Drought Update
September 2005 WATF Meeting
Roger A. Pielke, Sr.
Colorado Climate Center
presented at the Water Availability Task Force meeting,
Division of Wildlife, Denver, CO, September 14, 2005
Prepared by Odie Bliss
http://ccc.atmos.colostate.edu
July 2005
http://www.ncdc.noaa.gov/oa/climate/research/2005/jul/extremes.html
Colorado Average Temperatures
http://www.ncdc.noaa.gov/oa/climate/research/cag3/co.html
Colorado Total Precipitation

July 2005 Tmax

July 2005 Tmin

July 2005 Precipitation
August 2005
http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/st005dv00pcp.html
http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/st005dv00pcp.html
http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/st005dv00pcp.html
Colorado
Precipitation
Ranking
1895-2005
http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/st005dv00pcp.html
Climate divisions defined by Dr. Klaus Wolter of NOAA's
Climate Diagnostic Center in Boulder, CO
Division 1– Grand Lake 1NW
Grand Lake 1 NW
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1984
Min Year - 2002
Period of Record Average - 1941 - 2002
2005 Water Year Accumulated
35
25
20
15
10
5
Months
SE
P
G
AU
JU
L
JU
N
AY
M
AP
R
AR
M
FE
B
N
JA
EC
D
V
O
N
C
T
0
O
Accumulated Precipitation (Inches)
30
Division 1– Taylor Park
Taylor Park
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1999
Min Year - 1974
Period of Record Average - 1942 - 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
30
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 2– Collbran
Collbran 2SW
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1997
Min Year - 1974
Period of Record Average - 1893 - 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 2 – Grand Junction
Grand Junction WSFO
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1929
Min Year - 1956
Period of Record Average - 1893- 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
16
12
10
8
6
4
2
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
14
Division 3 – Montrose
Montrose #2
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1941
Min Year - 1958
Period of Record Average - 1893- 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
18
Accumulated Precipitation (Inches)
16
14
12
10
8
6
4
2
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
MAY
JUN
JUL
AUG
SEP
Division 3 – Cochetopa Creek
Cochetopa Creek
2005 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1949 - 2002
18
Max Year - 1957
Min Year - 2002
2005 Water Year
2nd Min Year - 1950
14
12
10
8
6
4
2
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
16
Division 3 – Mesa Verde
Mesa Verde NP
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1941
Min Year - 1977
Period of Record Average - 1893- 2002
2005 Water Year Accumulated
2002 Water Year
35
Accumulated Precipitation (Inches)
30
25
20
15
10
5
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
MAY
JUN
JUL
AUG
SEP
Division 4 – Del Norte
Del Norte
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1985
Min Year - 1951
Period of Record Average - 1921-2002
2005 Accumulated
2002 Accumulated Water Year
18
14
12
10
8
6
4
2
Months
SE
P
AU
G
JU
L
JU
N
AY
M
AP
R
AR
M
B
FE
JA
N
DE
C
V
NO
T
0
O
C
Accumulated Precipitation (Inches)
16
Division 4 – Center 4SSW
Center 4SSW
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1992
Min Year - 1951
Period of Record Average - 1971 - 2002
2002 Water Year
2005 Water Year
12
8
6
4
2
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
10
Division 5 – Colorado Springs
Colorado Springs
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1999
Min Year - 1939
Period of Record Average - 1893-2002
2005 Water Year Accumulated
2002 Water Year Accumulated
25
20
15
10
5
Months
P
SE
AU
G
JU
L
JU
N
AY
M
R
AP
AR
M
FE
B
JA
N
D
EC
V
N
O
C
T
0
O
Accumulated Precipitation (Inches)
30
Division 5 – Pueblo
Pueblo WSO
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1942
Min Year - 2002
Period of Record Average - 1874-2000
2005 Water Year Accumulated
20
16
14
12
10
8
6
4
2
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
18
Division 5 – Buena Vista
Buena Vista
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1965
Min Year - 1902
2005 Water Year Accumulated
Period of Record Average - 1901 - 2002
2002 Water Year Accumulated
18
14
12
10
8
6
4
2
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitaton (Inches)
16
Division 5 – Canon City
Canon City
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1957
