Drought! When Do We Know It s Over? Nolan J. Doesken Colorado Climate Center Colorado State University http://ccc.atmos.colostate.edu Presented at the 2004 Peak to Prairie Landscape Symposium, February 27, 2004, Colorado Springs, Colorado Prepared by Odie Bliss
Appreciate our climate -- http://www.lensflare.com/~doubt/pics/garden/
But it s darn dry! http://www.crh.noaa.gov/pub/gallery/wxpics.shtml copyrighted by Steve Hodanish
Colorado Springs Average Temperatures 90 Colorado Springs Average Temperatures (1971-2000) Temperature (degrees F) 80 70 60 50 40 30 Tmax Tmin Tmean 20 10 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month
Statewide Mean Annual Temperature History
Colorado Average Precipitation
Colorado Springs Monthly Average Precipitation (1971-2000) Colorado Springs Average Precipitation (1971-2000) 4.0 3.5 Precipitation (inches) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month
Average Monthly Precipitation for Selected Sites Monthly Average Precipitation 3.5 Lamar Cheyenne Wells Walsh Center Fruita Rocky Ford Durango Vail 3 Precipitation (inches) 2.5 2 1.5 1 0.5 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month
Statewide Annual Precipitation History http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/co.html
Colorado Springs Precipitation Colorado Springs Precipitation History Colorado Springs Water Year Precipitation 30 25 20 15 10 5 5.95 0 6.79 1985 1892 1895 1898 1901 1904 1907 1910 1913 1916 1919 1922 1925 1928 1931 1934 1937 1940 1943 1946 1949 1952 1955 1958 1961 1964 1967 1970 1973 1976 1979 1982 1988 1991 1994 1997 2000 2003 Colorado College Airport Precipitation (inches) WATER YEAR
Monthly Average Pan Evaporation Average Monthly Pan Evaporation for Akron and Springfield, Colorado 14 12 Akron Springfield Evaporation (inches) 10 8 6 4 2 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month
3-Month SPI Through 1999
48-Month SPI Through 1999
The Evolution of Our Recent Drought Crystal Lakes serves Colorado Springs, Sept 2002 Seven Falls, during the 2002 drought water was pumped to top.
1999 Water Year Precipitation
2000 Water Year Precipitation
2001 Water Year Precipitation
2002 Snow Water Equivalent 60 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. 50 Wolf Creek Summit SNOTEL Inches of Water 40 30 20 Water Year 2002 10 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
2002 Water Year Precipitation
WY2002 Temperature Departures Water Year 2002 Departure from average, degree F 8 6 4 2 0-2 -4-6 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys
2002 Daily Streamflow 10000 9000 8000 Colorado River near Dotsero, CO 2002 Discharge Mean Discharge Discharge (1000 CFS) 7000 6000 5000 4000 3000 2000 1000 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
Arkansas River at Canon City Arkansas River at Canon City Streamflow History Arkansas River at Canon City Streamflow Values through 2001 1400 1200 1000 800 600 400 200 0 1890 1893 1897 1900 1903 1906 1909 1912 1915 1918 1921 1924 1927 1930 1933 1936 1939 1942 1945 1948 1951 1954 1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 Arkansas River 7-year running mean Streamflow (Cubic Ft per Second) Year
2003 Water Year Precipitation
2003 SWE Porphyry Creek
WY2003 Temperature Departures 10 8 Water Year 2003 Departure from average, degree F 6 4 2 0-2 -4-6 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys
2003 Daily Streamflow http://water.usgs.gov/cgi-bin/daily_flow?co
Where Do We Stand Now?
Water Year 2004 (Oct 03-Jan 04) Precipitation as Percent of Average
WY2004 (Oct 2003 Jan 2004) Temperature Departures 8 Water Year 2004 6 Departure from average, degree F 4 2 0-2 -4-6 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys
Colorado Statewide Snowpack http://www.co.nrcs.usda.gov/snow/data/basins.html
Arkansas Basin Snowpack http://www.co.nrcs.usda.gov/snow/data/basins.html
Reservoir Levels Colorado Statewide Reservoir Levels on October 1st for Years 1997-2003 and Feb 1, 2004 140 133 130 120 122 Percent of Average 100 80 60 40 100 93 48 74 76 20 0 Oct 1. 1997 Oct 1. 1998 Oct 1. 1999 Oct 1. 2000 Oct 1. 2001 Oct 1. 2002 Oct 1. 2003 Feb 1. 2004
What Comes Next?
Front Range Monthly Average Precipitation 4.0 3.5 3.0 Precipitation (inches) 2.5 2.0 1.5 1.0 0.5 0.0 Hoosier Pass Denver Stapleton Fort Collins Boulder Colorado Springs Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month
Positive Indicators Late winter snows Cool spring Multi-day precipitation Wet Snow Low intensity rainfall Light winds High humidity Abundant cloud cover
Negative Indicators Little late winter snow Missed opportunities Warm spring Brief, sporadic precipitation High intensity rainfall Frequent, strong winds Low humidity Abundant sunshine
Multivariate ENSO Index (MEI) http://www.cdc.noaa.gov/~kew/mei/
El Nino Forecast http://www.cdc.noaa.gov/~kew/swcasts/
Temperature March May 2004 From the Colorado Prediction Center http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.html
Precipitation March May 2004 From the Colorado Prediction Center http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.html
Temperature June August 2004 From the Colorado Prediction Center http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.html
Precipitation June August 2004 From the Colorado Prediction Center http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.html
8-14 Day Temperature Forecast http://www.cpc.ncep.noaa.gov/products/predictions/814day/
8-14 Day Precipitation Forecast http://www.cpc.ncep.noaa.gov/products/predictions/814day/
Back to the Question -- When do we know it s over?
U.S. National Percent Area Severely U.S. National Percent Area Severely to Extremely Dry Percent of United States in Severe or Extreme Drought 70 60 50 40 30 20 10 0 1900 1902 1905 1907 1910 1912 1915 1918 1920 1923 1925 1928 1931 1933 1936 1938 1941 1943 1946 1949 1951 1954 1956 1959 1962 1964 1967 1969 1972 1974 1977 1980 1982 1985 1987 1990 1993 1995 1998 2000 2003 Percent Year http://www.ncdc.noaa.gov/oa/climate/research/2004/jan/uspctarea-wetdry.txt
For Colorado Springs, Average Precipitation = ~ 17 inches Average Evaporation = ~ > 24 inches therefore, Drought is NEVER really over.
CoAgMet Weather Data for Agriculture Automated weather stations with daily and hourly readings of: Temperature Humidity Wind Precipitation Solar energy Evapotranspiration http://www.coagmet.com
Colorado Climate Magazine Good bedtime reading about the climate of Colorado -- recent and historic $15/year subscription pays printing and mailing costs http://ccc.atmos.colostate.edu/magazine.php
Colorado Climate Center Colorado State University Data and Power Point Presentations available for downloading http://ccc.atmos.colostate.edu click on Drought then click on Presentations