cableitoh 0 Posted January 30, 2010 Share Posted January 30, 2010 The seasonal forecast for Hokkaido showed that there are 50% probability that the average temp will be below normal (cold) & 50% probability that the snowfall will above normal (heavy snowfall). How accurate are these forecasts..?? Link to post Share on other sites
thursday 1 Posted January 30, 2010 Share Posted January 30, 2010 200% accurate. Don't worry. You go to Niseko? Niseko will deliver. Link to post Share on other sites
foreversnow 5 Posted January 30, 2010 Share Posted January 30, 2010 That is exciting news because last week when I looked it was 40% above normal temperatures. Link to post Share on other sites
Tubby Beaver 209 Posted January 30, 2010 Share Posted January 30, 2010 I'm 70% sure that the reports are 80% accurate for at least 20% of the time! Link to post Share on other sites
big-will 7 Posted January 30, 2010 Share Posted January 30, 2010 I believe you only 50% though TB. Last week, that was 60%. Link to post Share on other sites
Tubby Beaver 209 Posted January 30, 2010 Share Posted January 30, 2010 well we can't all be right 100% of the time! Link to post Share on other sites
big-will 7 Posted January 30, 2010 Share Posted January 30, 2010 But you should be trying 100%. 120% even! Link to post Share on other sites
Tubby Beaver 209 Posted January 30, 2010 Share Posted January 30, 2010 watch what you say, if JA hears that you're gonna work 120% harder then he'll be 300% mad!! Link to post Share on other sites
big-will 7 Posted January 30, 2010 Share Posted January 30, 2010 Got to admit I 100% dislike such "over 100%" comments myself. Link to post Share on other sites
cableitoh 0 Posted January 30, 2010 Author Share Posted January 30, 2010 Hey people, what all these 100%, 105%, 300% or 40% - 50% about..!? Link to post Share on other sites
cableitoh 0 Posted January 30, 2010 Author Share Posted January 30, 2010 Ok, let me ask the question again, how accurate are the JMA seasonal forecasts for Hokkaido.!? Link to post Share on other sites
Tubby Beaver 209 Posted January 30, 2010 Share Posted January 30, 2010 sorry Cableitoh....just pulling your leg!! still drunk from last night Link to post Share on other sites
cableitoh 0 Posted January 30, 2010 Author Share Posted January 30, 2010 Sounds like you have 100% fun last night..!! Ops..!! got ya!! Link to post Share on other sites
cram400 0 Posted January 31, 2010 Share Posted January 31, 2010 not sure about accuracy, but all I know is that the latest forecast for February (released on Friday, Jan 29) is indeed looking good for all areas from Hokkaido all the way to Gifu in Honshu.. High probability for below average temps and above average snowfall.. If this forecast holds true this will easily be the best season Japan as a whole has had in 4-5 seasons, me thinks.. Link to post Share on other sites
cableitoh 0 Posted January 31, 2010 Author Share Posted January 31, 2010 100% sounds fun for the month of Feb in Niseko. Hope will be plenty of powder when I get there. Link to post Share on other sites
JA2340 16 Posted January 31, 2010 Share Posted January 31, 2010 74.3% of statistics are made up! Link to post Share on other sites
JA2340 16 Posted January 31, 2010 Share Posted January 31, 2010 On a serious not, however, and in relation to the OP 's question, accuracy of predictions is difficult. When they say 50% possibility of above average whatever ... they mean that there is an equal chance of it being above and below average. At that sort of level, they are really saying that they have no idea! Link to post Share on other sites
tripler 0 Posted January 31, 2010 Share Posted January 31, 2010 if forecast sites were at all honest, they'd show their PAST forecasts next to actual past REPORTED weather. It's like putting up a currency exchange graph only showing the future but never the past - pretty weird... Link to post Share on other sites
Go Native 70 Posted January 31, 2010 Share Posted January 31, 2010 The current run of the forecast for 30 Jan to 28 Feb has the probabilities of 50:40:10 for temperature and 20:30:50 for snowfall. For the temperature this is not meaning there's a 50/50 chance of above or below. There is a 50% probability that the temps will be below the long term average and only a 10% probability that they will be higher. So basically there is a much greater probability that temps will be lower than higher. There is a reasonable probability that they will be around average but overall the weighted probability is much greater for below average than above. Same with the snowfall there's currently a much higher probability that snowfall will be above average than below. Like all long term forecasts the longer out you attempt to forecast the less accurate the results will be. Within 1 month, as this forecast is for, they are generally reasonably accurate. Beyond a month the accuracy drops off considerably. Link to post Share on other sites
tripler 0 Posted January 31, 2010 Share Posted January 31, 2010 Originally Posted By: Go Native There is a 50% probability that the temps will be below the long term average and only a 10% probability that they will be higher. How long's the long term? Link to post Share on other sites
Go Native 70 Posted January 31, 2010 Share Posted January 31, 2010 At this stage they're looking at around average temps and snowfall through March from central Honshu up to Hokkaido and probably a little above average temps in April. I don't take much notice of forecasts that far out myself. They're little better than an educated guesses. Link to post Share on other sites
tripler 0 Posted January 31, 2010 Share Posted January 31, 2010 No, I mean how many years is the "long term" they get an average from to compare with? eg. 5, 10 or 20? Link to post Share on other sites
JA2340 16 Posted February 1, 2010 Share Posted February 1, 2010 I suspect, at least the way Aus climate forecasters work, they use the total record. That is, if they have records for 120 years, then the "long term average" is from the 120 years. Link to post Share on other sites
cableitoh 0 Posted February 6, 2010 Author Share Posted February 6, 2010 The latest seasonal forecast has been updated at the JMA. The snowfall chart (6th February - 5th March) show a 40% probability below average. The average temp (20th February - 5th March) show a 40% above normal in Hokkaido. From today's Niseko Now report has a reading of -9C (bottom) & -17 (top), how accurate is the forecast.?? http://www.snowjapan.com/e/daily/niseko-now.php Link to post Share on other sites
SKI 15 Posted February 6, 2010 Share Posted February 6, 2010 What are you getting so worked up about. A forecast is a FORECAST! Link to post Share on other sites
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