Min Year - 1962
Period of Record Average - 1906 - 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 6 – Cheyenne Wells
Cheyenne Wells
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1909
Min Year - 1956
Period of Record Average - 1971 - 2002
2005 Water Year
2002 Water Year Accumulated
30
Accumulated Precipitation (Inches)
25
20
15
10
5
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
MAY
JUN
JUL
AUG
SEP
Division 7 – Akron
Akron 4E
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1915
Min Year - 2002
Period of Record Average - 1906 - 2002
2005 Water Year Accumulated
30
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 7 – Leroy
Leroy 5SW
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1995
Min Year - 1894
Period of Record Average - 1890-2002
2005 Water Year Accumulated
2002 Water Year Accumulated
30
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 7 – Burlington
Burlington
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1915
Min Year - 1954
Period of Record Average - 1892-2002
2005 Water Year
2002 Water Year Accumulated
35
Accumulated Precipitation (Inches)
30
25
20
15
10
5
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
MAY
JUN
JUL
AUG
SEP
Division 8 – Boulder
Boulder
2005 Water Year
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1995
Min Year - 1966
Period of Record Average - 1894-2002
2002 Water Year
35
Accumulated Precipitation (inches)
30
25
20
15
10
5
0
T
OC
V
NO
C
DE
N
JA
B
FE
AR
M
R
AP
Months
AY
M
JU
N
L
JU
AU
G
P
SE
Division 8 – Cheesman
Cheesman
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1970
Period of Record Average - 1904 - 2002
2005 Water Year
Min Year - 2002
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitaton (Inches)
25
Division 8 – Kassler
Kassler
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1915
Min Year - 1956
Period of Record Average - 1899 - 2002
2005 Water Year Accumulated
2002 Water Year Accumulated
30
20
15
10
5
Months
SE
P
G
AU
L
JU
N
JU
M
AY
AP
R
M
AR
FE
B
JA
N
EC
D
O
V
N
T
0
O
C
Accumulated Precipitation (Inches)
25
Division 8 – Fort Collins
Fort Collins
2005 Water Year
30 Year Averages-1971-2000
Max Year - 1961
Min Year - 1966
Period of Record Average - 1890 - 2002
2005 Water Year
2002 WY
30
Accumulated Precipitation (inches)
25
20
15
10
5
0
C
O
T
N
V
O
D
EC
N
JA
B
FE
AR
M
R
AP
Month
AY
M
JU
N
JU
L
AU
G
P
SE
August 2005 maximum temperatures
August 2005
Maximum
Temperature
http://www.ocs.oregonstate.edu/prism
August 2005 minimum temperatures
August 2005
Minimum
Temperature
http://www.ocs.oregonstate.edu/prism
August 2005 Average Temperatures
August 2005 precipitation
August 2005
Precipitation
http://www.ocs.oregonstate.edu/prism
WY 2005 precipitation
3 Month SPI
12 Month SPI
48 Month SPI
0.0
1890
1892
1894
1896
1898
1900
1902
1904
1906
1908
1910
1912
1914
1916
1918
1920
1922
1924
1926
1928
1930
1932
1934
1936
1938
1940
1942
1944
1946
1948
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
Fraction (in percent)
Fraction of
Colorado
in Drought
Fraction
of Colorado
in Drought
Based on 48 month SPI
(1890 - August 2005)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Year
Projected Conditions at 0.2 Probability Level
12 Month SPI at 6 months
Projected Conditions at 0.5 Probability Level
12 Month SPI at 6 months
Projected Conditions at 0.8 Probability Level
12 Month SPI at 6 months
Projected Conditions at 0.2 Probability Level
48 Month SPI at 12 months
Projected Conditions at 0.5 Probability Level
48 Month SPI at 12 months
Projected Conditions at 0.8 Probability Level
48 Month SPI at 12 months
Drought Monitor Map
July 2005 Heat Wave
Highest maximum temperature recorded in Colorado in July 2005 for
selected stations.
Colorado Springs, DIA, Grand Junction and Fort Collins daily
maximum and minimum temperatures for July 2005.
July 2005 Daily Maximum and Mininum Temperatures for Selected Stations
Colo Spr Tmax
Colo Spr Tmin
DIA Tmax
DIA Tmin
Grand Jct Tmax
Grand Jct Tmin
Ft Collins Tmax
Ft Collins Tmin
110
100
Temperature (deg F)
90
80
70
60
50
40
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Day
Denver Intl AP July 2005 Records
July 2005
New Record
Old Record
Year Last Occurred
16th
102
101
2003
19th
101
100
1934
20th
105
102
1939
21st
104
100
1981
22nd
102
100
1931
23rd
102
101
1910
Data Source: NWS F-6 form
Table 1. Average maximum, minimum and mean temperatures
for July 2005 and their rank for the period-of-record.
