Why are weather forcasters wrong so much?

Question

Where I live, they are constantly getting it wrong. They promise sunshine for the next 3 days and then that very night it rains!!
What is up with these clowns?

This morning they called for a sunny day. About an hour ago it started raining. I mean, c'mon....!!!

Answer 1

They are only making educated guesses. They try to pretend to know what is going on so when the half of the time that they are right they are like, "Ohhh, look we can predict the future!"

Answer 2

Think of it this way. Take a glass of water, and then add a drop of ink into it. Notice how the ink slowly disperses through the water?

Now suppose you were asked to predict how the ink will disperse, but let's say that the starting conditions keep changing. Maybe the height from which the drop of ink is released gets changed, or maybe the depth of the water get's changed, or its temperature, or the shape of the glass, etc.

Each of these small changes can affect the way the drop of ink disperses.

This is called "chaos theory" - that minute differences in the starting conditions can have drastic effects on the final outcome. You might have even heard of the idea that a flapping of a butterfly's wings in China can affect how strong the hurricane is in New Orleans.

And that's the problem with weather predictions. Since small changes can result in major differences in the final outcome and it is difficult to keep track of every detail that can affect the weather, then weather predictions can only go so far (until we have better models that can factor in small details, or at least rank these details in terms of importance/impact on the weather pattern).

Answer 3

Actually forecasters are getting better at predicting the weather. They are almost 100% right in my area. The weather is always changing. It might seem like it is going to be sunny and then some stray rain clouds might come along and it rain instead. On the other hand you might have bad weather forecasters. Not all of them are good at what they do. Try watching the weather channel. They predict the right weather most of the time.

Answer 4

Weather prediction is more an art than a science, because the weather is not a fully predictable system. It is considered a tough problem because of the chaotic nature of the system.

In theory, if we knew everything about the weather, we might be able to make better predictions, but after about 3 or 4 days, we would be unable to say any more. We must constantly update the information and try to stay on top of the changes.

Presently, we make models of the atmosphere in supercomputers and we break the air into boxes of one cubic meter. We put the temperature, humidity, and direction of airflow in each box in the simulation and then add the energy from sunlight.

The forecaster's model must take mountains into effect, count in the heat energy in oceans and lakes, and also the latent heat of evaporation in the moisture in the air (a fancy term for the heat energy there is in water vapor).

Then they must model changes of state- from vapor to water to ice, and back again, and try to make sense of literally trillions of pieces of data. it is a very difficult job.

In places where the landscape changes, it can have a major effect on weather elsewhere over time. Ocean currents that carry heat must be figured in, and the model gets huge and unwieldy fast.

The answer is to break the air into smaller boxes and try an even more ambitious simulation, and that is something that is being worked on. A higher resolution model of our atmosphere produces even better and more accurate results in a forecast. But going from 1 meter cubes to 0.1 meter cubes means computing a thousand times more values just to get the same forecast with a day or so better lead time or accuracy. It means more sonobuoys and weather satellites, and more time gathering the data for the computer model.

Answer 5

The word 'forecast', or predict, probably explains a lot of it. Between dealing with wind, which is measurable but not really predictable, and temperatures, which rely on the fronts that the wind moves, there is a wide degree of variability. But nobody wants to see a weatherperson say that. They want a number and a forecast. So, it boils down to that. Similar to the way that nobody wants to hear "any given Sunday..." when calling a bookie about a football bet. They want a prediction.

Answer 6

Don't be too hard on them. It could be that their information isn't very up to date. But also, weather systems are notorious for changing direction at the last minute, thus changing weather conditions in any particular area. Weathermen can't always predict which way a weather system will go because of this.

Answer 7

I never believe in them

Answer 8

the conditions change rapidly that is why it is hard to forcast correct weather.............