On Wed, 13 Mar 2013 19:38:33 +0000, stuart noble wrote:

On 13/03/2013 17:48, Sacha wrote:
On 2013-03-13 12:01:24 +0000, zaax said:

According forecasters this summer is setting up to be another wet one
just ike last summer. So harvest will be down and floods every where

Given that any reputable met source will tell you that a 5 day forecast
is stretching it, that's not worth a passing thought.

And yet the Met Office make a pile of money selling long range forecasts
to farmers etc. I suppose these must be computer predictions based on
past weather patterns?

Look at http://www.ecmwf.int/.

They do medium range weather forecasts.

There are a lot of huge computers out there trying to predict what the
weather will do but if you are asking if a band of rain will pass over
Kent or Norfolk in six months time then there is no chance.

Short range forecasts are pretty good but then a lot of that is based on
using radar and satellites to watch weather systems heading towards us
across the Atlantic.

I think most of the longer term weather forecasting is probably based on
guessing where the jet stream is going to be in six months time.

Cheers

Dave R

In article , David.WE.Roberts
writes
There are a lot of huge computers out there trying to predict what the
weather will do but if you are asking if a band of rain will pass over
Kent or Norfolk in six months time then there is no chance.

So it will be safe to go out in Kent and Norfolk without a brolly in 6
months time

--
regards andyw

In article ,
David.WE.Roberts wrote:
On Wed, 13 Mar 2013 19:38:33 +0000, stuart noble wrote:
On 13/03/2013 17:48, Sacha wrote:
On 2013-03-13 12:01:24 +0000, zaax said:

According forecasters this summer is setting up to be another wet one
just ike last summer. So harvest will be down and floods every where

Given that any reputable met source will tell you that a 5 day forecast
is stretching it, that's not worth a passing thought.

Actually, if it is described competently and not dumbed down,
they are pretty reliable up to 5 days and can be pushed to 10.

And yet the Met Office make a pile of money selling long range forecasts
to farmers etc. I suppose these must be computer predictions based on
past weather patterns?

Essentially, yes. Plus a lot of modelling of how things might
develop, using a mixture of fluid dynamics and past history to
guide the modelling.

Look at http://www.ecmwf.int/.

They do medium range weather forecasts.

There are a lot of huge computers out there trying to predict what the
weather will do but if you are asking if a band of rain will pass over
Kent or Norfolk in six months time then there is no chance.

Precisely. And it is only recently that the medium range ones have
become even slightly more reliable than just using the past decade's
average. And they are only slightly better, even now! Note that
this is in terms of probabilities and not details.

It was only when the satellites went up that the short term ones
became any better than "The same as the day before".


Regards,
Nick Maclaren.

On 14/03/2013 09:28, David.WE.Roberts wrote:
On Wed, 13 Mar 2013 19:38:33 +0000, stuart noble wrote:

On 13/03/2013 17:48, Sacha wrote:
On 2013-03-13 12:01:24 +0000, zaax said:

According forecasters this summer is setting up to be another wet one
just ike last summer. So harvest will be down and floods every where

Given that any reputable met source will tell you that a 5 day forecast
is stretching it, that's not worth a passing thought.

And yet the Met Office make a pile of money selling long range forecasts
to farmers etc. I suppose these must be computer predictions based on
past weather patterns?

Look at http://www.ecmwf.int/.

They do medium range weather forecasts.

Thanks. Looks like only the first 6 days is free!

There are a lot of huge computers out there trying to predict what the
weather will do but if you are asking if a band of rain will pass over
Kent or Norfolk in six months time then there is no chance.

Short range forecasts are pretty good but then a lot of that is based on
using radar and satellites to watch weather systems heading towards us
across the Atlantic.

I think most of the longer term weather forecasting is probably based on
guessing where the jet stream is going to be in six months time.

Cheers

Dave R