system in the northern hemisphere it's going to turn counterclockwise okay high pressure is going to be clockwise yeah north to south not necessarily sometimes low pressure does move from north to south and sometimes it moves from south to north but that's not really a direction of flow around of the low-pressure it just might be the way that's a low pressure is moving but it doesn't mean necessarily the air flow around it the correct answer here is cyclonic or another word for that is counterclockwise and here you go here's a map I had this earlier in the slide deck you can see the air flowing counterclockwise around the low-pressure clockwise around the high-pressure ok well that about sums it up I hope you learned something here if you need to rewind watch it again if you need to email me send me a question whatever I'd be happy to answer any of your questions or elaborate on thinking maybe a little bit different to help you out this is a lot of information but I hope you enjoy this course there's a lot more to come depending on which course you're taking but it's all gonna build upon this sort of information right here so I strongly suggest you get a good grip of what's going on and these slides here and there's only like 35 of them or so it's not that many slides but it's a ton of information get a good grip on it so that as you progress through your whatever whichever course you're taking that you know how to build upon this one it's gonna be a little more difficult in the and and the following course slideshows if you don't understand this one you know at least at least a good bit and I'll reiterate it as we as we come up with it but this is gonna be your foundational understanding of how weather works again it's been great hanging with you thank you so much for your support and listening to me talk for the past hour like I said I'm here for you I want you to learn this stuff and I'm excited for for you as we progress further down this path thanks again [Music]