Cold Surge Forecast Contest

(Year 3)

[Jump to Submission Form] [Information and Results in this year] [Change to Chinese Version] [2007-2008 Winter Cold Surge Page (CHINESE ONLY)]

[Regulations updated on 2007/12/25]

1. History

The Cold Surge Forecast Contest was first organized in the winter of 2005/2006. In the first year of the contest, participants were required to submit their predictions of HKO's minimum temperature during a cold surge/strong northeast monsoon replenishment.

This Forecast Contest is jointly organized by the Hong Kong Weather Watch (HKWW) and the Hong Kong Weather Warning Signal Issuing Centre (HKWWSIC).

2. Current Regulations [Updated]

In the 3rd year of this contest, participants are required to give their predictions on the following areas when "relevant criteria" (to be described below) are fulfilled:

項目符號 Minimum air temperature of the HK OBSERVATORY in a "3-day period" (to be explained below);
項目符號 Minimum air temperature of TA KWU LING in the same "3-day period";
項目符號 Minimum grass temperature of TA KWU LING in the same period.
3. The "Relevant Criteria" [Updated]

This forecast contest will commence whenever HKO predicts a temperature drop of 3 (or more than 3) Celsius degrees in the minimum temperature. Here we denote A as the predicted date with lowest temperature at HKO as shown in their 7-day weather forecast.

項目符號 Case 1: No other temperature drop of at least 3 Celsius degrees is expected in HKO's 7-day weather forecast.

In this case, the submission period will be from 18:00 HKT date A-4 to 12:00 HKT 18:00 HKT date A-2, in which participants are required to predict the minimum temperatures in the interval from date A to date A+2 (hence "3-day period").

e.g. The 7-day weather forecast of HKO is assumed to be as follows:

Date 5/1 6/1 7/1 8/1 9/1 10/1 11/1
Temperature
 (degrees Celsius)		 15-19 14-17 12-14 11-14 11-16 12-17 14-18

　

　

　

Then the submission period will be from 18:00 HKT 4/1 to 12:00 HKT 18:00 HKT 6/1, in which participants are required to predict the minimum temperatures in the period from 8/1 to 10/1.

Note: Whenever there are more than 1 day with lowest predicted temperatures in the 7-day weather forecast, the first occurrence of such temperatures will be taken as the date A.
項目符號 Case 2: There is another temperature drop of at least 3 Celsius degrees expected in HKO's 7-day weather forecast.

This case can be subdivided into two parts. In both parts, we assume B to be the date with minimum predicted temperature of the second surge:

1: B is beyond the period from A to A+2:

In this case, the two temperature drops will be treated separately and two contest rounds will be held.
e.g. The 7-day weather forecast of HKO is assumed to be as follows:

Date 12/2 13/2 14/2 15/2 16/2 17/2 18/2
Temperature
 (degrees Celsius)		 16-20 13-16 14-16 14-17 13-15 10-14 11-15

　

　

　

Then the submission periods and the forecast periods will appear as:
Round 1: Submission from 18:00 HKT 9/2 to 12:00 HKT 18:00 HKT 11/2; Forecast period from 13/2 to 15/2;
Round 2: Submission from 18:00 HKT 13/2 to 12:00 HKT 18:00 HKT 15/2; Forecast period from 17/2 to 19/2.

2: B is within the period from A to A+2:

In this case, the second temperature drop will be ignored; the end of the forecast period will be shortened to 1 day before the second expected minimum temperature occurs.

e.g. The 7-day weather forecast of HKO is assumed to be as follows:

Date 6/12 7/12 8/12 9/12 10/12 11/12 12/12
Temperature
 (degrees Celsius)		 21-25 20-25 17-22 18-22 14-16 15-18 16-19

　

　


Then the submission period will be from 18:00 HKT 4/12 to 12:00 HKT 18:00 HKT 6/12, in which participants are required to predict the minimum temperatures in the period from 8/12 to 9/12 only. The second surge will be completely ignored.

Note: In both parts 1 and 2, the extent of the second surge is calculated by:
temperature drop (T) = (Maximum min. temp. during the period from A to B) - (min. temp. of B). B is regarded as "another temperature drop" only when T is larger than or equal to 3.

項目符號 Other cases

Some possible cases include:

1) HKO changed the 7-day weather forecast so that a temperature drop of 3 Celsius degrees or more is expected, but the change is so late that there is not enough time to hold a new round - in this case this temperature drop will be ignored.

2) HKO changed the 7-day weather forecast so that a temperature drop of 3 Celsius degrees or more is NOT expected anymore, but a new round has already been started - in this case the current round will be suspended if no submissions are received to date, but will continue otherwise.

In case there are any other situations not described above, the submission and the forecast periods will be determined separately by the organizers. The special arrangements regarding such situations will be posted on this page.

