1. Warm-Season Lake-/Sea-Breeze Severe Weather in the Northeast Patrick H. Wilson, Lance F. Bosart, and Daniel Keyser Department of Earth and Atmospheric Sciences, University at Albany, Albany, NY Thomas A. Wasula NOAA / National Weather Service, Albany, NY CSTAR-II Grant NA04NWS4680005 Spring CSTAR-II Meeting Presentation 4 May 2007

2. Research Goals  Investigate thermodynamic and dynamical processes along with physiographic effects  Increase awareness and understanding of this phenomenon

3. Methodology  Warm-Season: April–October  Domain area shown by the map  Selected cases from SPC archived storm data and from NWS meteorologists requests in 2000–2006  Verified from NCDC archived radar data

4. Methodology (continued)  Obtained NCEP/NARR gridded datasets for all cases to analyze important meteorological variables  Acquired 20 km-resolution RUC gridded datasets for three selected cases to perform mesoscale analyses  Collected soundings, radar data, satellite images, water temperature data, and surface observations  Classified cases into separate categories and conducted case study analyses

5. Case Classifications  Pure Case: mesoscale forcing primary; synoptic-scale forcing secondary  Mixed Case: mesoscale forcing and synoptic- scale forcing working together  Null Case: convection suppressed by lake-/sea-breeze processes

6. Case List  Pure Cases 9 August 2001 (Ontario) 6 July 2003 (Erie) 7 August 2005 (Chesapeake) 2 August 2006 (Ontario)  Mixed Cases 9 April 2001 (Erie) 19 April 2002 (Erie) 19 June 2002 (Atlantic) 24 July 2003 (Erie and Ontario) 1 August 2005 (Huron and Ontario) 5 August 2005 (Atlantic) 24 April 2006 (Chesapeake) 30 June 2006 (Erie and Ontario) 23 July 2006 (Erie and Ontario) 28 July 2006 (Atlantic)  Null Case 11 July 2006 (Atlantic)

7. Storm Formation Areas and Tracks: All Cases Legend: Red – Formation Areas Arrows – Case Tracks Green – Null Case Area Pink – Tornado Risk Area

8. SPC Verification of Cases (using convective outlook reports from 2003-2006)  Pure Cases (3) Slight Risk – 2, General Thunderstorms – 1  Mixed Cases (7) Slight Risk – 2, General Thunderstorms – 4, Nothing – 1  Null Case (1) Late Slight Risk and missed null area

9. Pure Case Example  2 August 2006 (Ontario)

10. 1200 UTC 2 August 2006 – 200 hPa Analysis 30 35 40 45 50 55 60 65 70 Pure

11. 1200 UTC 2 August 2006 – 500 hPa Analysis 14 18 22 26 30 34 38 42 46 Pure

12. 1200 UTC 2 August 2006 – Surface Analysis Pure BUF

13. 1200 UTC 2 August 2006 – Sounding http://weather.uwyo.edu/upperair/sounding.html Parcel taken from lowest 500 m to determine CAPE Pure

14. 1700 UTC 2 August 2006 – Surface Observations Pure

15. 2 August 2006 – Sea Surface Temperatures http://poet.jpl.nasa.gov Pure

16. 1700 UTC 2 August 2006 – 925 hPa Theta-E Analysis (RUC) Pure 320 325 330 335 340 345 350 355 360

17. 1800 UTC 2 August 2006 – Omega Cross-Section Analysis -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 Pure

18. 1700 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

19. 1800 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

20. 1900 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

21. 2000 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

22. 2100 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

23. 2200 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

24. 2300 UTC 2 August 2006 – Radar 70 60 50 40 30 20 10 Pure

25. 1702 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

26. 1825 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

27. 1902 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

28. 2002 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

29. 2125 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

30. 2202 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

31. 2302 UTC 2 August 2006 – Satellite http://dcdbs.ssec.wisc.edu/inventory Pure

32. 2 August 2006 – SPC Storm Reports http://www.spc.ncep.noaa.gov/climo Pure

33. Mixed Case Example  19 June 2002 (Atlantic)

34. 1200 UTC 19 June 2002 – 200 hPa Analysis 30 35 40 45 50 55 60 65 70 Mixed

35. 1200 UTC 19 June 2002 – 500 hPa Analysis 14 18 22 26 30 34 38 42 46 Mixed

36. 1200 UTC 19 June 2002 – Surface Analysis Mixed WAL

37. 1200 UTC 19 June 2002 – Sounding http://weather.uwyo.edu/upperair/sounding.html Parcel taken from lowest 500 m to determine CAPE Mixed

38. 1800 UTC 19 June 2002 – Surface Observations Mixed

39. 19 June 2002 – Sea Surface Temperatures http://poet.jpl.nasa.gov Mixed

40. 1800 UTC 19 June 2002 – 925 hPa Theta-E Analysis (RUC) Mixed 320 325 330 335 340 345 350 355 360

41. 1800 UTC 19 June 2002 – Radar 70 60 50 40 30 20 10 Mixed

42. 1900 UTC 19 June 2002 – Radar 70 60 50 40 30 20 10 Mixed

43. 2000 UTC 19 June 2002 – Radar 70 60 50 40 30 20 10 Mixed

44. 2100 UTC 19 June 2002 – Radar 70 60 50 40 30 20 10 Mixed

45. 1732 UTC 19 June 2002 – Satellite http://dcdbs.ssec.wisc.edu/inventory Mixed

46. 1902 UTC 19 June 2002 – Satellite http://dcdbs.ssec.wisc.edu/inventory Mixed

47. 2002 UTC 19 June 2002 – Satellite http://dcdbs.ssec.wisc.edu/inventory Mixed

48. 2132 UTC 19 June 2002 – Satellite http://dcdbs.ssec.wisc.edu/inventory Mixed

49. 19 June 2002 – SPC Storm Reports http://www.spc.ncep.noaa.gov/climo/ Mixed

50. Pure Case Conclusions  Ridge axis in place at the surface or aloft  Low to moderate amounts of wind shear  T > 30 ° C, T d > 20 ° C, CAPE > 1500 J kg -1  Placement and timing signal by 925 hPa θ e -ridge axis (θ e > 335 K)  Tendency to become squall lines and to prefer valleys  Intersections of boundaries enhance convection  Occur most often during hottest months of summer

51. Mixed Case Conclusions  Troughs generally in place at the surface or aloft  Mostly moderate to high wind shear  20 ° C < T < 30 ° C, 10°C < T d < 20 ° C  Placement and timing signal by 925 hPa θ e -ridge axis (320 K < θ e < 350 K)  Cyclonic vorticity and cyclonic vorticity advection important  Intersections of boundaries enhance convection  Occur most often during late spring and early autumn

52. 1800 UTC 6 July 2003 (Pure) – MODIS Satellite http://rapidfire.sci.gsfc.nasa.gov/realtime/ Questions? pwilson@atmos.albany.edu