The purpose of short range forecasting Essay

Short range forecasting is a relatively short term and the surface weather system moved at steady rate. The purpose of short range forecast is to give different users with information on anticipated weather over the coming of two to three days for the particular sites in the areas of few million square km. So that essential precautions can be ready and damage can be reduce based on the bad weather conditions. In the previous day, upper air chart was used as a tool to predict the location of surface storm may develop and where the pressure system aloft may weaken or intensify. But in present day, numerical weather prediction is frequently used due to powerful of computer and electronic devices which can analyse huge quantities of data with faster speed. The computer will plot and analyse data together with predicting the weather using mathematical equation which called numerical weather prediction. The mathematical model has many mathematic equations that show how the atmospheric pressure, temperature, winds and moisture will change with time. The model only shows the approximate formulated according to atmosphere behaviour but not the real atmosphere. The prognostic chart is the final forecast chart represent the atmosphere at a specify future time and as a guide to predict the weather.
There are many models in the present day but each model may produce different interpretation for the same projected atmospheric level and time. Forecaster have to know how suitable a model on certain situation and the weakness and strength of each model, only then he or she can make a prediction from the guidance of the computer's result. However, these model may go wrong as the models do not have global coverage, some model make assumptions about the atmosphere which cannot be suit on every situation and computers are not able to interpret too many factors which influence the weather. There is advantages and disadvantages of the numerical weather modelling. The advantages are this forecast method do not need development data set of the historical model data, can improve with the enhancement of raw model forecast and varies of predictors can be used which providing a better fit to the forecast data. But the disadvantages of this model is the errors cannot be accounted for, the deterioration of the model forecasts with lead time cannot be accounted and vital model parameters as predictors cannot be used.
Another forecast method is called the statistical forecast in which the results are made routinely of the weather pattern and elements regarding to the past performance of the computer models. This forecast made predictions which are statistically based on analogue forecast corrections into computer's model result and is usually based on probability. Model output statistics (MOS) is a statistical post-processing which is used to improve the numerical weather model ability to forecast by relating all the model outputs for observation and extra model data. Both the numerical weather modelling and Model output statistics use multiple regression equations and consist of high range of predictor variables.