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A Thunderstorm Nowcasting System for the Beijing 2008 Olympics: A U.S./China Collaboration by

A Thunderstorm Nowcasting System for the Beijing 2008 Olympics: A U.S./China Collaboration by James Wilson 1 and Mingxuan Chen 2 1. National Center for Atmospheric Research, Boulder, CO 80307-3000 2. Institute of Urban Meteorology, CMA, Beijing 100089. OUTLINE.

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A Thunderstorm Nowcasting System for the Beijing 2008 Olympics: A U.S./China Collaboration by

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  1. A Thunderstorm Nowcasting System for the Beijing 2008 Olympics: A U.S./China Collaboration by James Wilson1 and Mingxuan Chen2 1. National Center for Atmospheric Research, Boulder, CO 80307-3000 2. Institute of Urban Meteorology, CMA, Beijing 100089

  2. OUTLINE • Olympics 2008 support and B08FDP • Beijing Auto-Nowcast system • Climatology • Important local considerations • Plan

  3. Convective storms frequent Beijing area • For supporting 2008 Olympics, BMB and NCAR are conducting a joint project on convective storm nowcasting that is implementation and further development of ANC at BMB

  4. Beijing 2008 Forecast Demonstration Project (B08FDP, http://www.b08fdp.org/) sanctioned by the WMO World Weather Research Program • Objective - Test state-of-the-art very short period forecasting systems Participants: • China/U.S. – Beijing Auto-Nowcast • China - GRAPES • Hong Kong – SWIRLS • Canada – CARDS • Canada/U.S. – MAPLE • U.S. – Niwot • U.S./Australia – RTFV • Australia – STEPS, TIFS

  5. B08FDP Forecast and Verification Domain 600 km 200 km 200 km 600 km • ~ 4 radars (S-band & C-band) • ~ 100 surface stations (AWS) • ~ 3 profilers • ~ 14 GPS/Met • Satellite (FY-2C & MTSAT) • ~ 3 radiosondes (4 times/day in Aug) • Meso-NWP

  6. OUTLINE • Olympics 2008 and B08FDP • Beijing Auto-Nowcast system • Climatology • Important local considerations • Plan

  7. Forecaster Input Data Sets • Radar • Satellite • Mesonet • Profiler • Sounding • Numerical • Model • Lightning Analysis Algorithms Predictor Fields Fuzzy Logic Algorithm - Membership functions - weights - Combined likelihood field Final Prediction Beijing Auto-Nowcast System

  8. Beijing Auto-Nowcast System • Produces 0-1 hr time and place specific forecast • Expert system utilizes fuzzy logic • Ingest multiple data sets • Ingest Meso-NWP outputs • 4-D Variational Doppler Radar Analysis System (VDRAS) • Extrapolates radar echoes • Forecast storm initiation, growth and dissipation • Algorithms derive forecast parameters based on the characteristics of the boundary-layer, storms, and clouds

  9. Initiation nowcasts Extrapolation nowcasts Example of Auto-Nowcast 60-min Initiation Forecast 1 hour forecast Verification

  10. OUTLINE • Olympics 2008 and B08FDP • Beijing Auto-Nowcast system • Climatology • Important local considerations • Plan

  11. 9 cases northeast 4 cases north 17% of total 28 cases northwest 77% of total 11 cases west 20 cases southwest 6% of total 3 cases southeast 2 cases south • Distribution of storm initiation or appearance location over Beijing area • Based on 2003~2005 data from Beijing C-band radar (77 cases and > 30 dBZ) Conclusion: Most (77%) of those come from a westerly direction

  12. 4(2) 9(7) 28(10) 0 2(2) 11(4) 3(2) 20(7) 2(1) • Origin of storms (>30 dBZ) that arrive in or initiate in Beijing area • Based on 2003~2005 data from Beijing C-band radar (79 cases and > 30 dBZ) • inside bracket number storms initiatiated in Beijing • Conclusions: • 57% move in and 43% initiate • 28% of those that move in enhance

  13. OUTLINE • Olympics 2008 and B08FDP • Beijing Auto-Nowcast system • Climatology • Important local considerations • Plan

  14. Important local considerations for the Beijing Auto-nowcast system • Terrain and southeast winds • Convection initiation along convergence lines • Sea breeze influences • Dissipation or enhancement as storms move from mountains to plains • Dissipation of storms when convergence line moves away

  15. Example 1: Terrain influence with southeast low-level flow

  16. Example 1: Terrain influence with southeast low-level flow

  17. Example 2: Squall line dissipation moving from mountain to plains Click to start or pause animation

  18. Example 3: Squall line enhancement moving from mountain to plains Click to start or pause animation

  19. Example 5: Boundary running away from storm and dissipating Click to start or pause animation

  20. Example 6: Initiation and enhancement of storms when boundaries interact and storms move from mountains to plain/urban areas

  21. Example 6: Initiation and enhancement of storms when boundaries interact and storms move from mountains to plain/urban areas

  22. Example 6: Initiation and enhancement of storms when boundaries interact and storms move from mountains to plain/urban areas Click to start or pause animation

  23. OUTLINE • Olympics 2008 and B08FDP • Beijing Auto-Nowcast system • Climatology • Important local considerations • Plan

  24. Plan • Ingesting of new local data (Zhangbei C-band radar, AWS surrounding Beijing, FY-2C, profiler, etc.) • Further development and improvement of the nowcast system • Rerun some 2006 cases • Tune parameters and memberships • Add some new algorithms • Radar climatology study • Trial demonstration summer 2007 • Formal FDP in 2008

  25. Thank you for your attention!

  26. Example 4: Storm initiation by convergence lines, rolls also play role Click to start or pause animation

  27. Example 6: Initiation and enhancement of storms when boundaries interact and storms move from mountains to plain/urban areas

  28. Three S-band Radar Mosaic (Beijing, Tianjin and Shijiazhuang)06/27/2006 1820UTC

  29. Diurnal Cycle based on Tianjin radar Echo Frequency >35 dBZ Minimum over Beijing 1-2 a.m. local Maximum 6-7 p.m. local

  30. 30min fcst (08/01/2006 0916UTC) 60min fcst (08/01/2006 0844UTC) Ref (08/01/2006 0947UTC) 60min fcst (08/01/2006 0844UTC) growth steady decay initiation

  31. The monthly number of related synoptic system with storms Jun Jul Aug Trough Subtropical high Cold vortex

  32. The percent of related steering wind with storms 500 mb 700 mb 850 mb No data

  33. Rainstorm Thunderstorm Total hailstorm Gale • Frequency distribution of convective weather phenomena in Beijing area • Based on surface observations in 5-9 month of 12 years (1994-2005)

  34. The percent of related synoptic system with storms Subtropical high Trough Cold vortex

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