When?

When are they going to admit their short range forecasting is pretty crap too?

As an example I told my son on saturday that we wouldn't be going out on sunday because the forecast was for heavy rain. There were even weather warnings in place. I watched the late forecast and they were still forecasting heavy rain for sunday. So eight hours later I got out of bed to glorious sunshine. Checked the forecast and it said sunny periods. No mention that in eight hours the forecast had totally changed. Later on TV one forecaster had the decency to mention the error, except that he said that the weather had done something unexpected. So it seems that it's never the met office's fault when they get it wrong, it's the fault of the weather for not doing what they expected it to do.

We've had snow forecast at least three times in the last few weeks only for there to be no snow. And then this week they forecast a day that was apparently going to be precipitation free for the whole country. Guess what. It snowed.

Seasonal forecasts? Monthly forecasts? They have trouble getting the weather right a few hours in advance.

What's that you say? They have statistics that show how accurate their forecats are? Well sure they do, but that's easy. Here's a little excercise for you: Nip to www.meto.gov.uk and look up the forecast for your home town for next tuesday. Pop back at least a couple of times a day until next tuesday and notice how the forecast changes. Keep a record and I'm sure you'll find that one of the variations turns out to be accurate. So if the Met Orifice keep a record of how many days weather they managed to forecast accurately then they can probably chalk up close to 365. However what if they kept a record of the number of inaccurate forecasts made?

Historical forecasting

Saw a study somewhere that was testing prediction models. As a base they used a prediction model that said "the weather will be the same as on this day last year". On average, it was the most reliable model.

to be fair

they actually predicted a 60% chance of it being a very hot summer.

which might have been perfectly accurate.. it was the press release and the media that got it wrong.

Big and strange

Do the Met not mean that the UK is too *small* and strange to forecast? My impression is that continental forecasts are usually more accurate. In summer it's always hellish hot, and in winter it's always devastatingly cold.

Is the UK, a smallish island, subject to the vagiaries of oceanic weather, with its cyclones and occluded fronts piling in from the west?

Mere idle speculation on my part. Much like a long-range forecast, I suppose.

For Long-Range Forecasting...

The Old Farmer's Almanac in the United States claims to have a reasonable record... while one can't do much far in advance, reminding people of our place in the El Nino/La Nina cycle, for example, can be valid.

What do you do with a 60% forecast ?

Really ? Thats not a hypothetical question: the Met Office (and other met services) are loath

to make public there long-term forecasts, because they know they are only 60% likely.

But they will be ripped to shreds if you have a forecast for a wet / dry summer and don't release it, even if you're only 60% sure.

Lots of fields (farming, seasonal foods, etc) have to make decisions with no information, and plant / make ice cream based on guesses. Your guess is better than theirs, and they want to know even if you've only a 60% chance.

A lot of work is going on with long-range forecasts : we know (sort of) what we need to do to improve them, but its a matter of time and work (better ocean data assimilation, for example). They will always be probabiistic and less useful than short-term forecasts, but being able to say "Next month has a 70% chance of being dry; postpone planting" is worth a fortune to forresters, for example.

Not just their long range forecasts

but their 5 day ones ain't too lucky, either

Looking at yesterdays (thursdays) forecast for the next 5 days, showed I could expect:

Thursday: Sunny Intervals

Friday: Sunny intervals

Saturday: Sunny

Sunday: Sunny

Monday: Sunny intervals

by today, that had all changed. We're now told to look out for

Friday White cloud

Saturday: Light rain

Sunday: Sunny - yay! one that (still) matches

Monday: Sunny intervals - strewth! two.

So not only did they change their minds about what fridays weather would be, with 1 days notice, but they've either messed up thursdays forceast for saturday, or fridays (or both) since the two conflicting forecasts can't both be correct. So not only is the 5 day forecast pants, but the 1 day forecast is, too.

