Boards forecast contest May 2016

Table of forecasts for May 2016

FORECASTER __________ IMT _ MAX _ MIN _ PRC _ SUN __ Max rain, loc'n

lostinashford ___________12.2 _ 23.0 _ -1.7 _ 110 _ 109 __ 19th Roches Point
Joe Public _____________ 11.9 _ 22.9 _ -2.9 _ 089 _ 110 ___ 2nd Knock (19mm)
Jpmarn________________11.8 _ 26.8 _ -0.5 _ 110 _ 095 __ 10th Cork (32mm)
mickger844posts _______ 11.7 _ 22.0 _ -1.6 _ 091 _ 109 __ 20th Valentia
Rikand ______ (-5) _____ 11.5 _ 23.0 _ -1.0 _ 090 _ 120 __ 24th Cork
Tae laidir _____________ 11.5 _ 21.5 _ -0.1 _ 115 _ 100 __ 24th Mace Head
waterways ____________ 11.4 _ 26.6 _ -1.4 _ 102 _ 122 __ 25th Malin Head (25mm)
200motels_____________11.4 _ 22.5 _ -1.0 _ 103 _ 106 __ 29th Cork
DOCARCH _____________11.4 _ 19.8 _ -1.3 _ 095 _ 108 __ 11th Valentia (23mm)
Lumi _________________11.3 _ 21.2 _ -0.7 _ 090 _ 105 __ 20th Sherkin (19mm)
Dacogawa ____________ 11.2 _ 24.4 _ -1.0 _ 110 _ 099 __ 19th Valentia

Con Sensus ___________ 11.2 _ 22.1 _ -1.0 _ 100 _ 107 __ 18th Valentia

M.T. Cranium __________11.2 _ 24.0 _ -2.0 _ 105 _ 105 __ 30th Cork (45mm)

Norma L ______________ 11.2 _ 23.5 _ -1.5 _ 100 _ 100 __ 31st ???

sryanbruen ___________ 11.2 _ 22.3 _ -1.0 _ 082 _ 110 __ 18th Newport
sunflower3 ____________11.2 _ 21.5 _ -0.5 _ 095 _ 110 __ 26th Valentia
rameire _____ (-4) _____ 11.1 _ 22.1 _ -1.1 _ 098 _ 106 __ 18th Belmullet
JD _________ (-3) _____ 11.1 _ 21.8 _ -0.6 _ 097 _ 108 __ 22nd Valentia
MrSkinner ____________ 11.1 _ 22.1 _ -1.1 _ 091 _ 111 __ 21st Valentia (24.1mm)
John mac _____________11.0 _ 23.7 _ -1.5 _ 105 _ 097 __ 21st Knock (35mm)
Kindred Spirit __ (-1) ___ 11.0 _ 21.0 _ -1.0 _ 095 _ 105 __ 15th Cork
Bsal _________________ 11.0 _ 21.0 _ -1.7 _ 115 _ 100 __ 20th Knock
pauldry _______________10.9 _ 20.3 _ -1.2 _ 106 _ 106 __ 31st Roches Point
Dasa29 _______________10.5 _ 22.0 _ -1.0 _ 110 _ 110 __ 15th Valentia
_____________________________________________________________

22 forecasts so that Con Sensus is mean of 11th and 12th ranked. I set the max rainfall location at Valentia based on seven forecasts for there, meanwhile Cork (5), Knock (3) and Roches Point (2) attracted multiple guesses while the remaining five went to Malin Head, Mace Head, Belmullet, Newport and Sherkin Island. Interesting that nobody chose a location in Leinster or the midlands.

The scoring for NormaL when it comes to location will be half the available points, and I chose 31st as the normal date for heaviest rainfall in May as there is a slight increase from April to June.

Our group consensus seems to indicate a relatively normal month with warmth perhaps slightly favoured, and slightly on the sunny side of normal with quite average rainfall. The guesses for date and location make it look as though many expect a wet end to the month especially near the Atlantic coasts.

I have added some colour coding to indicate forecast extremes (the IMT extremes are easy enough to spot from the table itself).

Yes, further to the above, MAX so far appears to be 17.6 at Oak Park on 1st. Highest yesterday was 16.9 at Moorepark.

MIN as per previous post --1.4 Markree on 6th.

In the rainfall bonus, noting 13.6 mm fell on 2nd at Malin Head. Will only keep track of amounts greater than that from now to end of month. Today will probably register a 25-30 total somewhere central to Connacht.

Scoring for bonus will take two rounds. First a raw score will be generated, then those will be adjusted to the usual rank-ordered series from ten down to zero with two of each unless ties occur which is unlikely given the complexity of the raw scoring.

Raw scoring will go like this -- for what turns out to be the heaviest rainfall, five points available for right location (regardless of the date you predicted) and that will fall off by distance, close locations will get three out of five etc. Then on date you score five points for a direct hit and one point less for each day missed. This would mean that if today held up as the max, scores would be 2 for Jpmarn, 1 for DOCARCH and everyone else too far off the date. So then, we would look for second heaviest rainfall and all of the above would apply except for the maximum being four not five. And for the third heaviest, points would fall off to a maximum of three, close would fall to two. Similar reductions for fourth heaviest (max two, close one point) and fifth heaviest you would need to be right on that to get one point. In that case, if the rainfall on 2nd qualified for fifth place, Joe Public would get a point for his date guess. If it were third he would get three points and I would say two for a fairly close guess (Knock rather than Malin Head). If it were fourth he would get two points for date and one for location.

