1. Advanced Shallow Weather and Orographic

2. Boundaries Thunderstorm Outflows Lake Breezes

3. Arc of blowing dust Reflectivity “thin lines” Gust Fronts Very shallow feature, emanate from a thunderstorm. Recall the depth-detection discussion.

4. Example of Boundary in Reflectivity -10 to 20 dBZ

5. Rapid Storm Evolution (Time lapse < 5 hours) Animation 120 km

6. Movie Loop Showing Cold Front, Gravity Wave and Dry Line Interactions International H 2 0 Water Vapor Project (IHOP) May 11, 2002

7. Gravity Waves International H 2 0 Water Vapor Project (IHOP) May 11, 2002

8. Drizzle

9. A Typical Z – R Beijing Summer

10. Reflectivity and Drizzle Beijing Summer

11. How to remember beamheight numbers? Aside

12. S = r θ 1 o = 180/pi = 0.0175 radians At r=100 km then s = 100 * 0.0175 S = 1.75km = beamwidth at 100km For flat Earth, for beam at 1 o elevation angle, height of beam centre ~= 1.75km H = sqrt ( r^2 + 2*Ke*ae*r + sin ( theta_e ) ) – ke * ae r s θ

13. Beam Height Diagram

14. What is the approximate Height / Width the Beam 0.5 o beamwidth1.0 o beamwidth Elevation Angle0.5 o 1.0 o 0.5 o 1.0 o Range 50 km 100 km Arc distance = r theta 1 deg = 180 / pi = 0.01745329

15. Forest Fires

16. Kelowna Forest Fires

17. Nocturnal bird migration looks like drizzle

18. Insect migration and Cb

19. Lake Breezes and Tornados Pat King and Dave Sills

20. Morning Mid Afternoon “Pure” LB example Enhance convergence Lake Breeze Boundaries Lake Huron Lake Ontario Lake St Clair Lake Erie

21. ++++ = Pure lake breeze Moderate SW Flow Lake Breezes

22. Average of 6 VIS Images from 1500-1800 UTC

23. Spring (15 Mar - 15 Jun) Tornado Touchdown Points Confirmed and probable only

24. Spring (15 Mar - 15 Jun) Tornado Touchdown Points … overlaid with boundaries from 31 July 1994... … tornadoes are suppressed in regions where Southwest winds are onshore... … and enhanced in regions where lake breeze boundaries often form. Forecasters use knowledge of lake breeze positions in their severe weather forecast for weak tornadoes

25. Lee Side Troughing On a very small terrain feature

26. Southern Ontario is relatively flat. Elevations rise from about 200m on Lake Huron to about 400m just south of Georgian Bay. Lake Huron Lake Ontario Lake Erie Georgian Bay Topography of Southern Ontario

27. Average of six GOES images over a 3-hour period Moderate WSW flow Dissipation of thin SC cloud in downslope flow SC cloud forming beneath an inversion at 1500 m above ground Dissipation of Clouds in a SW Flow

28. Topography of Southern Ontario Niagara Escarpment Average of six GOES images over a 3-hour period

29. 20 February, 2008 2008 NWA Conference - Louisville, KY Sam Lashley – National Weather Service Northern Indiana Jon Hitchcock – National Weather Service Buffalo, NY

30. Mountain Top Radars Show Rodger Brown Paper graphs

31. Negative Elevation Scans Show DEM and the one degree beam Show negative elevation angle Discuss caveats – need gc filtering Need 3dB filling Show

32. Scanning in Complex Terrain Valley Radars Show the v10 radar DEM and discuss with respect the weather NOT surveillance

33. Radar Detection Issues CAPPI (too high) 0 o PPI

34. Lake Breezes and Convection Initiation/Suppression Review the wilson boundary rules/Aurora did a poster on this Show Pat King Lake Breeze and Prevailing Wind Analysis Show Pat King Tornado climatology and Lake Breezes Show AF358 or another case

35. Lake Effect Snow Bands Show the EGPM lake effect snow bands Show single bands Show multiple bands Show the convergence in the middle of the band Talk about TREC tracking

36. Sea Spray

37. Orographic Effects Precipitation Enhancement – upslope condensation and development Precipitation Suppression –lee side troughing –Blocked flow –Radar Blockage – can not see Explanation – Impact of Froude Number