Do you always find the various symbols on your smartphone’s weather app or TV confusing? Would you like to update yourself with all the necessary information about different types of weather symbols, along with their meanings and illustrations? If so, this article provides you with a detailed list of weather symbols and their meanings.
What Are Weather Symbols?
Weather symbols are the graphical representations of various atmospheric conditions commonly used in meteorological forecasts to show current and future weather conditions. Although these symbols are commonly used alongside a synoptic weather map, they can also be shown separately. Weather symbols are placed on the synoptic map along with the position of weather stations gathering information about the weather and details of different weather elements.
The location of each meteorological station is indicated by a small circle, while its weather report is plotted in and around the circle. Other important elements, such as temperature and pressure, are keyed in as plain figures. Others, like the amount of rain, snow, cloud, and fog, are represented as universally approved symbols.
For instance, cloud cover at a certain time is shown by filling in some parts of the circle. The larger the fill, the bigger the cloud cover, which is measured in eighths or oktas. Wind direction is characterized by an arrow showing where the wind is coming. The speed of the wind is shown by “feathers” on the wind arrow. A short feather indicates 5 knots, while a larger one shows 10 knots. You will also find a long and short feather that indicates 15 knots.
Temperature is measured in degrees Celsius to the nearest whole degree. At every station, pressure is standardized to sea-level pressure, which is often measured in millibars. Since the pressure is almost always between 950 and 1050 millibars, sometimes the hundreds figure for the pressure is left out with the assumption that it is understood. For instance, a pressure of 987.8 millibars can be shown as 878, while that of 1014.3 millibars can be written as 143.
Different Weather Symbols and Their Meanings
1. Cloud Cover
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Clouds are classified into different categories, based on their appearance and the altitude at which they are located. Cloud cover is the percentage of sections of the sky which is covered by clouds, further a direct impact on the local weather. Cumulus clouds appear as semicircles, while cumulonimbus is a semicircle with a trapezium on top.
Altocumulus cloud appears as two semicircles hinged to each other, while the cirrus clouds are drawn as lines with curves. Altostratus is drawn in the form of an acute angle. So, the clouds in weather symbols look more or less the same as they appear in the atmosphere.
Cloud cover is presented in the form of a circle that can be divided into equal portions. Some of these parts may be colored, depending on the amount of the cloud cover. If the sky is fully covered, it is presented as a clack circle, while specifically darkened quadrants show the sky cover in the form of segments, such as two-tenths, five-tenths, six-tenths, and so on. A no-clouds symbol is shown as a completely colorless or white circle. Sometimes, both the sky cover and cloud type symbols are shown together to offer more data from the studied areas.
2. Weather Fronts
Also referred to as front-line borders, weather fronts show the line of separation between hot and cold air masses present in either high or low-pressure regions. Letter ‘H’ in blue signifies a high-pressure area, while the letter ‘L’ in red represents a low-pressure area. A high-pressure area is caused by atmospheric air under increasing pressure which drops towards the land surface, while a low-pressure area is characterized by reducing the pressure of air that goes upwards.
A cold front is characterized by a blue-colored curved line with triangular points, which show the direction of the wind. On the other hand, a warm front is characterized by curved red-colored lines with rounded or semi-circular points that lean towards the direction of the wind. When the two lines meet in particular areas, they create static front – boundaries that don’t indicate much movement and are characterized by interchanging points of the two front types.
These boundaries can move forward or backward every day, with each point showing more or less similar strength. When a cold front overpowers a hot one, it is characterized by a purple line, with both curved and triangular points leaning in the same direction. This helps you to understand the approach of a storm.
3. Rain
Image source: weatheronline.co.uk
Rain symbols are very common on many modern gadgets. Two dots that are close to each other show average rainfall, while four dots show heavy rainfall. Extremely heavy showers and snowfall are characterized by triangular lines.
Fog or mist is characterized by three to four straight horizontal lines. Most triangular symbols signify violent rain, and if they are accompanied by other extensions, they show showers with snow and hail, or rain with snow occurrence. These signs vary in appearance and positioning, based on the setup in which they are observed.
The most conventional triangular symbols are readily available on most of the latest devices. Ins some cases, the four dots indicating heavy rainfall might be located close to each other, or even in a closed-loop format. Another notable characteristic of triangular symbols is that they can be combined with several other common symbols that represent weather.
For instance, if the fog symbol of three horizontal parallel lines is shown in front of the sun weather symbol, it can be interpreted to mean partially foggy or fog with mild sunlight. If sun and rain droplets are presented together, it means that rain is accompanied by low-intensity sunlight.
4. Wind Speed and Direction
Image source: ww2010.atmos.uiuc.edu
Wind speed and direction signs are the simplest weather symbols, especially since they are represented as lines drawn with long or short extensions known as barbs. The least powerful ones are characterized by a circular symbol and may have a speed of between 0 – 5 knots.
A short extension indicates the presence of an additional velocity of 5 knots, while a long extension shows an additional velocity of 10 knots. A triangular barb shows a speed of 50 knots.
If the end of the line is open, it shows the direction towards which the currents are flowing. A knot is a measuring unit of wind current speed, and 1 knot represents about 1.15 miles per hour. Barbs are always drawn progressively, with the ones that have the highest value appearing near the end. The ones with the lowest value appear on the middle part of the line.
If a line comes from the south straight upwards, it shows that the wind is flowing in the northern direction. If this wind current is indicated with two short and long extensions each, accompanied by a triangular point, it means that the wind is blowing at a speed of 80 knots. And if two lines are present, it shows two separate currents are passing through an area with different intensities.
5. Sunny Conditions
A sunny symbol is the most familiar of all the weather signs. It indicates sunny conditions and clear skies. This symbol is also pretty straightforward and hardly used in any other way than to show exactly these weather conditions.
6. Thunderstorm
This symbol depicts thunderstorms with strong winds, lightning, and heavy rain. It is one of the weather symbols that you should never ignore, mainly because of the dangerous weather conditions that go with this weather event.
7. Hail Storm
This symbol shows a hail (frozen water) storm. Hail is often associated with thunderstorms because of the similar weather conditions that generate both.
8. Light Snow Shower
This symbol means that a light shower of snow (a bunch of ice rocks) is likely to fall. This symbol should bother you so much, especially if you live in an area familiar with regular snowfall.
But if it happens in an area that rarely experiences snowfall, you should be concerned, especially because the weather event could be accompanied by serious conditions such as a drastic drop in temperature and slippery roads.
9. Heavy Snow Shower
This symbol indicates that a heavy shower of snow is about to fall. Since this weather event is normally accompanied by potentially dangerous conditions, you should take care.
10. Mist
Mist is just a high concentration of micro water droplets in the air near the ground’s surface. The mist symbol indicates damp weather conditions with adjustable degrees of low visibility. You should take care, especially if you are driving.
11. Drizzle
The drizzle symbol means that a very fine form of rain is about to occur. Although the water droplets are almost unnoticeable, you shouldn’t ignore this sign because a drizzle can be very persistent, leaving you thoroughly drenched over time.
12. Sleet
This weather symbol usually indicates a combination of rain and snow and even small ice pellets.
13. Tropical Storm
This weather symbol predicts a tropical storm and is not often used in a weather forecast. But when you see it, you should pay serious attention because a tropical storm is destructive enough on its own. Also, a tropical storm can turn into a hurricane very quickly. It’s needless to emphasize how powerful and damaging a hurricane can be.