Drought! When Do We Know It s Over?

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1 Drought! When Do We Know It s Over? Nolan J. Doesken Colorado Climate Center Colorado State University Presented at the 2004 Peak to Prairie Landscape Symposium, February 27, 2004, Colorado Springs, Colorado Prepared by Odie Bliss

2 Appreciate our climate --

3 But it s darn dry! copyrighted by Steve Hodanish

4 Colorado Springs Average Temperatures 90 Colorado Springs Average Temperatures ( ) Temperature (degrees F) Tmax Tmin Tmean Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

5 Statewide Mean Annual Temperature History

6 Colorado Average Precipitation

7 Colorado Springs Monthly Average Precipitation ( ) Colorado Springs Average Precipitation ( ) Precipitation (inches) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

8 Average Monthly Precipitation for Selected Sites Monthly Average Precipitation 3.5 Lamar Cheyenne Wells Walsh Center Fruita Rocky Ford Durango Vail 3 Precipitation (inches) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

9 Statewide Annual Precipitation History

10 Colorado Springs Precipitation Colorado Springs Precipitation History Colorado Springs Water Year Precipitation Colorado College Airport Precipitation (inches) WATER YEAR

11 Monthly Average Pan Evaporation Average Monthly Pan Evaporation for Akron and Springfield, Colorado Akron Springfield Evaporation (inches) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

12 3-Month SPI Through 1999

13 48-Month SPI Through 1999

14 The Evolution of Our Recent Drought Crystal Lakes serves Colorado Springs, Sept 2002 Seven Falls, during the 2002 drought water was pumped to top.

15 1999 Water Year Precipitation

16 2000 Water Year Precipitation

17 2001 Water Year Precipitation

18 2002 Snow Water Equivalent 60 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. 50 Wolf Creek Summit SNOTEL Inches of Water Water Year OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

19 2002 Water Year Precipitation

20 WY2002 Temperature Departures Water Year 2002 Departure from average, degree F Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys

21 2002 Daily Streamflow Colorado River near Dotsero, CO 2002 Discharge Mean Discharge Discharge (1000 CFS) OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

22 Arkansas River at Canon City Arkansas River at Canon City Streamflow History Arkansas River at Canon City Streamflow Values through Arkansas River 7-year running mean Streamflow (Cubic Ft per Second) Year

23 2003 Water Year Precipitation

24 2003 SWE Porphyry Creek

25 WY2003 Temperature Departures 10 8 Water Year 2003 Departure from average, degree F Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys

26 2003 Daily Streamflow

27 Where Do We Stand Now?

28 Water Year 2004 (Oct 03-Jan 04) Precipitation as Percent of Average

29 WY2004 (Oct 2003 Jan 2004) Temperature Departures 8 Water Year Departure from average, degree F Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys

30 Colorado Statewide Snowpack

31 Arkansas Basin Snowpack

32 Reservoir Levels Colorado Statewide Reservoir Levels on October 1st for Years and Feb 1, Percent of Average Oct Oct Oct Oct Oct Oct Oct Feb

33 What Comes Next?

34 Front Range Monthly Average Precipitation Precipitation (inches) Hoosier Pass Denver Stapleton Fort Collins Boulder Colorado Springs Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month

35 Positive Indicators Late winter snows Cool spring Multi-day precipitation Wet Snow Low intensity rainfall Light winds High humidity Abundant cloud cover

36 Negative Indicators Little late winter snow Missed opportunities Warm spring Brief, sporadic precipitation High intensity rainfall Frequent, strong winds Low humidity Abundant sunshine

37 Multivariate ENSO Index (MEI)

38 El Nino Forecast

39 Temperature March May 2004 From the Colorado Prediction Center

40 Precipitation March May 2004 From the Colorado Prediction Center

Temperature June August 2004 From the Colorado Prediction Center http://www.cpc.ncep.

41 Temperature June August 2004 From the Colorado Prediction Center

42 Precipitation June August 2004 From the Colorado Prediction Center

43 8-14 Day Temperature Forecast

44 8-14 Day Precipitation Forecast

45 Back to the Question -- When do we know it s over?

46 U.S. National Percent Area Severely U.S. National Percent Area Severely to Extremely Dry Percent of United States in Severe or Extreme Drought Percent Year

47 For Colorado Springs, Average Precipitation = ~ 17 inches Average Evaporation = ~ > 24 inches therefore, Drought is NEVER really over.

of: Temperature Humidity Wind Precipitation

48 CoAgMet Weather Data for Agriculture Automated weather stations with daily and hourly readings of: Temperature Humidity Wind Precipitation Solar energy Evapotranspiration

49 Colorado Climate Magazine Good bedtime reading about the climate of Colorado -- recent and historic $15/year subscription pays printing and mailing costs

50 Colorado Climate Center Colorado State University Data and Power Point Presentations available for downloading click on Drought then click on Presentations

Drought or Not? Nolan J. Doesken Colorado Climate Center Colorado State University

Drought or Not? Nolan J. Doesken Colorado Climate Center Colorado State University http://ccc.atmos.colostate.edu Presented at Horticultural Art Society meeting, November 19, 2004, Colorado Springs, Colorado