Statistical Accuracy of Internet Weather Forecasts

markmcb writes "Brandon Hansen considers the statistical accuracy of popular on-line weather forecast sources and shows who's on target, and on who you probably shouldn't rely. Motivated by a trip to a water park that was spoiled with hail despite a 'clear sky' forecast, he does a nice job of depicting deviations, averages, and overall accuracy in a manner that stats junkies are sure to love."

Whom

[mdsolar]

A preposition is awkward to end a sentence with. But, "whom" is the word "on" is followed by.
--
Solar follows the rules for grammer. http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Possibly the best slashdotted error message ever.

[sammy baby]

"Total Freaking Database Error!"

Best 500 error I've ever seen. (Although I'm not sure it actually sent a 500.)

YIC!

[Guppy06]

Where's the Wii Forecast Channel?

Re:Can we believe the forecasts?

[nomadic]

To my surprise (and right on time), down came the blast of cold air. Soon after was the promised snow/ice.

I remember when a year and a half ago one of the hurricanes was in the Gulf of Mexico, heading almost straight west, and the meteorologists all insisted that the hurricane would make a complete 180 degree turn and head back east and smack into Florida. I didn't believe them. On more than one occasion I publicly stated that this was ridiculous.

I ate a lot of canned food that week.

You can't fool mother nature

[TheHornedOne]

I work for Mother Nature; So I am really getting a kick out of most of these replies. Some of you guys are very good at making it sound like you know what you are talking about. But trust me.... You don't. I think you just want to make yourself sound smart, when in reality you don't know what you are talking about. This is how bad info gets passed around. If you dont know about the topic....Dont make yourself sound like you do. Cos some slashdotters believe anything they hear."

/wrong metasite
//slashies
//dont' kill me

Re:Reliable forcasting method...

[OldBus]

persistence is 75% reliable

Won't this depend where in the world you are? E.g. in desert areas most days are likely to be hot and sunny. Here in England, we consider stable weather for 10 minutes to be persistent.

Obligatory Stats Joke

[frank249]

Nice article but the sample only uses an 'n' of 14 days. I would have more confidence in the means, standard deviations and correlations if the author had used a bigger 'n'. For in stats, as in ethics, the n's do justify the means.

I predict...

[monkeyboythom]

very stormy weather for the poor website linked to in the TFA. I believe the outlook will be dark, followed by intense periods of slashdotting...

Re:What is your source?

[CmdrGravy]

Within half an hour ! That's pretty gosh darn impressive work there sir !

If you wouldn't mind going into a bit more depth I'd love to hear the details of how you knock up these forecasts, at the moment I can only predict the weather for definite maybe 20 - 25 minutes ( using basic optical observations ) in advance and I'd love to shave off those extra 5 minutes but I wonder if it's worth the cost of investing in something like a PC. I've seen portable weather stations you can install in your living room from hippy shops, do you think these would be suitable ?

Re:Just a suggestion...

[flyingfsck]

In Calgary, the weather forecast is just a suggestion. Actual weather can change 20C up or down in a few minutes. One side of the city can have snow and the other side sunshine. Sometimes it snows in July. So I have no idea why all these other wimps are complaining about a thunder shower on a forcasted clear day. I mean, what is the problem with that? The guy should be glad that he didn't get a heat wave followed by 2 feet of snow after the thunder shower...

Re:The more the merrier?

[einnar2000]

I can't help but smile a bit that MSN weather in this test turns out to be the absolutely worst when it comes to accuracy in almost all categories.

That's because MSN is trying to control the weather, not predict it. Trends are for sissies.