1. Alberta Broadcasters Public Alerting Recognition Symposium Meteorological Decision Making Image Courtesy Steve Ricketts

2. Outline Alberta Summer Weather Weather Centre Operations Severe Weather Meteorologist Convective warnings Decision Making Process

3. Photo Courtesy Justin Hobson Elie Manitoba June 22, 2007

4. Alberta Convective Climate

5. Annual Alberta Svr Weather Events YearHailWindTornadoRainTotal 200056915181 20014476360 20021243120 20037019141104 2004521715690 20056869487 2006831454106 20078937128146 Average 481211879

6. Weather Centre Operations PASPC Responsible for Public and Marine Forecasts & Warnings Edmonton & Winnipeg split the Responsibility Each office 2.4 people shifts, 24hrs per day, 365 days per year Automation leveraged Co located with Aviation forecast centre – CMAC in Edmonton Graphic Courtesy McCarthy 2007

7. Equivalent Areas of Responsibility Graphics Courtesy McCarthy

8. Means for Dissemination Weatheroffice web site. Most popular Web site in gc.ca domain… Specialized media site WeatherRadio ATADs Media Partners EPWS Warning Lead time for supercells/tornados is critical

9. Weather Radio Network in Alberta

10. Severe Weather Meteorologist Supervisor on shift Analysis/Diagnosis/Pr ognosis Highly trained Convective weather Radar interpretation Decision making Phases of shift Workup-anticipation Weather watch Heat of battle Bulletins Thunderstorm Watches/warnings Tornado Watches/warnings

11. Radar Critical and sophisticated tool Spirit River, Jimmy Lake Carvel, Strathmore, Schuler Measures hydrometeor intensity and radial motions Detects rotating storms (Supercells) but not tornadoes Ground reports critical for tornadoes Doppler coverage of southern and central Alberta is not continuous

12. Decision Making Information Analysis of temp, wind and moisture NWP guidance Radar and satellite –Monitor boundaries Lightning detection Soundings including aircraft Weather watchers Thunderstorm Options Watches - When to issue? Where? Type to issue? Thunderstorm Warnings – When? Where? Difference between a Watch and a Warning? Tornado warnings On busy days numerous bulletins can be in effect Photo copyright Neil Taylor

13. Decision Making EPWS Always Issue for Dangerous Supercells Tornado warnings require SPC to trigger EPWS Most effective way to deliver message Nerve racking task Practice is key Info includes storm/tornado location and motion Preset Forms Unusually strong Supercell Possible tornado (rotation detected within doppler range) Tornado on ground

14. Conclusion Weather Radio fills an important gap in our dissemination process because said radios can sleep until a programmed watch or warning id is received EPWS decisions add to the work load of the forecast team However, within Environment Canadas dissemination network there is no better means to quickly disseminate life threatening severe weather situations than the EPWS

17. Copyrighted and courtesy of Brad McLeod

18. Why do we activate EPWS?