Weather forecasting

[DBusby]

Why is it difficult to ensure local weather forecasts accurate? Why is it difficult to ensure longterm weather forecasts are accurate?

[andy hughes]

I'm assuming you refer to forcasting for the British isles? The problems are caused by the frequently changing climate conditions in Europe as a whole, combined with the fact that the British isles is a relatively small land mass, which makes accurate forcasting difficult. The rapidly changing conditions make forecasting in more than general virtually impossible, although as data collection improves with advancing technology, so does the ability to track weather fronts more accurately, although it will never be as predictable as the 'Scorchio' forcasts some of our continental neighbours.

[incitatus]

have you heard of the butterfly wing effect? The reason forecasting is impossible is due to the idea of chaos theroy. in a chaotic system very small changes in starting conditions produce very large changes in the end result. an example would be dropping ink drop by drop onto paper from a fixed height. each drop is the same size, the height is the same but all the shapes are different. Weather is a chaotic system. you can predict with reasonable accuracy up to a certain time limit (which is about three days) and after that all the small effects you cant measure (like someone having mowed the lawn, which allows the wind to blow faster) produce too much random change. Its called the butterfly wing effect because in theory a butterfly flapping its wings in borneo would turn into a tornado in the us three days later.

[incitatus]

so in order to accurately predict the weather you need a totally accurate picture of where everything is and what it is doing. which we havent got.

[archbishop]

Actually if you predict that the weather tomorrow will be the same as today, you will be right 70% of the time.

[archbishop]

I think the Met office forecasts are right 60% of the time.

[Ewood27]

Also don't forget you only remember the forecasts that were wrong, never the ones that were right.

Many critics, no defenders,
Weather men have two regrets.
When we're right no-one remembers:
When we're wrong no-one forgets.

[Hellion]

Try BBCi five day weather forecast you put in your post code and you get weather report from your nearest weather station, however you need to look at it each day as the predictions are contantly upgraded as conditions change-see incitatus