Find solution
What are good long range weather forecasts?

How reliable are long range weather forecasts?

  • I just looked up the forecast for our Summer 2012 in the UK and it seems pretty certain of yet another cloudy wet and unsettled Summer! So i am just wondering how accurate these long range forecasts actually are? Is it possible we could have a summer which turns out to be completely different to what is currently forecast? Thank you.

  • Answer:

    Kar, I am 64 years old and during my life I have been sailing, single handed, tiny sailboats across long distances and now, flying a tiny ultralight aircraft across Europe. The weather forecast has been for me, a matter of life and death more than for most other people. This is why I teach meteorology to aviators and I contribute as a Top Contributor, to this section of Yahoo!Answers. The weather for the next summer cannot be predicted - period! At best, in e.g. a stationary high pressure, we can tell for perhaps three days ahead that the high pressure will persist with clear sky and little wind. That's all! I have seen forecast changing in a matter of hours! In fact, aviation has something called SIGMET to warm between each three hours period of a significant weather change that could be important to aviation like, thunderstorms building up or shear winds. Of course, people will tell you about the El Nino Southern Oscillation (ENSO) that causes this or that, then the North Atlantic Oscillation (NAO) etc. Then I ask you: Do you remember a summer, or any other season, where you noticed a particular type of weather you could attribute to one of those "oscillations?" I think not, and that is my point: If meteorologist can plot curves of temperature, pressure or moisture showing that in a period of a decade, the weather has been so-and-so, the man in the street doesn't notice anything other than ... hum, it's raining or, hum, it's sunny. ... and with this, I rest my case, your honnour! ;-) EDITED: After typing this, I went to see the METAR/TAF for my airfield because I was thinking to fly a bit today. This morning, the wind was 8 knots from the south-west. Now it is: 15 knots from the north-west, gusting to 25 knots. Well ... there goes my week-end flying: that wind coming down from the Norwegian mountains (I live near Oslo) will be extremely turbulent. ... and that's how fast a weather forecast changes!

Michel Verheughe at Yahoo! Answers Visit the source

Was this solution helpful to you?

Other answers

Long range weather forecasts are notoriously unreliable, because of the 'chaotic' (look up the definition of a chaotic system) nature of our weather system. Basically, a weather forecast nowadays is based on a 'weather model' that is run on a very large, incredibly fast computer system (I think that the Met Office in the UK have one of the fastest computer systems that is available, outwith heavily classified defence systems, and even that has difficulties coping with the mathematical complexity of a real weather system - don't blame the forecasters, it's just impossible to accurately 'model' the weather system beyond a few days (at least one that changes so rapidly as a 'maritime' one, like we have) Predicting weather over more than a few days is a thankless task.... You could say that it is rather like a computer playing the board game 'Go'. Computer scientists have cracked chess - all you have to do is throw a lot of computer power at it (oversimplifying a lot, but....)but 'Go' is a whole different kettle of fish. Maybe when computers can play that, they will be ready to tackle weather forecasting beyond two weeks....

Iain

They are not accurate at all and there is no science behind them apart from statistics sometimes. It is possible, using climate variables such as El Niño and the Indian Ocean Dipole, to give a probability of rainfall and temperatures being below or above average over the next few months but that is the best anyone can do. No-one knows what the 2012 summer in the UK will be like and anyone who claims to be able to forecast it is lying to you.

tentofield

I don't think they're all that reliable because the weather can be completely different than what was said. But if we have really hot weather now then we probably will have a bad summer again like last year.

sophie

Not very as they are based on averages.

Manxbiker

50% at best.

Earwigo

Related Q & A:

Just Added Q & A:

Find solution

For every problem there is a solution! Proved by Solucija.

  • Got an issue and looking for advice?

  • Ask Solucija to search every corner of the Web for help.

  • Get workable solutions and helpful tips in a moment.

Just ask Solucija about an issue you face and immediately get a list of ready solutions, answers and tips from other Internet users. We always provide the most suitable and complete answer to your question at the top, along with a few good alternatives below.