Television, radio, newspaper, or even Web site forecasters may not be as accurate as these simple, natural weather cues.
By Roger Meyer
February 2009
Do you want to know what tomorrow’s weather will bring? You could rely on newspaper forecasts, but they are often outdated by the time you read them. Or you can watch television, where the forecaster will tell you about the hottest and coldest spots in the United States that day and what year the local temperature records were set. Do you really want that information?
Then the forecaster might say, “We have about a 50 percent chance of light rain tomorrow.” Or maybe you’ll hear, “There’s a chance for high winds tomorrow.” Does this mean anything to you? Did the forecast help you much?
If you rely on weather radio broadcasts, or you’re a frequent visitor to weather Web sites, you may feel a bit more smug, thinking that with all of that information, the guess is more accurate. Meteorologists do use computers and a multitude of data to predict weather. And they claim they are 80 percent accurate. But this is a little misleading. Fair-weather predictions are easy and are factored into the 80 percent figure. During good weather, most of us can guess and be right 80 percent of the time. Most forecasts fail during bad weather, though, and that is when better predictions are critical. Unexpected weather changes can turn a trip into a miserable experience, or even a life-threatening one.
So, what can you do? Try forecasting the weather yourself. Perhaps you can do as well, or better, than that “50 percent chance of light rain.”
Rhymes To Remember
You probably know a few simple tips to predict the weather already. You might remember the rhyme: Red sky at night, sailors’ delight/Red sky at morning, sailors take warning. Why is this true? Low-angle sunlight refracts at sunrise or sunset. If this occurs during fair weather (high atmospheric pressure) with dry air, the sunlight appears reddish. If the redness occurs at sunset, the dry air is west of you and is approaching, in the normal flow of weather patterns in the Northern Hemisphere. If the redness occurs at sunrise, the dry air is east of you, and this increases the chances that the next air mass will be wet. So, a red sky at night is a better indicator of good weather ahead than a red sunrise is an indicator of bad weather.
Other rhymes also may be familiar: Ring around the moon, rain before noon/Ring around the sun, rain before night is done. High cirrus clouds cause rings around the moon or sun. These clouds appear hundreds of miles ahead of a warm front and its associated rain. So, cirrus clouds indicate no rain for a while, but it’s coming, probably in 12 to 18 hours. The bigger the ring, the thicker the cloud layer and the nearer the rain. Rings around the moon are more noticeable than rings around the sun.
If there’s heavy dew in the morning, it means the clear night skies allowed the temperature to drop low enough for moisture in the air to condense as dew. Clear skies mean no approaching warm front, and no rain for a while. If the overnight temperature drops only a little and there is no dew, it means that cloud cover and rain are probably approaching. The lack of dew occurs when the night temperature doesn’t drop far enough for dew to form. Remember this phrase: Grass is dry before morning/Look for rain before night.
Wildlife Forecasters
Animal and insect behavior often predicts weather. When ants walk in a straight line, rain is coming, and when they walk in circles, or randomly, it means good weather. Birds, insects, and most small animals are noisy when bad weather is 24 hours away, and become quieter as bad weather approaches. Flies are an exception. They become more troublesome as a storm approaches. Another exception are crickets. If they make a great deal of noise at night, the next day will be fair. If birds are taking dirt baths, it will probably rain within 12 hours.
Birds fluffing their feathers, feeding ravenously, or gathering in groups are other signs of bad weather. If birds feed in the rain, expect the rain to continue for a while. In a short storm, the birds will wait to feed. Spiderwebs absorb moisture and break easier in the high humidity associated with an approaching low-pressure area. If you see a spider spinning a web, it’s probably not going to rain for a while.
Birds fly high, clear blue sky/Birds fly low, rain we shall know. Good weather is associated with high atmospheric pressure. One theory as to why the bird rhyme was created is that air density decreases as a low-pressure area approaches. It’s harder for birds to fly in thin air, so their flights are lower and shorter than normal.
