Transcription
Hello everyone and welcome to weather 101. I am meteorologist Ken Batis. Thank you for joining me today and being a part of the opening to what I hope is a successful series and informing everyone about meteorology in terms that they can understand.
Today we'll be talking about mid latitude cyclones. You may hear this described on the news as a storm system, but the technical term is mid latitude cyclone. We're talking about this because a mid latitude cyclone is going to bring a winter storm to the middle west and severe weather to the south. So, let's get into it.
Mid latitude cyclone start with an area of low pressure that's represented by the L right there. The air around a low pressure center spans counterclockwise. When you see how the different masses of air flows around it, it will all make sense.
Coming in from the northwest is a cold, dry air. This is the air that pushes in a cold front down from the northwest. Coming in from the south is warm, moist, unstable air. This is the air that's pushing a warm front northward. And finally, there is a flow of cool air moving in from the east to the west, and that is our cool air flow.
So now that we know about the makeup of of the different air masses and how they flow, let's talk about how this ties into precipitation. Let's bring back the air of the area of low pressure and the two fronts. There they are right there. Now we're going to see how the areas of precipitation ties into the different flows of air.
Now we're going to bring up the precipitation area right here. Notice how it looks like a comma head. You'll see that reference made a lot to mid latice and cyclones and news outlets and other media outlets.
Along the cold front is where we will find our convection. This is thunderstorms and in some scenarios severe weather. You most you'll most likely see those as like squal lines. You may hear it no you may hear it called like that. To the south of the warm front we have our rain. And just to the north of the warmfront we have our rain snow mix. And further north we have our snow. And also to the west to the west of the area low pressure we have more snow.
Now, let's tie in the different air masses. We have our cold, dry air mass coming in from the northwest. And you see how there's no precipitation around that because, of course, it is dry. We have warm, moist air coming in from the south. Typically, this is air pulled in from the Gulf of Mexico. You can imagine how the warm moist air gets pulled into the area of low pressure and wrapped around the area of low pressure and counterclockwise like that. And then we have our cool air flow that's moving in from the east to the west. And notice how it coincides with the rain snow mix.
Now let's talk about the severe weather ingredients because they are all present. They are first moisture, second is lift, the third is instability and the fourth is shear. The moisture instability is coming from the warm moist air flow. The lift is provided from the coldront. Think of it as a rank that air can rise up and open. The shear is from the deferring wind directions from the cold dry air and the warm moist air. And this is why the storm prediction center has a slight risk severe weather for tomorrow along the frontal boundary. And also an interesting tidbit is notice how the outlook has the same shape like the comma head and the outlook for tomorrow.
Now this is a real world example for the next couple of days. This is from the GFS model. We use this to help us forecast. I'll let it run through a few loops so you can see how it develops and moves across the country. Keep an eye out for the comma head shape as it moves over the Midwest. And I'll show you how this all ties together on the next slide.
Okay. So, I chose an image where you can clearly see the comet head. Now, let's add the features of a mid latitude cyclone that you should be familiar with by now. We have our area of low pressure, the cold front, and the warm front. You should be able to tell what kind of precipitation is falling in which location based on the previous image I showed at the beginning of the video.
Also, notice the wind barbs. Oops. Um, sorry about that. Notice the wind barbs. They are they show which direction the winds are flowing and how fast they're flowing. Notice the winds behind the front are northwesterly. Notice how there is a southerntherly flow of moisture coming in from the Gulf of Mexico. And remember our cool dry our cool air is moving up from the east to the west. And notice how this it's all wrapping around this area low pressure in a counterclockwise direction.
So thank you for joining weather 101 today. For more on this, stay tuned to weather infinity. I haven't decided how often I'll do these videos yet, but you can find discussions daily on www.weatherinfiniti.comdiscussion. Thanks again for joining. This is meteorologist Kevin Vis.