The submission and forecast periods of each round of the contest will be made known in the Chatroom of Hong Kong Meteorological Communicating Centre. Therefore you are strongly encouraged to obtain an account there to get the latest information of the Contest.

4. Submitting Your Prediction (Updated)

All submissions must be done There are 3 methods to submit your prediction:

   1. Submit using the form below (the same form is also available at Hong Kong Weather Watch);
   2. Submit in the Chatroom of Hong Kong Meteorological Communicating Centre;
   3. Contact the organizers of the contest directly, or any other methods announced by the organizers.

Please note that only submissions within the stipulated period will be accepted. In case you choose method (1), you need to provide a valid email address also. No matter which method you choose, you are strongly encouraged to submit within the stipulated period, because:
a. If you submit before the allowed period (but after we have announced the commencement time of a particular round), no increment will be granted for early submission (See point 1 in Part 5: Scoring);
b. If you submit after the allowed period or before any indication of a new round is made, your submission will be ignored (since this will be unfair to those who submit before the deadline).

Also, only one submission is allowed per person. you can submit at most once during the stipulated period. Any duplicate submissions will be ignored.

Please use the same name and email address for each round of the contest, or otherwise we cannot obtain an accumulated score for you.

Any request of changes in personal particulars (name/email) must be made by contacting the webmasters of HKWW or HKWWSIC. DO NOT USE THE FORM BELOW for alteration of personal particulars; they will not be entertained.

5. Scoring (Updated)

The process of calculating the scores obtained are as follows:

1. To encourage early submissions, every contestant will be given a percentage for the adjustment of final results (The first one to submit will receive a 30% increment, the next one 27% etc. Negative increments will also be made when the number of contestants exceeds 11).

2. The error (E) of each contestant will be calculated as follows once the minimum temperatures during the forecast period are obtained:

E = (  | forecast min. air temp. at HKO - actual min. air temp. at HKO | * 4 + | forecast min. air temp. at TKL - actual min. air temp. at TKL | + | forecast min. grass temp. at TKL - actual min. grass temp. at TKL | )0.7

E = ( | forecast min. air temp. at HKO - actual min. air temp. at HKO | )1.5 * 100

3. 2/3 of the contestants (after rounding) will be given a score (P) scaled between 0 and 10 (the number of contestants eligible for scoring is denoted as n):

Pi = 10 / (E1 - En+1) * (Ei - En+1), i = 1, 2, 3, ..., n

Ei and Pi in the above formula represent the error of the i th contestant (listed in ascending order) and converted score respectively. This equation ensures that the n contestants will have the score between 0 and 10.

4. The score obtained in (3) will be adjusted using the percentage given in (1). The result is the total score that a participant obtains in that round.

5. The final result of a participant in this year (2007 - 2008) is determined by the summation of the highest scores he/she obtains in two-thirds of the total number of rounds in this season (correct to the nearest integer). Therefore, if a total of 11 rounds are held, the top 7 scores of the participant will be added to give the final result.

6. Note: Since two-thirds of the participants will be awarded scores, the contest will be cancelled if less than 3 submissions are received.

　

Submission Form：

Note again: Please use the same name and email address for each round of the contest.

Name:
Email:
Min. air temp. (HKO)

Information and Results in this year :

Round 1:  (Submission period : 2007/10/6 18:00 - 2007/10/8 12:00, Forecast period : 2007/10/10 - 2007/10/12 , result announced on 2007/10/14)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 2:  (Submission period : 2007/10/30 18:00 - 2007/11/1 12:00, Forecast period : 2007/11/3 - 2007/11/5 , result announced on 2007/11/7)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 3:  (Submission period : 2007/11/16 18:00 - 2007/11/18 12:00, Forecast period : 2007/11/20 - 2007/11/22 , result announced on 2007/11/25)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 4:  (Submission period : 2007/11/24 18:00 - 2007/11/26 12:00, Forecast period : 2007/11/28 - 2007/11/30 , cancelled automatically)

Round 5:  (Submission period : 2007/12/21 18:00 - 2007/12/23 12:00, Forecast period : 2007/12/25 - 2007/12/27 , result announced on 2007/12/30)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 6:  (Submission period : 2007/12/27 18:00 - 2007/12/29 12:00, Forecast period : 2007/12/31 - 2008/01/02 , result announced on 2008/01/05)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 7:  (Submission period : 2008/1/10 18:00 - 2008/1/12 12:00, Forecast period : 2008/1/14 - 2008/01/16 , result announced on 2008/01/19)

Submissions received (ONLY Chinese, Made by hkson)                Result in excel format (Made by David)

Round 8:  (Submission period : 2008/3/19 18:00 - 2008/3/21 12:00, Forecast period : 2008/3/23 - 2008/03/25 , cancelled automatically)

Last modified： 2008/3/22 02:41HKT