Jennifer Q. Belge Eric G. Hoffman Plymouth State University

1. Preferred Regions of Convective Development over Northern New England as a Function of Flow Regime: Southwesterly Flow Case Studies http://www.eoearth.org/upload/thumb/6/61/Mature_thunderstorm_cloud.jpg/250px-Mature_thunderstorm_cloud.jpg 11/06/08 Northeast Regional Operational Workshop Jennifer Q. Belge Eric G. Hoffman Plymouth State University

2. Previous Work- Evan Lowery (2008) • 5 year climatology of northern New England thunderstorms • KGYX radar domain • April – September • 2003-2007 • SCIT • Spatial distribution of cells as a function of large-scale flow at 700 hPa

3. Results- Lowery (2008) Aroostook • NW FLOW • 3 clusters • Border of Strafford (NH) and York (ME) counties • Tri-county border of Oxford (ME), Carroll (NH) and York(ME) • Border of Grafton (NH) and Coos (NH) county • SW FLOW • 5 clusters • Central Oxford, Franklin and Somerset counties in ME • Just south of Belknap, Merrimack border in NH • Southern Oxford county in ME • Northern Grafton county in NH • Southern Somerset county in ME Piscataquis Somerset Franklin Penobscot Coos Oxford Waldo Kennebec Knox Grafton Carroll Lincoln Belknap York Sagadahoc Sullivan Androscoggin Merrimack Cumberland Cheshire Hillsborough Strafford Rockingham

4. Motivation • Lowery’s study did not address: • Why are there preferred regions of development with respect to flow regime? • Differences between flow regimes? • Forecasting potential • KGYX

5. Scientific Questions • Why do thunderstorm cells initiate where they do as a function of large-scale flow? • SW and NW @ 700 hPa only • Are there certain meteorological patterns present in the mesoscale environment that is conducive to convection in these regions found by Lowery (2008)?

6. Data and Methodology • Case Studies • Radar reflectivity examined for each case from May-September 2007 only • Case study selection • Cells were to initiate in the significant areas identified by Lowery (2008) • Cells were to not be associated with a frontal zone • Eliminate influence of frontal boundary in mesoscale analysis

7. Results • Radar • Sounding 12 UTC • KGYX • Surface analysis • RUC • Synoptic overview • 12 UTC • LAPS • KGYX • Mesoscale analysis • 17 UTC

8. July 13, 2007

10. Synoptic Analysis12 UTC

11. Surface Analysis 12 UTC

13. 500 hPa Height 12 UTC

14. 250 hPa Height and Wind 12 UTC

15. Sounding 12 UTC

16. Mesoscale Analysis17 UTC

18. Surface Analysis 18 UTC

19. Surface Dew Point 17 UTC

20. Surface CAPE 17 UTC

21. Surface Flow Vectors and Topo 17 UTC

22. Surface Flow Vectors and Topo 17 UTC

23. Surface Convergence 17 UTC

24. Mean Sea Level Pressure 17 UTC

25. Conclusions

26. Preliminary Results • July 13, 2007 SW Flow Case • Moisture & instability sufficient over entire area • Genesis region was not unique • Surface convergence and corresponding surface trough  could provide the necessary lift • Results from the August 2, 2007 case show the same results and conclusions

27. Questions? http://www.wetter-vista.de/pub/thunderstorm/cb-big.jpg WORKS CITED Lowery, E.M, 2008: Using the WSR-88D Storm Structure Product to Develop a Climatology of Northern New England Thunderstorms as a Function of Large-Scale Flow, Plymouth State University, Master of Science Thesis