So you are off on a trip away from civilization, but you forgot to take your NOAA Weather Radio. Do you have any way of making more than a guess about the forthcoming weather for the next half day or so? Sure, you can.
Stand out in the open with your back to the wind. Raise your left arm to a horizontal position and then move your arm slightly forward. Your left hand is now pointing toward low pressure.
Why is that relationship so? Check it out by using the knowledge you have learned in the DataStreme course, while keeping in mind that you are in the Northern Hemisphere. On a piece of paper, draw a couple of concentric isobars around an "L". Draw some curved arrows showing the winds circulating counterclockwise around the low pressure center. Imagine yourself on the map you just drew (but not at the "L") with the wind to your back and your left arm extended. Your arm would be pointing toward the "L". Buys-Ballot, a Dutch meteorologist, noticed this rule on weather maps in the mid 1800's. If you stand with the wind at your back, the low pressure center will be to your left.
To make a weather prediction, you also have to recall that weather systems tend to travel from west to east. So, if you are facing north while the wind is to your back, the lower pressure is to your left (to the west of you). And, the low would be coming toward you. As you know, low pressure approaching you often means stormy weather is on the way. That would be your forecast. Conversely, if you observe a northerly wind, the low would be to your east, and you could forecast that the weather should improve as the low pulls away and the high pressure moves toward you.
So how can we make our own wind observations, and what can we learn from our observations? If you are curious, refer to the optional Supplemental Summary Information for Tuesday.
To be submitted on the lines for Tuesday on the Study Guide, Part B, Applications, Week 8 Chapter Progress Response Form, under section B. Daily Summary.