1. WMO Workshop on Public Weather Services – Effective Warning Systems David Hui Macao, 18 April 2013

2. Group exercise Create a check list for effective warning system

3. Users’ response Real time data Warning strategy & operations Internal training Public education & outreach Business Contingency Plan warnings Dissemination Identify extreme / hazardous weather Know climatology Understand impacts & users’ requirements Set up warning criteria

4. Considerations when formulating operational warning strategy Tools –Essential vs supporting Value –belated warnings are of little use –early warning with intrinsic flexibility of the system Partners –Understand & work together Pace and Timing –various level to trigger matching actions –time when criteria reached –time that are important for users’ decision making

5. TC warning system in Hong Kong Standby Signal No. 1 Strong Wind Signal No. 3 No. 8 Gale or Storm Signal Increasing Gale or Storm Signal No. 9 Hurricane Signal No. 10 Average no. of TC affecting Hong Kong: 6.4 / year Warning Purpose: High wind and related impact No. of days with warning effective in 2006:20

6. Experience during passage of Vicente NO. 10 NO. 8 Hurricane force Gale force

7. Valued added messages Signa l IssuingCancelling TimeExtract of Messages hh mm dd/mon/yyyy hh mm dd/mon/yyyy 115:4021/Jul/201205:2023/Jul/2012 04:45 LOCAL WINDS ARE EXPECTED TO STRENGTHEN. THE OBSERVATORY WILL ISSUE THE STRONG WIND SIGNAL, NO.3 SHORTLY. 305:2023/Jul/201217:4023/Jul/2012 06:45 THE CHANCE FOR ISSUING THE GALE OR STORM SIGNAL, NO. 8 DURING THE DAY IS NOT HIGH. 11:49 IF VICENTE FURTHER INTENSIFIES OR SPEEDS UP TOWARDS THE COAST OF GUANGDONG, THE OBSERVATORY WILL CONSIDER THE NEED OF ISSUING THE GALE OR STORM SIGNAL NO. 8 AROUND SUNSET. 13:55 LOCAL WINDS ARE EXPECTED TO STRENGTHEN FURTHER. THE OBSERVATORY WILL CONSIDER ISSUING THE GALE OR STORM SIGNAL NO. 8 BETWEEN 5 P.M. AND 8 P.M. 8 NE17:4023/Jul/201223:2023/Jul/2012

8. Hour of the Day that Respondents Most Likely to Access Weather Information

10. Warnings must evolve to survive Enhanced Warning System Changing Needs of society Warning System

11. Evolution of warnings in Hong Kong

12. Warning Process Monitoring & Review Process Design Process Considering Needs of Society & Stakeholders Decision-making/ Response Process Education & Reaching-out Process Development of an Effective Warning System + Operational Strategy

13. Warning Process Monitoring & Review Process Design Process Considering Needs of Society & Stakeholders Decision-making/ Response Process Education & Reaching-out Process Development of an Effective Warning System + Operational Strategy

14. Monitoring & Review Process Forecast Verification  objective score Public Opinion Survey  perception, users’ needs/expectations Focus group  testing new services/products Liaison group  tailor-make products for special users Talks, public lectures  collecting opinion in casual way News reports  immediate public perception

15. Weather forecast in qualitative terms Mainly cloudy. A few rain patches and squally thunderstorms at first. The temperature will range between 24 and 28 degrees. Moderate east to northeasterly winds, occasionally fresh over offshore waters. Marking schemes for the six weather elements: wind speed, state of sky, precipitation, visibility, maximum temperature and minimum temperature A score was given for each element An aggregate score with weighting characteristics of seasons HKO Objective Verification Scheme

16. Marking scheme State of sky CategorySunshine duration (in %) Mean cloud amount (in oktas) Overcast 07.6-8 Cloudy 0-56.1-7.5 Mainly cloudy 5.1-106.1-7.5 Mainly fine 10.1-500-6 Fine/sunny/clear >50.10-6

17. State of sky Marks Sunshine duration (%) cloudy Marking scheme of sunshine duration for the category of cloudy

18. Different weightings (in %) assigned to different weather elements at different time of the year according to climatology and the relative importance of the elements in the eye of the public WindState of skyPrecipitationVisibilityMax temperatureMin temperature January15 200 30 February10 20102030 March5530 15 April55403010 May10 60010 June201060055 July201560032 August201560032 September20 50055 October20 30015 November20 01525 December1520 01530 HKO Objective Verification Scheme

19. The score was in general on the rising trend in line with scientific advancement in weather observations, remote sensing technology, NWP and weather forecasting skills Trend of verification scores