1. Mike Evans NOAA/NWS Binghamton, NY Barry Lambert NOAA/NWS State College, Pa

2. Outline Motivation Methodology Climatology of inverted V events Major vs. minor events Low CAPE major vs. High CAPE major events Conclusion

3. Motivation – August 17, 2007

4. August 17, 2007 – upper air

5. August 17, 2007 - radar

6. Severe Reports 24 wind damage reports Damage was mostly trees down Damage occurred from the Finger Lakes through northeast Pa No extra staffing!

7. August 17, 2007 Albany – 00z, August 18Buffalo – 00z, August 18

8. April 8, 2010

9. April 9, 2010 00z – upper air

10. April 8, 2010 - radar

11. April 8, 2010 - Severe reports 13 wind damage reports Damage was mostly trees down Damage in southern New York through northeast Pa No extra staffing!

12. April 8, 2010 - sounding

13. Methodology Examine events from 2005-2010 Major events – 20 or more reports in New York and Pennsylvania Minor events – 1 to 4 reports in New York and Pennsylvania Identify events that occurred with inverted V soundings based on a subjective examination of 12z soundings at PIT and BUF and examination of trajectory forecasts

14. Methodology / Climatology 28 of 79 major events occurred with an upstream inverted V sounding (35 percent). 38 of 140 minor events occurred with an upstream inverted V sounding (27 percent).

15. Inverted V criteria Define a strict criteria for an inverted V sounding: - 925-800 hPa lapse rate at least 7.5 C/km - surface-800 hPa max Tdd greater than 7 C - 800-500 hPa min Tdd less than 4 C Result – 9 major events, 14 minor events.

16. Major vs. Minor Events 9 major events – 424 severe reports - 374 severe wind reports (88 percent) 14 minor events – 30 severe reports - 22 severe wind reports (73 percent)

17. Major vs. Minor Events - charts

18. Major vs. Minor Events - Charts

19. Major vs. Minor Events - composites 500 mb heights – major events500 mb heights – minor events Surface temperatures – major eventsSurface temperatures – minor events

20. Low CAPE vs. High CAPE major events - charts

21. Low CAPE vs. High CAPE major events - composites 500 mb heights – low CAPE majors 500 mb heights – high CAPE majors Surface temperatures – low CAPE majors Surface temperatures - high CAPE majors

22. Summary / Conclusion Inverted V soundings found upstream from approximately 30 percent of major and minor severe weather events Inverted V events are mostly severe wind producers Results indicate that sounding and anomaly data can be used to identify major events Forecasters should take special care to anticipate low CAPE major events