Update!

2010-03-15: I fixed the problem with tornado reports showing up on the wrong maps. All of the existing outlooks have been re-scored, now with the correct reports. Sorry for the confusion. — CLC

Introduction

The purpose of this contest is to allow people with an interest in severe weather to try their luck at predicting, as far in advance, where the events will occur during any given period. The object is to define the smallest area that misses the fewest events.

Please note that this is a contest — it's a game! So don't get bent out of shape if things don't go your way, for whatever reason. The administrator will put forth a normal amount of effort to make sure that the site runs reliably, that the data are backed up regularly, and that the scoring algorithm is as fair as possible with a reasonable amount of programming. But we ain't hookin' up no AI algorithms here. (If we did, then nobody would understand the rules, and everybody would still get bent out of shape!) So play the game if you enjoy it, and only play it for the enjoyment. Maybe we'll all learn something from this, but developing sophisticated pattern analysis algorithms is way beyond the scope of what we're doing here. This is simply a place for enthusiasts to have a healthy, good-natured competition, to see who can guess the best. ;)

NWS Outlooks

It has been suggested that the NWS outlooks be imported, making NWS a competitor in this contest. But that's not going to happen, and for a very simple reason. This is a weather contest. We're just competing to see who can guess the best. NWS, on the other hand, issues outlooks as part of their commitment to public safety. The criteria that they use in deciding where and when to assign probabilities of severe weather are very different from the simple scoring algorithm employed on this site. So it would be an apples-and-oranges error to compare what we're doing here to what NWS does, and that sort of misrepresentation wouldn't serve any legitimate purpose.

So, if an NWS forecaster decides to compete here in his/her spare time, that's fine. We'll probably get out butts kicked, but that's OK, if we learn something every now and again. ;) But we're not competing against NWS as it functions in its official capacity.

"Valid" Times

Outlooks will be "valid" for the target time +/- 6 hours. NWS issues outlooks that are valid for an entire day. Of course, NWS has the time to figure out how the conditions are going to change throughout that entire period, but most of us weather freaks don't have that kind of time. So this contest is based on specific target times, and only events occurring within a 12-hour period straddling the target time will matter. So if your target time is 00:00 Z, then look at model maps for that time, and issue an outlook for what you think will be happening within 6 hours of that time. It won't be held against you that events occurred in other places at other times during the day, that you didn't have the time to study.

Scoring

Outlooks can be issued up to 3 days in advance, but no less than 12 hours in advance. The further in advance the outlook is issued, the more points you score. Lead-time scoring will be done in 6 hour increments, since the model maps are only issued every 6 hours. So for example, all of the "24-hour" outlooks will get the same lead-time bonus, even though this will include all outlooks issued 24~29 hours in advance.

The maps issued by other contestants will not become visible until 12 hours before the valid time, at which time no more submissions will be allowed for that time. So no piggy-backing on somebody else's outlooks. :)

To get a high score, you have to define the smallest area that misses the fewest events during the valid period. You'll start off with 100 points, plus points for the number of hours in advance that you issued the outlook. Then points will be detracted for how large the outlook area was. (If your outlook covers the entire country, then you definitely won't miss any events, but this wouldn't be useful information to anyone. So the larger the area, the lower the score.) When the reports come in, you'll get a bonus for the percentage of events that occurred within your outlook polygon, while you'll lose points for any events outside of it. Missed-event penalties will be based on the distance from the event to the outlook polygon. So a missed event 50 miles outside of the poly won't matter much, but a missed event on the other side of the country is going to hurt real bad. :)

If you decide to go with a "less than 2% chance" outlook, and there is an event during the specified valid range, the missed-event penalty will be based on the distance from the upper left corner of the map to the event. So it's actually to your advantage to not go with "less than 2% chance" unless you're really sure that there will be no events.

The way the scoring factors are weighted will be open to public debate, so if you think a great outlook got too low of a score, or a bad outlook got too high of a score, post a message on the associated forum. Then the scoring algorithm will be tweaked, and all outlooks will get re-scored with the new algorithm.

As the scoring algorithm changes, it might lead to a different way of issuing outlooks, and you might want to delete old outlooks that are dragging down your running score. But you cannot selectively delete them. In other words, you can't just delete the outlooks that sucked — you can only delete outlooks one at a time, starting from the oldest. So if the scoring algorithm changes, and you change your outlook strategy accordingly, and/or as you get better at issuing outlooks, you can scrub your earlier outlooks, so they won't be held against you.

Over time, we'll see who can guess the best, but of course, we'll also be reminded that severe weather events are near-random in nature, and on any given day, anything can happen.

Good luck!

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