Robins build fragile nests. They roost to hold the nest together in approaching storms. If you see a robin hopping around during breeding season, expect fair weather. In some areas, deer tend to move downhill a day or two before a storm hits. If deer feed in early afternoon, expect bad weather within 24 hours.
Sounds And Scents Are Clues
If sounds seem louder or travel farther, rain is coming. Humid air, associated with incoming low-pressure areas, transfers sound better than the dry air of high-pressure systems.
If odors are stronger, it also indicates rain is on the way. Plants release more aromatic oils in the high humidity of approaching bad weather. Other odors are also more pronounced as bad weather approaches. Scents are weaker in high-pressure areas because they are squeezed tight to the source. With lower pressure, odors are released easier and we are more likely to notice them. We sometimes subconsciously observe this and say, “It smells like rain.” Our body odor becomes more apparent as a storm heads our way. Increased odor near urban sewers or drains also indicates approaching bad weather, because lower air pressure allows the scent to flow more freely.
It’s A Breeze
Wind is another weather indicator. Predicting the weather from the wind direction depends upon where you are. If you are in the eastern part of the United States or Canada and the wind is from the east or south, expect rain. Wind from the northeast may bring two or three days of rain starting in 24 hours. Westerly winds bring fair weather. Fair winds usually come from the southwest in the summer and the northwest in the winter.
Winds are calm ahead of a wide warm front, so if rain appears before the wind, expect a long rain. If the wind arrives first, it’s a narrow cold front and the precipitation will end soon. With low winds, expect warmer temperatures as the warm front approaches. Expect cooler weather with increasing winds as a cold front advances closer.
If the temperature increases during a rainstorm or snowstorm, expect the precipitation to continue. It’s because a warm front is passing and the precipitation extends on both sides of a warm front.
When you see the underside of tree leaves, rain is coming within 24 hours. Leaves grow normally with the prevailing fair-weather winds. Winds from other than the fair-weather direction blow the leaves differently, and they tend to flip over. So, the undersides of leaves appear when the wind shifts from the usual fair-weather direction.
If the wind is shifting in a counterclockwise direction (for example, shifting from west to southwest), expect poorer weather within 24 hours. If the shift is clockwise (for example, from south to southwest), expect the weather to improve.
Watch The Sky
Twinkling stars indicate strong upper-altitude winds, which are usually a warning that bad weather will arrive in two or three days. If stars appear bluer than normal, it’s also a sign that rain is coming. Humid air absorbs the red light from the stars, causing them to appear a slightly different color.
Check your campfire smoke. If it rises quickly, expect clear weather. If the smoke drifts, then settles lower, expect rain. The same is true of chimney smoke. Under high atmospheric pressure, the temperature decreases rapidly with height and allows the slowly cooling smoke to continue rising. In a low-pressure situation, the temperature changes less with altitude. Smoke quickly becomes the same temperature as the air and stops rising.
In general, people tend to feel poorly as humidity increases and bad weather approaches. If you experience more headaches, sleeplessness, or arthritic pain, bad weather could be approaching. Children and pets often misbehave more as a storm nears.
If the clouds look like fish scales (called a “mackerel” sky), expect a lasting rain in eight to 24 hours. These clouds appear in advance of warm fronts. A mackerel sky indicates that it will not rain for at least eight hours, which is why some people say a mackerel sky indicates no rain. That’s true, but for only eight to 24 hours. Then, it will rain.
You can’t accurately predict the weather more than two or three days ahead, but it helps to know that weather patterns tend to repeat on a five-to-seven-day cycle. This is why it sometimes seems to rain every weekend.
Try using these tips to predict the weather. Don’t rely on only one clue, as it could be an unusual event. But when several weather signs say the same thing, believe them. Any fewer than two clues and your prediction should be “50 percent chance of light rain, but it’s a little too early to tell for sure.”