'Get the Candles In' briefing now online

Post by **clv101** » 02 Nov 2005, 15:16

Yeah, when I used that graph on Vital Trivia what I really wanted was just one of average winter temperatures over the last 100 years or so. All I could find was annual data though. If anyone has winter averages I'd like to see what (if any) the recent increase looks like.

Joe · Post by **Joe** » 02 Nov 2005, 15:16

Metcheck's official winter forecast.

The Winter of 2005/6 across the British Isles is expected to rank alongside the one of 2004/5 with the same expected level of frequency of cold weather incursions. However, these spells are expected to be colder than those of last year.

The winter as a whole is unlikely to deviate significantly from average values, however with the UK becoming accustomed to traditionally milder winters in recent years, this winter is likely to appear colder than normal, however we are expecting final figures to show values at or slightly above average.

grinu · Post by **grinu** » 03 Nov 2005, 07:27

Metcheck are the ones who got it wrong the last time. Last year they said it was going to be a big chill, whilst met office predicted it would be warm. This year the met office are predicting a chill, and met check are saying it will be mild.

Post by **clv101** » 03 Nov 2005, 22:01

Metcheck wrote:The Winter of 2005/6 across the British Isles is expected to rank alongside the one of 2004/5 with the same expected level of frequency of cold weather incursions.

*tong in cheek* aren't forecasts said to 60% accurate if you just say tomorrows weather will be the same as today's.

Post by **mikepepler** » 04 Nov 2005, 10:31

clv101 wrote:*tong in cheek* aren't forecasts said to 60% accurate if you just say tomorrows weather will be the same as today's.

Yes, I've heard that too, though I think it's just for the UK. It probably applies elsewhere too, but with a different percentage.

I wonder if they key thing with these seasonal forecasts is this: If the Met Office says it's 60% sure the winter will be among the coldest, it does not also mean the opposite - that they're 40% sure it will be among the warmest. It should be presented as a cumulative probability. For example, they might give their confidence on the average temperatures being below a certain value like this:

-10C 0%
-5C 1%
-4C 2%
-3C 5%
-2C 7%
-1C 10%
0C 20%
1C 30%
....
10C 100%
11C 100%

so they'd be 100% sure the average winter temperature will be below 10C, and also 100% sure it will be above -10C. If you plot it out as a graph you can then see where most of the area is, and that's where the greatest probability lies too.

The question is, has anyone ever seen them present the data like this? I don't think I have.

Also, I start the meteorology module of my MSc next week, so I'll ask the lecturer how it all works, and if he has any hot (or cold?) tips for winter!

peaky · Post by **peaky** » 04 Nov 2005, 14:06

"Lies, damned lies, and statistics"