Table 1 continued
Table 2. Number of Days that the July 2005 maximum temperature
was greater than or equal to 90F and 100F and their rank for the
period-of-record.
Table 3. July 2005 highest maximum temperature, the rank for the period-ofrecord, the date it occurred, the highest ever July temperature and the year it
occurred, and the absolute maximum temperature and the date.
Table 3. continued
Denver’s 5-day running average if the average temperature
was greater than or equal to 83F or greater. Plotted by decade.
Denver Stapleton/City combined
5-day running average if Tave .ge. 83 deg F
86
1930s
1950s
1960s
1980s
1990s
2000s
84
Temperature (deg F)
82
80
78
76
74
1870
1890
1910
1930
1950
Year
1970
1990
2010
Edgewater and Lakewood 5-day running average for average
temperature greater than or equal to 80 deg F.
Edgewater / Lakewood
5-day running average where Tave .ge. 80 deg F
84
1940s
1950s
1960s
1970s
1980s
1990s
2000s
82
Temperature (deg F)
80
78
76
74
72
70
1940
1950
1960
1970
1980
1990
2000
2010
Fort Collins 5-day running average for average temperature greater
than or equal to 80 deg F. The Bus Transfort construction begin in
2002 next to this station.
Fort Collins
5-day running average if Tave .ge. 80 deg F
82
1920s
1930s
1950s
1960s
1970s
1990s
2000s
80
Temperature (deg F)
78
76
74
72
70
68
1920
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
Hourly data from automated weather stations at FCL and DIA are used to pick and
calculate the highest air temperature and effective temperature for each day in July 2002.
In all three months, the average high air temperature is higher at DIA, while the average
high effective temperature is higher at FCL.
Daily High T and TE -- July 2002
150
65.6
140
60.6
55.6
130
50.6
120
45.6
40.6
100
35.6
90
30.6
80
FCL T
FCL TE
DIA T
DIA TE
70
Ave
Ave
Ave
Ave
25.6
Hi T:
90.0F (32.2C)
Hi TE: 129.0F (53.9C)
Hi T:
90.7F (32.6C)
Hi TE: 125.6F (52.0C)
20.6
60
7/1
7/6
7/11
7/16
7/21
7/26
15.6
7/31
°C
°F
110
Hourly data from automated weather stations at FCL and DIA are used to pick and
calculate the highest air temperature and effective temperature for each day in July 2003.
In all three months, the average high air temperature is higher at DIA, while the average
high effective temperature is higher at FCL.
Daily High T and TE -- July 2003
150
65.6
140
60.6
55.6
130
50.6
120
45.6
40.6
100
35.6
90
30.6
80
FCL T
FCL TE
DIA T
DIA TE
70
Ave
Ave
Ave
Ave
25.6
Hi T:
90.8F (32.7C)
Hi TE: 131.6F (55.3C)
Hi T:
91.8F (33.2C)
Hi TE: 129.9F (54.4C)
20.6
60
7/1
7/6
7/11
7/16
7/21
7/26
15.6
7/31
°C
°F
110
Hourly data from automated weather stations at FCL and DIA are used to pick and
calculate the highest air temperature and effective temperature for each day in July 2005.
In all three months, the average high air temperature is higher at DIA, while the average
high effective temperature is higher at FCL.
Daily High T and TE -- July 2005
150
65.6
140
60.6
55.6
130
50.6
120
45.6
40.6
100
35.6
90
30.6
80
FCL T
FCL TE
DIA T
DIA TE
70
Ave
Ave
Ave
Ave
25.6
Hi T:
89.6F (32.0C)
Hi TE: 129.3F (54.1C)
Hi T:
93.1F (33.9C)
Hi TE: 121.4F (49.7C)
20.6
60
7/1
7/6
7/11
7/16
7/21
7/26
15.6
7/31
°C
°F
110
A daily composite of air temperature (red line) and effective temperature (blue line). The composite is created by averaging
hourly data during the five days with highest air temperature in each of the three years considered in this section – fifteen
days total. This shows the pattern of heating and cooling on the station’s extreme hottest days. Note how the effective
temperature peaks approximately four hours before the air temperature peaks. Typically, the hottest days are characterized by
exceptionally low relative humidity in the late afternoon, which explains the premature drop in effective temperature.
Composite Diurnal Cycle of T and T E
4
8
12
16
20
0
140
95
135
90
130
85
125
80
120
75
115
70
110
65
105
60
100
0
4
8
12
Local Time
16
20
0
Effective Temperature (°F)
Air Temperature (°F)
0
100
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”