Reading a Weather Map

Good morning, everybody. I'm meteorologist Ryan Davidson. I'm actually Elizabeth's mom's cousin, and I work here at the Weather Channel. And I hear you guys are learning about weather, so we're going to talk a couple of things about weather systems in fronts and kind of how those all come together to make weather and then we'll talk a little bit about your forecast.

So first off, we're going to talk about understanding what goes on in a weather map. So first we've got cold air and as it pushes further to the south along the leading edge of where that cold air is advancing is where we would set up a cold front. That's going to be this blue line here with all these triangles, and they point in the direction the cold front is moving.

Now the other side we have a warm front. When you have a mass of warm air moving northward, or in any direction, the leading edge of that warm air mass. This where we draw this warm front which is going to be the little red line with the half circles. The best way to remember it is they're like little half Suns, so they're always denoting warmer air. You kind of work it out that way where Sun warmth, warm front, right like that. So, that's how we denote where a warm front lays.

Now, when we start moving and adding in things like pressure systems. We have a low-pressure system right here. Air around the low-pressure system moves counterclockwise and inward, so when we start putting those air masses around that area of low pressure, we begin to see just a few things happening here. The warm air surging northward, that's where the warm front is. The cold front surging southward, that's where we line up that cold front.

And then we zoom in closer, where we get all the precipitation. What's going to happen here is, you've got this air coming down from the north and this air kind of going towards the north and east. What happens is this piles up as it gets close to this warm air mass and it starts to lift. So where are these meet, all that wind meets, we call that convergence; the meeting of air. When it happens, it starts to go, it has nowhere to go, so it has to go up and once that starts going up that's where we start to get clouds and rain. And usually along the cold frontal side of a storm is where we'll see things like thunderstorms. But on the warm frontal side, over to the north, that's where we'll start to see just broad areas of rain and showers and cloudiness, and that comes through all the weather gets a little bit cooler.

Now high-pressure a little bit different. High-pressure systems air goes clockwise and outwards from an area of high-pressure. So why don't we ever see any rain or anything near an area of high pressure? When you have all of this air moving outwards, it's actually like if you were going to turn the hose right on the ground what happens is that water goes down and it spreads out. You don't have any lift, so you don't have anything to create that up flow of moisture to create any precipitation. So usually when we talk about high pressure, we talk about nice weather.

But let's take a look at what your forecast is looking like as we go through the next couple of days. We're going to be looking at a little bit of rain. We've got a couple of fronts to the south here is our warm fronts either red with the half-circles that's going to come northward. We're going to see a little bit of rain in eastern and central North Carolina as these low-pressure systems and their cold fronts and warm fronts move along the eastern seaboard. Then by Wednesday, we'll see maybe a little bit of rain in Raleigh, but it quickly moves out, and we start to see some high-pressure move in. How do we know? Well, we don't see any weather going on here by Thursday, and that'll stay the same even as we head into Friday. Things kind of clear out, but the next weather system comes on in we start to see some rain heading in portions of western Tennessee and portions of Mississippi. So here's what comes up for Raleigh over the next five days. We've got rain on Wednesday and a little bit cooler; notice, as we get that cold front to come through it, brings that rain, 48 degrees. Then we warm up and high pressure moves in we get sunny conditions and our temperatures kind of get back into the middle 50s, and we get really nice by Sunday for the temperature of 63 degrees.