Introductory Meteorology

Lesson 6. Surface Patterns of Pressure and Wind


wind power
Modern wind turbines are huge!
Credit: David Babb

When it comes to casual discussions about the weather, wind is like the forgotten child. Sure, there's talk about the wind when there's some damage caused by a severe thunderstorm or a hurricane, but, honestly, when was the last time that you overheard, "I wonder if it's going to be windy this weekend?" Comments like, "I wonder if it's going to rain on Saturday?" or, "Did you hear it's going to be in the 70's tomorrow?" are much more common. Never do we discuss the latest atmospheric pressure trend or the wind forecast (except perhaps if you are, or are friends with, a sailor. They're always interested in the winds!).

However, let us not disparage the wind and the pattern of surface pressure that drives it. In this chapter, we will learn about how air circulates around high and low pressure systems. Did you know that the wind doesn't just blow from higher pressure to lower pressure? There are several different forces that work together, including the pressure gradient force, the Coriolis force, and even friction. Speaking of the Coriolis force, it's one of the most misunderstood concepts in the population's general understanding of the weather. Check out this YouTube videoYikes! Pretty much everything this guy says is total garbage, but I would wager that a majority of folks would find this explanation plausible. Hopefully, by the end of this chapter, you will be able to point out the fallacies of this gentleman's explanation.

Another topic that we will revisit in this chapter is fronts. We have already covered the temperature patterns associated with different kinds of surface fronts, and, in this lesson, you will learn about pressure and wind changes across a front as well. At the end of this chapter, you will have enough knowledge to be able to interpret basic surface maps like this one. Skills such as identifying centers of high and low pressure, fronts, spotting troughs and ridges, figuring out wind direction and relative speed, are all within your grasp. Combine these skills with your understanding of satellite and radar imagery, radiation, temperature, and atmospheric moisture, and you've got a pretty complete set of useful weather analysis skills. Let's get started!