Sometimes weather forecasting deserves its bad name!
I’m off to Geneva tonight, for a couple of days. It looks like I’ll have a fifteen minute walk from hotel to meeting venue. Do I need a) a raincoat, or b) a warm jacket?
- Weather Underground (and google):
- Tuesday: -8 to 5C, clear (sunny)
- Wednesday: -2 to 7C, clear (sunny)
- BBC Weather:
- Tuesday: -3 to 0C, grey cloud
- Wednesday:-4 to 6C, light snow
- Swiss Met Office:
- Tuesday: -2 to 0C, grey cloud
- Wednesday: -3 to 0C, grey cloud, windy (50% probability)
Of course my money is on the Swiss, so I’m taking a rain coat (which is also wind proof).
The problem of course is that how does the punter know which to believe? Of course for Switzerland, one might imagine the Swiss do best … but beyond that the issue of course is that the weather underground folks are presumably just interpolating out of global NWP. Who knows what resolution? Global models near mountains … not a good idea!
Chris Rusbridge (on Monday 31 January, 2011)
Weather Underground (& hence Google’s default gadget) have got very unreliable recently. One particularly noticeable example: before Christmas they forecast -17 C when Met Office forecast -2 (about right). We have had many similar examples.
It would be good if weather forecasters had a publicly accessible site showing what they forecast vs what actually happened. Slightly tricky as eg Met Office revises forecast several times a day. Something probably doable as a mashup, but I suspect the licence prohibits it :-(.
Bryan (on Tuesday 08 February, 2011)
So, as expected, the Swiss and Met Office gave the most reliable results. Weather underground was hopelessly wrong (although there was an hour of hazy sunshine late on the Wednesday).
Weather forecasters’ create systematic measurements of how good they are, and it’s confounded by the difference between subjective impression, and actual measurements … and uncertain expressions such as “mostly cloudy”.