1. Linking Synoptic Climatology to Hydrologic Responses in Upstate New York and Western New England Created by: David Thomas, University at Albany, SUNY A COMET project between the University at Albany, SUNY and National Weather Service Forecast Office, Albany N.Y. February 2003

2. Location of Stations 625 COOP stations from New York State and adjoining counties were used. Time Frame: 1951 – 2000 November through April

3. Elevation of Region

4. Albany

5. Rochester

6. Definition of Wind Direction: A forecast 6 Day mean 200 hPa wind with wind direction as follows: WSW = 236.25 - 258.74 West = 258.75 - 281.24 WNW = 281.25 - 303.74

7. Definition of Snow Depth Change For a particular event a COOP station was considered only if it had a snow depth loss, or no change in snow depth. Any snow depth gains were eliminated from the list. If more than 25% of the COOP stations had a snow gain for a particular event, that event was not included in the study.

8. Definition of Rain on Snow Rainfall is defined as at least 0.10 inches of rain over a given day. In the event of mixed precipitation a 10:1 liquid water equivalent assumption was made to estimate how much precipitation fell strictly as rain.

9. Statistics for Snow Depth Change

10. Statistics for Rain on Snow

11. Albany wind: west-southwest

13. Albany wind: west

15. Albany wind: west-northwest

17. Rochester wind: west-southwest

19. Rochester wind: west

21. Rochester wind: west-northwest

23. Cumulative Frequency Charts Based on the 277 events for Albany, New York and 365 events for Rochester, New York, that had 0.50 inches or more of 6 day SWE loss. Based on WSW,West, and WNW wind direction. Not all events had a 2 day rainfall.

24. Albany Rain on Snow Cumulative Frequency

25. Rochester Rain on Snow Cumulative Frequency

26. Albany Rain on Snow wind: west-southwest

28. Albany Rain on Snow wind: west

30. Albany Rain on Snow wind: west-northwest

32. Rochester Rain on Snow wind: west-southwest

34. Rochester Rain on Snow wind: west

36. Rochester Rain on Snow wind: west-northwest