The average weather forecast is basically a simple scientifically based estimation of weather events which are about to occur. The current weather condition at any given time of day is based on the existing atmospheric conditions expressed in a series of weather variables accordingly.
The Meteorologist responsible for making the weather forecast must have an adequate knowledge of the weather conditions over a wide area in order for him to make an accurate forecast about the current conditions expected to unfold.
The reliability of the Meteorologist’s forecast will depend solely on that person’s familiarity with prevailing weather conditions of that large area. The decision and forecast of any Meteorologist is based on a specific set of tools. These tools normally include, a Weather Map which is typically used to outlying the specific patterns of distribution of atmospheric pressure, air and land temperatures, wind speeds, and existing humidity at various altitudes within the atmosphere.
Such weather maps have generally be seen to be of two types, which are the surface weather maps which are generated four times each day at six hour intervals showing distribution patterns or rainfall, precipitation and cloud cover; and the upper-air weather maps which have five specific levels and are generated two times on a daily basis within twelve hour intervals.
The weather forecaster will make what is referred to in the field as Surface observations of both land and sea every three hours. Weather stations which are land based will monitor the atmospheric pressure, wind speeds, air temperatures, humidity, visibility, and cloud cover using a set of weather instruments including a barometer, thermometer, wind vane, anemometer, hygrometer, psychomotor, and a rain gauge.
Weather ships, coastal weather stations, and an ocean data buoy have also been used in calculating and observing atmospheric pressures relative to existing seal levels.
Observations in specific weather conditions are compiled, condensed and encoded to be transmitted by either radiophone, facsimile, or teletype to weather centers designed as weather forecasters. The codes are then downloaded and decoded by these weather forecasting stations and then their respective locations plotted against a surface weather map.
The information plotted against the surface weather map is analyzed by inter-connecting similar atmospheric pressure readings at various points with a line carefully taking into account the wind speeds and direction. Such analysis allows the weather station and inadvertently the forecaster to determine possible instances of high and low pressure areas, cold fronts, tropical cyclones and warm fronts.