Oak before Ash
We’ll only have a splash
Ash before Oak
We’re in for a soak.”
Although weather forecasting involves relatively new technology, nature itself gives many hints at what sort of weather to expect. While not entirely reliable, terrestrial life responds to weather changes and it’s possible to become familiar with how wildlife behavior and the growth of plants and trees can be linked to weather patterns.
One sign of an oncoming thunderstorm is increased insect activity, which includes the return of bees to their hives. Birds and bats tend to fly lower than normal while the volume of croaking frogs increases. Flowers open and close. This is all in response to changes in air pressure and humidity.
In the hours leading up to severe weather, warm rising air carries insects high above the ground, drawing birds higher in search of food. Of course, a warm day in no way guarantees evening thunderstorms, but high-flying birds are a crude forecasting technique.
The migratory patterns of birds are a hallmark of the changing seasons. This time of year, we see Canadian geese returning from southern locales.
In the 18th century, English naturalist Gilbert White recorded the arrival of swallows for four decades. Their early arrival suggested a dry summer, and the early arrival of the waxwing in autumn portended a harsh winter. However, these migratory patterns are more suggestive of conditions where the birds left, rather than future conditions of where they arrive.
Another way to get an idea of the weather is to simply look around. The distance you can see is an approximate measure of how clear the air is. The higher the humidity, the lower the visibility and vice versa.
Phenology is the study of the progress of vegetation throughout the seasons. In 1735, Swedish naturalist Carolus Linnaeus was the first to put forth a method for recording leaf opening, flowering, fruiting, and falling as a climatological record.
Six generations in Norfolk, England, kept phenological records from 1736 through 1947. They recorded the first flowerings of the snowdrop, wood anemone, hawthorn, and turnip, the first leafings of 13 different types of trees, and ten dates concerning birds, butterflies, and frogs.
In a time before modern instruments for weather observation, phenological observations provided important data. These records show how the dates when native trees came into leaf varied by up to three months between the mildest and harshest springs.
Our own furry friends seem to have a sixth sense about the weather. Dogs are sensitive to changes in air pressure and some will respond by hiding or demonstrating changes in their normal behavior.
Groundhogs, on the other hand, are not so reliable. In North American folklore, the groundhog will emerge on February 2 and, if it sees its shadow, that foretells another six weeks of winter.
But the groundhog is only accurate as often as would be expected by chance. The National Oceanic and Atmospheric Association issued a statement this year debunking the tradition. “The groundhog has shown no talent for predicting the arrival of spring.”
March is the beginning of meteorological spring and ours might be five degrees below average temperatures, with a half-inch below average precipitation. Things should begin to heat up noticeably towards April, with the snow tapering off. We’ve has less white stuff this winter than in recent years—unless we get dumped on for a third consecutive April!