UNSTABLE The UNderstanding Severe Thunderstorms and Alberta Boundary Layers Experiment Neil Taylor 1, Dave Sills 2, John Hanesiak 3, Jason Milbrandt 4 1 Hydrometeorology and Arctic Lab, Environment Canada (EC) 2 Cloud Physics and Severe Weather Research Section, EC 3 Centre for Earth Observation Science, University of Manitoba 4 NWP Research Section, EC Project Overview 41 st Annual CMOS Congress St. John’s Newfoundland

June 2, st CMOS Congress – St. John’s 2 Outline Rationale UNSTABLE Goals and Science Questions Experimental Design Project Status Summary

June 2, st CMOS Congress – St. John’s 3 Rationale: Socio-economic Impacts Alberta Foothills experience more lightning days than anywhere else on the Canadian Prairies Burrows (2007, personal communication)

June 2, st CMOS Congress – St. John’s 4 Rationale: Socio-economic Impacts Edmonton – Calgary corridor one of most densely populated regions in Canada and contains Canada’s 3 rd (YYC) and 7 th (YEG) busiest airports Statistics Canada (2007)

June 2, st CMOS Congress – St. John’s 5 Rationale: Socio-economic Impacts Edmonton – Calgary corridor among fastest growing regions in Canada Statistics Canada (2007)

June 2, st CMOS Congress – St. John’s 6 Rationale: Socio-economic Impacts Frequent (Severe) Thunderstorms + People + More People + Busy Airports = Potential Human and Economic Loss Since 1980 > $2B and > 40 lives lost in AB due to severe thunderstorms Improved understanding of processes leading to severe storms  better warnings  mitigate impacts of severe weather on Canadians

June 2, st CMOS Congress – St. John’s 7 Rationale: AB Severe Wx Forecast Challenges Forecasters face uncertainty with respect to: ABL structure and evolution (especially vertical water vapour profiles in ABL) Role and importance of mesoscale boundaries / circulations in foothills (dryline?) Land surface – ABL interactions (sensible / latent heat fluxes) in foothills and upstream Conceptual models for CI Compounded by: Inadequate observation network to resolve the above NWP performance with respect to above

June 2, st CMOS Congress – St. John’s 8 Large void of real-time surface observations over the Alberta foothills Foothills a known genesis region for severe thunderstorms Rationale: Obs. Network Hourly SFC observations available to PASPC forecasters

June 2, st CMOS Congress – St. John’s 9 UNSTABLE Goals To improve understanding of atmospheric processes (especially in ABL) prior to and during CI and severe thunderstorm development To improve accuracy and lead time for severe thunderstorm watches and warnings To assess utility of GEM-LAM-2.5 to resolve physical processes over AB Foothills and ability to provide useful guidance for CI and severe thunderstorm forecasts To refine existing conceptual models describing CI and severe thunderstorm development over AB and the Western Prairies

June 2, st CMOS Congress – St. John’s 10 UNSTABLE Science Questions ABL Processes (Taylor/Sills – Environment Canada [EC]) 1.What are the contributions of ABL processes to the initiation of deep moist convection and the development of severe thunderstorms in the Alberta Foothills? –ABL moisture, convergence boundaries and associated circulations Land Surface – ABL Interactions (Hanesiak – U of Manitoba) 2. What are the contributions of surface processes to the initiation of deep moist convection and the development of severe thunderstorms in the Alberta Foothills? –Soil moisture and mesoscale circulations, heat fluxes Numerical Weather Prediction (Milbrandt – EC) 3. To what extent can high-resolution NWP models contribute to forecasting the initiation and development of severe thunderstorms originating in the Alberta Foothills?

June 2, st CMOS Congress – St. John’s 11 What is Needed to Resolve ABL and Other Processes Related to CI? Mobile SFC Aircraft Soundings Profilers Tethersonde Fixed Mesonet N

June 2, st CMOS Congress – St. John’s 12 Targeted Instrumentation Fixed Mesonet stations (10-20) 2 radiosondes Tethersonde 2 WV radiometers Profiling radiometer (H 2 O profile) GPS PW sensors Eddy Correlation Flux Tower(s)? Additional Profiling Radiometer (T, RH)? Mobile AMMOS / Strong Mobile (T, P, RH) MARS (PW, SFC wx, profile – wind, T, RH) 3 radiosondes Aircraft Photography Locations of fixed radiometers, GPS sensors, tethersonde to be determined 15 Station Configuration 19 Station Configuration

June 2, st CMOS Congress – St. John’s 13 Experimental Design: Duration and IOP UNSTABLE Study Period 1 June to 31 August 2008 Fixed mesonet stations to be deployed prior to June 1st 2008 Mobile instrumentation / communications tests in 15 June to 31 June window Intensive Observation Period Tentatively 9 July to 31 July (23 days) contingent on field participation, expendables,…

June 2, st CMOS Congress – St. John’s 14 UNSTABLE Project Status Test of mesonet instrumentation summer 2006 Preliminary mesonet site selections last fall – further scouting this summer / fall Stockpiling radiosondes (currently 273) Science questions and plan drafted External UNSTABLE website at: /unstable/ First UNSTABLE science workshop held April in Edmonton Science Plan being finalized and submitted for internal and external funding Mesonet instrumentation currently being deployed for BAQS-Met in Southern Ontario UNSTABLE Field Operations Plan to be drafted Fall/Winter with workshop to follow

June 2, st CMOS Congress – St. John’s 15 Collaborators UNSTABLE is a collaborative project with National and Provincial Government, Canadian University, and Private Sector participation

June 2, st CMOS Congress – St. John’s 16 Summary Potential for future human and economic loss in Alberta due summer severe storms is increasing Accuracy and lead-time of convective watches and warnings need to be maximized to mitigate impacts of summer severe weather Field experiment being designed to investigate ABL processes significant for CI and severe storm development over the Alberta foothills (summer 2008) Efforts to transfer results to SPC operations with aim to improve watches / warnings (e.g., RSD) UNSTABLE to include both observational and modeling components –targeted, high-resolution fixed and mobile surface and upper-air observations –2.5 km configuration of CMC GEM LAM Science questions and plan drafted – in process of refining science questions and instrumentation / measurement strategies

June 2, st CMOS Congress – St. John’s 17 Thank You! (780)