What factors does a meteorologist using the trends method consider?

The factors considered by a meteorologist using the trends method are:
the speed and direction of the fronts, rain clouds and high and low-pressure zones are determined by mathematical calculations. A meteorologist can forecast or predict where he expects the weather pattern to move to in the future. For example, if a storm is 1000 miles away moving at 250 miles per day, then you can expect it to arrive at a certain destination in 4 days time. The challenge with the trends method is that it does not take into account changes in direction and speed of the weather pattern. It assumes that the speed and direction of the weather pattern will stay the same. 

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