January 2023 Boards weather forecast contest _ join us this year

Welcome to the 2023 Boards weather forecast contest. Our scoring format is based on the best 10 of 12 monthly forecasts. This allows you to miss one or two, or blow one or two, without being knocked out of the race. There's a secondary contest based on the total score.

For anyone who has been a lurker or an occasional entrant, why not become a regular (at last count there were 22 forecasters who showed up more or less regularly, and half a dozen occasional visitors). You are also forecasting against Normal and the more formidable Con Sensus.

Here's how it works. Every month we predict these five weather elements, and one extra "bonus" question that is a last minute decision based on the weather pattern (or at least it should be, right? ... let's move on) ...

1. Predict the "IMT" or Irish Mean Temperature which is the average for night and day at these five locations: Casement, Mullingar, Claremorris, Oak Park, and Shannon. (In January the normal IMT is 5.1 C). That is worth a maximum of 25 points. You lose one point per 0.1 deg error.
2. Predict the MAX which is the highest reading at any of the 25 regular reporting stations on the met.ie website. Worth 20 points, same error.
3. Predict the MIN, lowest reading, otherwise same idea. Worth 20 points, same error as the first two.
4. Predict the PRC which is the rainfall plus liquid equivalent of any other types of precipitation, as a percentage of normal for the average at eleven locations in Ireland. Those are the five listed in 1 above, plus Malin Head, Belmullet, Ballyhaise, Johnstown Castle (in Wexford), Cork, and Valentia. (worth 15 points, you lose one point for each 3% error, so let's say you predict 120% and the outcome is 129%, then you score 12/15. (what is normal PRC in January you may ask? ... the average for the eleven stations is 111 mm, the south and west get a bit more, the east closer to 65-70 mm. But your forecast should be a percentage rather than an actual amount ... if anyone submits an actual amount, that will be converted using 111 mm).
5. Predict the SUN, hours of sunshine also as a percentage of normal, from stats gathered at six locations around Ireland (Casement, Dublin, Cork, Valentia, Shannon, Belmullet). The average duration of sunshine in January is about 2 hours a day, so if you think we might average 2.4 hours, predict 120% (etc). Worth 10 points and the score is reduced for each multiple of 5% error.
6. BONUS for January __ Predict the maximum temperature on Saturday 7th at Mullingar. (10 points, scores are always by rank order regardless of whether the errors are big or small)
7. A further note on scoring, in cases where more than one third of the entrants would score zero or where the distribution of scores is abnormally low, and it can happen, then we boost scoring using a formula that approximates how scoring usually goes, but you can "hammer" the field by scoring within 2 of a top score in which case anyone else's boost will be reduced by half. Here's an example of how that might work. Let's say it's quite a cold month and you predict an IMT of 1.0 and that is so close that you would score 23/25. So you now have the "hammer" and your score goes to 25, then if the next score might have been only 8/25. instead of going to 24/25, that person will only get 16/25 (half the difference). If the third best forecast was going to have three points, then it would be boosted to 13/25 instead of 23/25. But if nobody has the hammer, the points boosts are more generous. There is an attempt made to pick a scoring pattern that somewhat approximates the differences between forecasts, but it is not overly rigorous so basically when scores are bad, your score will depend mostly on your rank order no matter how big the errors turn out to be. I can say that in the past few years this boost of scoring has been needed about once every two or three months and sometimes for more than one category.

Deadline for entries is usually 0300h on the 1st of each month and you are penalized one point for every four hours late beyond that. However, in January we sometimes have a more lenient start; this year we will only penalize at half that rate for the first 24 hours so any entry on the 1st will not lose much ground.

Please enter in a format like this, as I copy the forecasts and make up a table of entries (if I copy them, it is harder to make mistakes but check what you see).

FORECASTER ________ IMT _ MAX _ MIN _ PRC _ SUN ___ Max Temp 7th Mullingar

M.T. Cranium ________ 5.5 _ 15.2 _ -5.8 _ 090 _ 115 ___ 10.2 (I may edit this before deadline)

Normal _____________5.1 _ 15.5 _ -6.5 _ 100 _ 100 ____ 7.8

(con sensus will be the median of all forecasts other than Normal)

Good luck then if you decide to join in. The threads during the month are interesting as we track the evolution of the contest stats from week to week.