How to read
a weather map
What is a weather map?
The weather map is a chart showing the current climate while allowing us to predict future weather trends. It provides a simplified depiction of the current or predicted weather of an area. It displays a variety of meteorological features in a particular area at a particular moment in time. It uses a variety of symbols, which all have specific meanings, in order to indicate weather trends.
The most familiar map is the mean sea level analysis. This is compiled from hundreds of weather observations taken simultaneously. It is the map that is used daily on television and in the newspapers.
The dominant features of this map are the smooth, curving patterns of sea level isobars which show the central elements of our weather systems: highs, lows (including tropical cyclones) and cold fronts.
Isobars indicate lines of equal atmospheric pressure.
What do the symbols on the weather map mean?
Select a symbol
Select a symbol
Select a symbol
Severe Weather Warnings
Each warning has a different colour. Green indicates no severe warnings. Yellow means you should be aware of the weather. Orange indicates you should be prepared for severe weather while red means you will have to protect yourself from extremely severe conditions.
They also sometimes use symbols beside the warnings as follows:
- The movement of air from high to low pressures is measured on gradients. If the isobars are close together the difference between the areas of high and low pressure is greater and we have strong winds.
- When isobars form closed (but not always round) circles, the smallest circle in the center indicates a pressure center. This can be either a high-pressure or low pressure system. Air flows around these pressure gradients.
- Air moves around high pressure in a clockwise direction and low pressure in an anticlockwise direction, thus creating wind.
Fronts mark the boundaries between warmer air on one side and colder air on the other. If you are close to a front and it is moving towards you then you can expect a change in weather when the boundary of the front passes over you.
Cold front: This indicates potential torrential rain and high winds. It is illustrated by a blue line with blue triangles on one side. Whichever way the triangngles are pointing is the direction the cold front is moving.
Warm front: This often brings a gradual increase in rainfall which is then followed by prompt clearing and warming after it passes
Occluded front: This front usually brings drier air.
Stationary front: These types of fronts have long continuous rainy periods that linger for in one area for an extended period and move in waves.
Who relies on the weather forecast?
Select a symbol
- Although you can surf in all weathers (within reason) they need to check what the waves will be like.
- The harder the wind blows and the longer it blows for added to the distance it blows tells you what the waves will be like.
- Slight will affect the waves and surfers study weather maps in order to decide if they should hit the surf on any day.
Weather is a hugely important for farmers, and accurate weather forecasting makes their lives so much easier, including
- Tackling front (crops and livestock)
- Many seasonal plants require specific conditions to bloom and even the greenest fingered gardener can't save them if the weather goes awry.
- If long periods of rain are forecast it will also affect the insect population so there will be less bees around which affects the pollination of crops.
- Some plants specifically require good light and won't thrive in dull weather.
- There are numerous elements that affect sailors including wind direction, wind speed, the state of the sea and also thunderstorms.
- Getting caught out at sea in severe weather is extremely dangerous so getting all the advance information available is imperative for sailors.
- Accurate forecasting can help make decisions and prepare before going out to sea.
- Heading out in a boat during stormy weather leads to many lives lost every year.
- High winds can also make it more difficult to cast nets. Long spells of bad weather seriously affect a fisherman's ability to make a living.
- Bad weather can delay a landing & take-off.
- Knowing in advance that there is bad weather on the route means that a pilot can re-route to avoid it.
- In good weather they can take advantage of tailwinds to push the plane along, saving fuel.
OUTDOOR CONSTRUCTION WORKERS
- Rain makes work impossible for road paving crews, roofers and painters.
- High winds are extremely dangerous for anyone working on a height.
- Foremen will plan the construction schedule around the long term forecast so they can finish the job as efficiently and cost effectively as possible.
How does the weather map affect you?
Knowing what the weather is like makes it far easier to get dressed for the day
UV rays play an important role in conditions such as premature skin aging, eye damage and skin cancers.
Knowing what weather to expect can help you adequately prepare so you get the most enjoyment from your pursuits.
A big rainstorm in the middle of tiling a roof could at best destroy your hard work and at worst flood your home.
A big problem for those living beside canals heavy rainfall can also cause drains to overflow flooding, even those homes that are miles from the water.
Look out for severe weather warnings and if possible change any plans you may have accordingly.
How is the weather map prepared and who does it?
The weather map is prepared by meteorologists who are basically weather scientists. The weather map is a simple representation of the vast amount of information they process.