ANIMAL WEATHER FORECASTERS

Wednesday, February 07, 2007

Did you happen to see a groundhog on February 2nd? Whether you did or didn’t, we can assume that winter will continue, until it is finished.

Old beliefs die hard. Some put a lot of faith in the size of the band around the woolly bear caterpillar. People study it with great conviction and then determine the severity of the next three months ahead. Fascinating stuff, I suppose. But not really very soothsaying. Certainly the size of the light brown band around the middle of these woolly bear caterpillars is more a reflection of what has already affected the insect to cause it to be that way, than it is a portent of weather.

But knowledge of weather predicting can go the other way too. Some people don’t even have a basic understanding of weather clues at all. I am reminded of the camper at Sandbanks who, during an evening program on a bright, starry, calm night, asked if it would be raining within the next hour of the program. This person had absolutely no concept of any clues that might serve to predict the weather conditions over the next several days or months, never mind the next hour. Clouds, or the lack of them, meant little, and there was no experience with what the heavy dew that morning meant, he didn’t look for a halo around the moon, or check the colour of the sunset.

There is really nothing occult or supernatural about checking for these things. There are explanations as to why they occur, and they can be useful in predicting weather. The bulbous, formidable mammatus clouds we saw in the sky a few summers ago after the passing of a band of severe thunderstorms was a clear indication of turbulent weather in the area. Ask the residents of Barrie who saw the same formation in 1985 when a tornado carved a path through a residential area there.

"Red sky at night, sailors delight. Red sky at morning, sailors take warning." Normally our weather systems move from west to east. Dust in the atmosphere causes brilliant sunsets when clouds are high and dust is returning to the atmosphere. If the sky is red in the morning, clouds have not yet arrived, there is still sufficient dust in the air, but rain is on the way. Moon halos are formed when ice crystals in fine cirrus clouds refract the moon’s light. These upper atmosphere clouds form when a warm front approaches cooler ground air. This collision usually brings stormy weather, generally within 24 hours. How about the number of stars inside the halo indicating the number of days before rain arrives? Well, that may be pushing it a bit, although it has been a popular belief for many years.

But despite the fables about groundhogs and woolly bears, we shouldn’t totally discount the actions of animals when predicting weather. But there is always a reason. We once had a dog who could predict with uncanny accuracy with her behaviour if there was a thunderstorm in the offing, long before there was even any thunder. This behaviour seems to be characteristic of many domestic animals as well as wild ones and appears to be triggered by a drop in atmospheric pressure. Some are obviously more sensitive to these changes than others. Similarly frogs croaking incessantly is a good sign that rain is near, because they cannot tolerate low humidity and usually remain under water to cut down on evaporation of their skin’s moisture when days or evenings are dry. But when the humidity rises as a storm approaches, out they come croaking away in collective happiness. Even some of us with injuries can predict changes in weather with a drop in atmospheric pressure as sensitive tooth roots, sinuses, old injuries and aching backs start to kick up.

Swallows flying low over the fields indicating rain is simple to explain when one realizes that swallows are in pursuit of insects, which themselves fly low over fields as the pressure drops. The swallows are just following their food source.

So how about this lore regarding the cricket and the number of chirps per minute determining the temperature. Well, some things you can’t explain, but if you count the number of chirps within a 15-second interval and add 37, about 75% of the time you will arrive at the present temperature within a few degrees.

So, some animals can tell us quite a bit about the weather ahead, just by their actions. Mostly though these days I just check the Doppler radar on my home computer and download the weather from the Internet. Then I have someone to blame if weather predictions turn out to be incorrect.