1. Long-term Precipitation Trends in Colorado Nolan Doesken Colorado State Climatologist Presented: Friday, December 12, 2008

2. Colorado Mean Annual Precipitation (1971-2000)

3. Of All Our Climate Observing Stations

4. Colorado Statewide Water Year (Oct-Sept) Precipitation

5. Only a Few Have Excellent Long-Term Records

6. Best Long Term Precipitation Time Series

7. Fort Collins

8. Kassler

9. Byers

10. Grand Lake 1NW

11. Grand Lake 6SSW

12. Hayden

13. Montrose #2

14. Cochetopa Creek

15. Mesa Verde

16. Del Norte

17. Trinidad City

18. Cheyenne Wells

19. Rocky Ford

20. Akron 4E

21. What is normal precipitation and how does it relate to the recent past?

22. Fort Collins

23. Kassler

24. Byers

25. Grand Lake 1NW

26. Grand Lake 6SSW

27. Hayden

28. Montrose #2

29. Cochetopa Creek

30. Mesa Verde

31. Del Norte

32. Trinidad City

33. Cheyenne Wells

34. Rocky Ford

35. Akron 4E

36. Colorado Snotel Sites Assessment of long term April 1 st SWE provides information on long term winter precipitation trends.

37. University Camp (10,300’)

38. Dry Lake (8,400’)

39. Independence Pass (10,600’)

40. Porphyry Creek (10,760’)

41. Upper San Juan (10,200’)

42. What is the frequency of drought?

46. Tracking Evapotranspiration

47. Seasonal (May-Sept.) Alfalfa Reference ET Tracking and understanding ET trends allows for more efficient water use planning

48. Seasonal Reference ET Time Series

50. CoAgMet and NCWCD CoAgMet’s results were compared to a similar weather network in Northern Colorado The Northern Colorado Water Conservancy District (NCWCD) weather station network is a “gold standard” for ET comparison due to their high standards for siting, maintenance, and calibration

51. NCWCD versus CoAgMet: North Central Region

52. NCWCD and CoAgMet: Lower South Platte Region

53. Coming Soon: Climate Trends Website http://climatetrends.colostate.edu Access Colorado long-term station data and station history Generate and download graph images Customizable data frequency for graphing (monthly, water year, calendar year, etc)