Forecasting Weather From Nature |
 Dave Thurlow, Host |
In response to a bit of folklore from the farmyard, I asked a dairy farmer why cows lie down before it rains. "Cause they're tired?" she said. Well that could be all there is to it. Seems to me that cows or birds or trees are physically sensitive to the atmosphere and sometimes do react to its changing properties. Hi, I'm Dave Thurlow from the Mount Washington Observatory and this is The Weather Notebook.
People aren't as naturally sensitive to atmospheric changes so we let weather instruments do the reacting for us and in turn react to them. If the barometer falls, we run for cover. But, if for some strange reason your stuck out there without a barometer, or even a sling psychrometer (heaven forbid) then you might want to take a look at these signs of nature sensing weather changes as they happen.
In the summer, swallows will fly close to the ground before a rain. Swallows eat bugs, and the bugs fly lower in the lighter air that precedes a storm. Leaves on hardwood trees also predict rain. The increase in humidity before a storm will soften the leaf stems so that the leave shakes around in the wind making the pale green underside of the leaf more visible. On a clear fall evening you can forecast the overnight low temperature by counting the chirps of a cricket because crickets run out of chirping energy as the night air cools. In the winter, very dry air will result in a loud snapping and popping of trees. This assures at least one day of fine weather, because cold and dry air is heavy and slow to leave. Remember, all these forecasting signs are just nature reacting to subtle atmospheric changes that take place before the arrival of the not-so-subtle changes that we call weather.
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