Basics on Weather Forecasting

When a disaster or a catastrophe happens, one of the things that is likely to happen Is a loss of internet and news availability. Because of this, it can be useful to know the basics of determining what the weather will be like in coming days. Things can change so quickly during the day and it can seem chaotic, but there are usually ways to know ahead of time at least some idea of what to expect. 

Weather refers to the changes and happenings in the atmosphere, which includes things such as temperature, wind, rain, storms, and more. Many simple methods can be learned that can help to predict the weather without extensive technology.

The sun is the primary factor in weather changes. Areas near the equator receive more of the sun’s energy than the areas around the poles, which is recognizable by the temperature differences between those areas. Different biomes handle the sun’s energy in different ways, as evidenced by the difference between the rainforest and the desert that are near the same longitude. This is also affected by the earth’s tilt. 

Air pressure or atmospheric pressure affects the wind, as air tends to move from high pressure areas to those of low pressure. The bigger the pressure difference, the faster the air will move. 

Another factor is humidity. How damp the air is – how much water vapor it holds – determines the level of precipitation: rain, snow, hail, etc. It also determines how many clouds will be in the air at any moment. The type of clouds in the sky are also clues to what the weather will be like. 

Altitude also has some bearing on the weather. Temperatures tend to be cooler at higher altitudes as the air is thinner. 

Figuring out what the weather will be like ahead of time has grown more precise over time. Twenty years ago, one day was about as accurate as the meteorologists usually were able to be, but now the forecasts tend to be accurate up to five days ahead, because more has been learned about how the weather works and what to watch to know what to expect. 

Predictions are dependent on observation, including temperature, humidity, pressure, and precipitation. However, weather does tend to follow patterns, so a good preliminary step would be to study the weather maps for the area where one plans to be. Knowing the historical weather can be of great assistance in predicting future weather. 

There are several techniques often used for forecasting, including persistence, trend, and analogue. Persistence assumes that the weather is likely to be the same. It can be accurate for a little while, but stops being very reliable by a full day. Trend watches what is happening and sees what is coming within a few minutes to a couple hours. It tends to be less accurate after a few hours. Analogue looks at what has happened previously and assumes patterns will continue. This may not be as accurate as other options but will often see similar patterns. 

Some old sayings about weather are based in truth. Knowing them can assist in predicting the weather.

  • “A ring around the sun or moon means rain is coming very soon.” 

This is true because the humidity between the observer and the moon causes the appearance of a halo due to reflection and refraction.

  • “Red sky at night, sailor’s delight. Red sky in the morning, sailors take warning!”

Sometimes it is “shepherds” rather than “sailors” but it is rooted in reality. When the sky is red at night, it usually is due to clouds being to the east, which is generally already past (the Jetstream goes from west to east, so most weather also follows that path, though there are exceptions). Therefore, it is likely to be clear the next day. However, when the sky is red in the morning, the clouds are to the west, which means they are still on their way. 

  • “The sharper the blast, the sooner ‘tis past.” 

Another way of saying this is, “the quicker it comes, the quicker it goes.” When rain comes up suddenly, it is usually strong and fast and moves on as quickly as it came. When it moves in slowly, it is moving slowly and may stay a while.

  • “The higher the clouds, the finer the weather.” “When clouds appear like towers, the earth is refreshed by frequent showers.”

When clouds are wispy and high, the weather will be nice. When the clouds are tall and built up, it is more likely to rain and when these clouds turn dark, it will probably storm. 

People have been heard to say, “It smells like rain.” This is usually a fairly accurate way to predict a coming shower. When flowers are easier to smell and the smell is stronger, this also usually heralds rain. 

Air pressure can be trickier to figure out unless a barometer is available. Without one, it can be determined by watching the smoke from the campfire. If it rises directly up, then pressure is high; if it sinks and swirls, pressure is low, and rain is likely.

The direction of the wind tells a lot. Look at the speed and direction; the wind is usually named after the direction from which it is coming. The terrain in that direction will have some bearing on the results of the wind. When winds come from the opposite direction than usual, storms are more likely. The speed can be estimated by how cool it feels – stronger winds tend to feel cooler. 

Wildlife can also indicate the weather by how they behave. Birds are aware of air pressure, and geese, for instance, tend to fly higher when the atmospheric pressure is higher and lower when it is lower. Snakes often leave their nests in cooler temperatures when bad weather is coming (they are often in the sun when it is warm). Cows will lie down if a storm is coming. 

Resources

Product
Visual
Where to Buy
National Geographic Pocket Guide to the Weather of North America
Storm Cloud Barometer
Kid’s Weatherpedia
Field Guide to the Weather

 

National Geographic Pocket Guide to the Weather of North America

Learn from National Geographic’s 144 topics with photographs and information. 

Storm Cloud Barometer

A simple barometer that can sit anywhere can help to know what to expect.

Kid’s Weatherpedia

Though intended for children, even adults can enjoy this informational book and learn how to read the weather. 

Field Guide to the Weather

Identification information for clouds, storms, and other weather. Written by a professional meteorologist, this field guide is a handy reference for a variety of topics related to weather.