Meteorology and Weather Forecasting By: Brandon MacKinnon & Ben Forsythe

What is a Meteorologist? Meteorology is the scientific study of the atmosphere. Meteorologist's are scientists who study meteorology. Meteorologists work at weather-forecasting. You can see this almost everyday, even on The News. Weather-forecasting is the appliance of science and technology to predict the state of the atmosphere for a future time, and a certain location.

How Meteorologists create a forecast Meteorologist combine data recorded hourly from many weather stations to create to the date weather maps. The most complex weather maps are only used by meteorologists themselves because they use a more array of symbols to communicate many more atmospheric conditions. Meteorologists use tools like weather maps, and sensing technology. They observe trends and patterns and mimic both short range, and long range forecasts (Short Range = 48 hours, Long Range = 3-7 Days).

Short Range Forecast Meteorologists' use a variety of techniques, the simplest is called persistent forecasting, which basically means that they presume the current weather conditions/patterns will follow into the future. Because atmospheric conditions are always changing, persistent forecasting is the most accurate, up to a few hours. Another technique is called “now-casting”, which forecasts weather conditions up to six hours. Now-casting relies on remote sensing technology, and is especially helpful in predicting storm movement.

An actual picture of a storm An infrared picture of a storm

Various weather conditions

Long Range Forecasts Long Range forecasts rely on computer based statistical analysis on past weather data, and computer models of atmospheric circulation and behavior. Long Range forecasting is less reliable than Short Range forecasting. This is because computer models have to make certain assumptions on how the atmosphere will behave. These assumptions may be correct in some situations, and less in others. The atmosphere is still one of the most unpredictable systems on earth, and do to it's unpredictability several different computer models are typically used to produce long range forecast's, and the average forecast of each computer is used.

Long Range Forecasts Long Range forecast's are good at predicting large scale weather patterns, compared to small scale patterns. For example, it may be able to predict colder winter's in the east of Canada, but it would be hard to predict the type of winter that Sydney, or Margaree would have (More specific area). This is because surface factors such as local terrain, and wind patterns, often affect local weather is ways that models can't predict.

Weather Map All components that make up weather are recorded at regular intervals, the data is then analyzed to identify and predict weather conditions in a certain area. To ensure that information is presented clearly and concisely as possible meteorologists use a set of symbols for weather conditions.

Weather Symbols

How forecasting is done Meteorologists use multiple factors to create a weather forecast. Some of these factors include: Cyclones, Anti-Cyclones, Cold Fronts, Warm Fronts, Stationary Fronts, Occluded Fronts, and Dry Lines.

Cyclones An area of low pressure, in which the wind flows counterclockwise to the northern hemisphere. They are known as a low pressure center. The rising motion may produce clouds, and/or precipitation.

Anti-Cyclones This is the opposite of a cyclone. It is a high pressure center, where the pressure has been measured to be the highest relative to its surroundings. It results in northerly winds, and colder temperature.

Warm Fronts Stationary Fronts Cold Fronts A cold front is a transition zone where a cold air mass is replacing a warm one. Warm Fronts A warm front is a transition zone where a warm air mass is replacing a cold one. Stationary Fronts A stationary front, is a front that is not moving. If a stationary front is around, and a low pressure center is around, it is possible that there is heavy amounts of precipitation.

Occluded Fronts An occluded front develops when a cold front catches a warm front. For a maturing cyclone, a warm front is progressing northward ahead of the storm center while a cold front is sweeping southeastward. Ahead of the occluded front, temperatures were in the low 40's, while temperatures behind the front were in the 20's and 30's. The air mass behind the front Is also drier. Winds behind the front are from the west or southwest. Also, winds ahead of the occluded front are north-east. Rain showers or snow can occur behind the front.

Dry Lines Air will be much drier after the boundary moves through. Storms are possible as the dryline approaches. The temperature may rise after the dryline passes through, since dry air heats up more quickly than moist air. A dryline is a boundary that separates a moist air mass from a dry air mass. East of the dryline winds from the southeast. Dry lines could lead to the development of thunderstorms along and ahead of the dryline in a manner similar to how thunderstorms develop along cold fronts.

Predicted Weather For predicting weather we used Persistent Forecasting in the short range. Friday – Periods of rain ending in morning, Mix of Sun and Cloud, and a high of plus 15°C Saturday – Cloudy with a chance of rain, and a high of plus 14°C Sunday – Mix of Sun and cloud high of 15°C