So then at the end of the month I add up these raw point totals and reorder them, so it may turn out better than it looks to get a couple of points, if the rest of the field happen to miss by a wider margin. But note that for a third place finish for 2nd May, Bsal with Knock would get two points for location and Sryanbruen with Newport would get one point, Rameire with Belmullet also one point, and waterways with Malin Head would scoop three points.

For "close" I will go with locations in same or adjacent county and next level down would be the counties that border with those. The higher scoring dates will require a few extra groupings but we won't go further than half the country to find one point on location of the heaviest rainfall. I will list the results each time we have a candidate and see if anyone objects to how I defined the location points.

So as Malin Head can probably now do no better than second place, it would be

Max points Malin Head = 4 pts
First close ring = Finner, Markree, Knock = 3 pts
Second close ring = other Connacht except Mace Head = 2 pts
Third close ring = Mace Head, midlands, north Leinster = 1pt

If Malin Head moved back into first place with a later result, all of the above would still apply and max points would be 5 instead of 4 (no extra ring).

As we have no guesses in Leinster anyway, some of this remains academic.

Nothing over 10 mm on Sunday 8th at reporting stations, possibly in between though. Meanwhile max of 21.5 (Markree) already exceeded by 22 Belmullet and potential for 23-24 as already reported at Donegal Airport and Sligo airport, two locations that don't seem to be part of the club of either yesterday's weather or the Monthly Summary so we cannot count these readings (yet).

We are probably into mercy rule territory for MAX already, hard to see how very many people score much from anything between 25 and 25.5. So if that's the outcome don't worry, the outcome will be lenient.

JP, after reading your question I have to admit I don't quite understand it, but here's what I'm thinking, maybe this will clear it up.

Mercy rule applies to distribution of scores not to any one score. The lists of minimum progression of scores were set out some number of years back and I would have to do a bit of hunting but the basic idea is that somebody has to score at least 23/25 on IMT and 18/20 on MAX or MIN, 14/15 on PRC and 10/10 on SUN, then scores below those have to be no less than a series that loses one point per place down to 50% then allows for two scores at each level below that (if necessary) so for MAX you would see 18, 16, 14, 13, 12, 11, 10, 9, 9, etc but the doubles only last as long as necessary to end the progression at 0 for low score, usually with 23-25 entrants we need all those doubles to fill out the scoring.

I realize this can penalize good forecasts relatively speaking on rare occasions but almost always when this rule is applied, the gain per person is relatively equal in value and the main point of it is not to inflate the scores but to make the various months roughly equal so that the 10/12 rule for the contest high score at end of year is not unduly distorted by which months a person happened to do well in, or miss for that matter.

However, the rule has the option of allowing any higher scores in the sequence that are earned by the usual method. If you were right on and then waterways was 2 points off, then the sequence would run 20, 18, 14, 13 etc, preserving the minimum progression but rewarding the acccurate forecasts, dropping to the minimum progression as soon as no raw score was better. This is where I suppose it might appear a bit unfair, but it has rarely happened that one or two people have been right on an extreme event and everyone else way off it. Usually the mercy rule comes in when the whole field is off the mark, some more than others and few raw scores will be generated.

I can always amend the progression slightly if I feel that it is not fairly equalizing the month's outcome, but anyway that reminds me, Belmullet was 25.4 which at the moment would give dacogawa 10 points from raw scores, waterways 8 and then the only others to get any points would be JPmarn and myself at 6 and John mac with 3. (had to edit that as I thought I saw 25.6, apparently not)

All of these would go up about the same amount (these five would score 18, 16, 14, 14, 12 because of the tie) then the rest of the field would come into play with lower scores. Where this is fair, I think, is that it still differentiates a MAX forecast of 23 (who will get about 10 points) from a 20 (who will score lower). If we went with raw score there would be no differential for three quarters of the field. Anyway, it's just the old bell curve system used when the test was too hard in school (how did I know that? don't ask).

Meanwhile, in other news, Sherkin Island and its 19.0 mm of rain yesterday has now moved into the lead for Wettest Location. Lumi will gain the maximum number of points possible from this event's final ranking (5 if it's the wettest one). Cork and Roches Point will be considered second ring, Valentia, Shannon, Oak Park and JC will come in at second ring and if we need more rings those will radiate out as far as maybe Mace Head and Casement for the outer one.

Just for later clarity, the Max rainfall list after 9th in rank order is:

1. 19.0 _ Sherkin (9th)
2. 14.4 _ Mountdillon (7th)
3. 13.6 _ Malin Head (2nd)

For date, Jpmarn stands to gain 4/5 if this one holds up, or 3/4 if it's second, etc. Then DOCARCH will have one fewer points in each case. Nobody else is close enough to gain any points from this date. So it's on to today's opportunity and as most of us went second half of month, we will be searching the FI portions of the GFS for tempting charts (me later than most).