The point about forecasting is that it shouldn't change if it's accurate. As soon as you change a forecast (or any other prediction, come to that) it means you think the earlier one was a mistake - or that you made it without considering enough information - neither being a particularly clever thing to do. As it is, today turned out to be sunny intervals (which is what they said it would be on thursday), rather than the white cloud they forecast this morning.

Maybe weather forecasting is like standards in I.T. If you don't like the one you've got, just pick another.

Mystic Met Office abandons long range forecasts

Strongly suspect that the title of this piece is factually wrong. Almost certainly, the UKMO have not abandoned long-range forecasts - they've merely stopped public dissemination of those forecasts (ie they've returned to previous practice). They'll continue with internal generation of the LR forecasts and continue to inch along on the very tricky path of improving their accuracy.

A Warning From History

"I do think that, of all the silly, irritating tomfoolishness by which we

are plagued, this "weather-forecast" fraud is about the most aggravating.

It "forecasts" precisely what happened yesterday or a the day before, and

precisely the opposite of what is going to happen to-day."

Doesn't look like things have changed since Jerome K. Jerome's day then.

weatheraction

where is the so called proof that weatheraction were wrong ?, i have followed their weather data for the last 12 months they do not say (like the met) these predictions will be 100% but that there is a good chance due to solar activity and climate models that the weather will be pushed north or south, the latest report can be found at http://www.youtube.com/watch?v=1eSD5bMqCoE

My mum was always right

When she said "It's too cold for snow"

And it never snowed, Fantastic scientist, my mum

She also cooks a wicked beef stew & dumplings

Come to think of it, her Beans on Toast are great too

Way to go MUM, Your a star, cooking and weather forcasting

It pains me to say, (as an expat),.....

But local weather forecasting in America is normally spot on up to a week out. We had snow here in Alabama and they correctly forecast the time of day to within 2hours, the type of snow and the amount..

Is it that...

...they think we're idiots or that they think they are gods?

Visiting foreign countries I note that often the forecasts give you a percentage chance of, for example, rain. That way you are allowed to make up your own mind (b) treated as if you have at least a reasonable level of smarts. In the UK we have the met office telling us that it will rain in this location at this time. Which neither allows you to make up your own mind or allows for the fact that you may have a mind to make up in the first place.

Do they really believe their forecasts are that accurate? Or do they think that we are so stupid we can't apply our own judgement?

"It's going to rain" means "Take your wet weather gear." Whereas "There's a 30% chance of rain" gives you some leeway in deciding what to wear. If you're wearing the wrong clothes in the first scenario it's the forecasters fault, in the latter case it's your own fault.

Take that forecast for last sunday that basically said "it's going to piss down all day". Given that it didn't piss down at all it's safe to assume that, if the forecasters are any use at all, the source used for the broadcast weather forecast probably included some sort of probability of rain. Even if that probability was 90%, telling us that would have made them look less stupid. Likewise the snow they confidently predicted was not going to happen two days later. Had they forecast a 10% chance of snow they'd have looked at least part way competent. But no, on saturday they would not allow that there was a chance of fine weather on sunday and on monday they would not entertain the possibility of snow on tuesday. That's a whole world of fail in just three days' forecasts.

Sigh, let's face it.

Anything more than three days' forecast is a guess.

I've heard of a much more reliable "stick and string" method. (forgiveness if you've heard it before).

Jam a stick in the ground, tie a string at the top.

If the stick and string is wet, it's raining.

If the string is flapping, there's wind.

If the string is stuck out horizontal, it's a strong wind.

If the stick and string is missing, it's a hurricane.

bye bye Met Office

I'd join in the criticism of the Met Office's forecasts, but ever since they decided to distort their maps to shrink Scotland to vanishing point I haven't really been aware of what their forecasts for my part of the world actually *are*.

Accuweather

Last weekend, Accuweather promised an OK weekend. That was good, considering I was going to be up on a 70m diameter dish. Accuweather said wind 7-14 kmh...

The wind reached over 100 kmh.

So much for "accu" weather!!