how far ahead can weather men actually predicte the weather?

Question

like i heard it was only three days, is that true? and then they just guess for the rest of the week?

Answer 1

This depends on the weather regime which is present. In some cases, even the next day or 2 are very questionable - e.g., severe weather outbreaks which are determined by small changes in atmospheric stability and energy distribution. Scattered showers or areas of them which can be hard to predict the same day. In other cases, it can be quite predictable 5 days in advance or more. Sometimes a High predominates and persists over a region for a week. In such a case, you can put down 0-10% for precipitation the entire week. Or it can be a well-defined trof during winter which is predicted to cross North America. In several such cases, the passage of a storm system and a cold front can be predicted to within hours or less 5 days in advance (I did that and got a midnight minimum temperature correct 4 days from forecast time for a contest). That is not typical - rather the forecasts generally degrade with time. i.e., there's no point they "stop being accurate", they just become less and less so.

The 3 to 9 (or so) day time period is where they degrade a little quicker though - which is why people generally perceive accuracy as being lost at day 3. After that, climatology can be used as a forecast and and eventually there is no degradation (say around 2-3 weeks) because there is so little predictability. I.e., a forecast of climatology at day 15 is just about as good as at day 50.

At some locations in Hawaii, the weather is the same almost every day - showers develop and occur which you can set your watch by as people claim (with some exaggeration I'm sure).

Answer 2

The accuracy only goes out about 3 days, but the rest is more than just guessing. It's a combination of weather models, climo, current weather patterns, and their own knowledge of the weather, among other things. It's hard to be accurate past 3 days because the smallest changes can affect the weather.

Answer 3

nobody can predict the weather. Just as nobody can ever predict human nature and the stock market. We only speclate about them and never predict or control it

Answer 4

Depends upon the Situation if it's vey foggy then not possible for more than 2Days

Answer 5

umm no they cant even predict on the actual day yesterday in my town was soposed to rain all morning.. not one drop (thank god cuz i was on a boat)

Answer 6

latest is 5 days. None is exact.