Weather forecasting question
 

So....the BBC, ITV, Sky all present the weather each day. The 'weatherpeople' presenting are all trained meteorologists I guess. Question of the day in our office is how are the longer (3 day) forecasts calculated. Does each program do it individually, or is there one great supercomputer, sponsored by the government maybe, which does the forecasts?
Anyone know? Watkins?
Rgds
Chuckster

Hi Chuckster,

There are a number of differing models that a run on super computers and the forcests are made from there outputs.

www.theweatheroutlook.com is a good place to start.

Isn't it purely based on info they gather and interpret from the MET Office? Thats why all 3 of those channels can give different predictions?

its gonna be sunny, snowy, and rainy on Monday!!

LOL

BB:)

BBC used to use a system called MISTY (Meterological information something something) The forecasters would get all the info from that and then use computer modelling to work out what was going to happen for the next 10 days. The model was intelligent, so could look at the actual weather for 10 days after the last time the conditions were similar.

Sounds like it should work, but you probably need to have about 4000 years of historical info before predictions beyond 2 days are remotely accurate

All cool stuff thanks folks.
C
:)

Judging by the accuracy sometimes I reckon they use an old bit of seaweed and other assorted folklore:

Horses run fast before a violent storm or before windy conditions.

Pigs gather leaves and straw before a storm.

Flowers close up before a storm.

If the bull leads the cows to pasture, expect rain; if
the cows precede the bull, the weather will be uncertain.

Expect rain and maybe severe weather when dogs eat grass.
(This almost always happens before we have a major oubreak of tornadoes)

Wolves always howl more before a storm.

When the rooster goes crowing to bed, he will rise with a watery head.

Ants are busy, gnats bite, crickets sing louder then usual
spiders come down from their webs, and flies gather in
houses just before rain and possible severe storms.

Evening red and morning gray Are sure signs of a fine day.

Evening gray and morning red, put on your hat or you'll wet your head.

When small clouds join and thickne, expect rain.

Dandelion blossoms close before a storm.

If autumn leaves are slow to fall, prepare for a cold winter..

When the leaves of trees turn over, it foretells windy
conditions and possible severe weather

Redbirds or Blubirds chatter when it's going to rain

Birds on a telephone wire indicate the coming of rain.

Before a storm, cows will lie down and refuse to go out to pasture.

When spiders weave their webs by Noon, fine weather is coming soon.
If wasps build their nests high, the winter will be long and harsh.

When it is evening you say, "It will be fair, for the sky is red." And in the morning,
"It will be stormy today, for the sky is red and threatening."

:D

Forecasts are pretty accurate for a 48 hour period. But the further ahead you try to forecast, the more uncertainty there is with the mathematical models.

The BBC definitely use trained meteorologists, they are seconded from the Met Office to BBC duty. Not all the weather forecasters are trained professionals, some are just eye candy to make you feel better when they give you the bad news for a bank holiday weekend. Ulrika Jonsson started her career doing weather on TV-am, and she was never trained in meteorology.

My Dear Chucky-Egg,

It is more complicated than you can possibly imagine, it fries my brain and I'm involved ;)

Easiest thing to do is push you into reading this lot. Some of it is a little out of date, but I understand it is being updated at the moment.

Go and read all that, then come back and I'll test you on it. ;)

Cheers

Ian

Thanks for that Ian. My question was too vague I realise...the only thing we wanted to find out really was where does the predictive data come from...is it all the MET office. The reasoning was that the mathematical modelling involved would probably take some big-arse computing which we figured would be out of budget for the tlelvision companies.
And I can imagine some pretty damn complicated forecasting techniques my friend, you should see some of the modelling involved in pricing Power Reverse Dual Currency Bonds :) Weather derivatives, maybe I should move into trading those! ;)
Ta
Chuck

hmmm - if it is so complicated now and you always get it wrong maybe it is time for a simpler model.

Predictive seaweed observation??

This year they said the summer won't be as hot as last year. How on earth can they work that out??

akshay, that 'prediction' is just some fools applying statistics and forecasting off that...basically last year was very very hot, so we need a cool down to maintain the 'average' temperatures observed over the past 50 years.
It's not very scientific, and it's not really that much of a gamble either..considering how crazy last summer was.
C

Chuck,

To answer your question there are a number of models available (GFS, UKMO, GEM, ECMWF, JMA) They are all regarded as having differing reliabilities based on the curreny condiotions. You will probably find that the forecasts are made from an overall assessment of all the available models.

guess work? flip a coin?

:D

Morning Chuck sir!

Oh I love the bit about presenters all being trained meteorologists.

That's why the Yorkshire TV one referred to a "Spring Solstice" last year...........I'm sure she meant "equinox".

Alcazar:D: