Drought Perspectives
Nolan Doesken and Roger Pielke, Sr.
Colorado Climate Center
Prepared by Tara Green and Odie Bliss
http://climate.atmos.colostate.edu
Fort Collins Summer Average Temperature
(June - August)
74
72
70
Temperature (Deg. F)
68
66
64
62
Summer Total
60
7 year running mean
58
56
19
19
19
19
19
19
19
19
19
19
18
18
99
89
79
69
59
49
39
29
19
09
99
89
Years
18
90
18
95
19
00
19
05
19
10
19
15
19
20
19
25
19
30
19
35
19
40
19
45
19
50
19
55
19
60
19
65
19
70
19
75
19
80
19
85
19
90
19
95
20
00
Precipitation (inches)
Fort Collins Historic Precipitation
35
30
25
20
15
10
5
0
Month
1890 through 2002
1960-2002
20
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
18
18
00
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
05
00
95
90
Sedgewick 5S Historic Precipitation
35
30
25
20
15
10
5
0
18
9
18 0
9
18 4
9
19 8
0
19 2
0
19 6
1
19 0
1
19 4
1
19 8
2
19 2
2
19 6
3
19 0
3
19 4
3
19 8
4
19 2
4
19 6
5
19 0
5
19 4
5
19 8
6
19 2
6
19 6
7
19 0
7
19 4
7
19 8
8
19 2
8
19 6
9
19 0
9
19 4
9
20 8
02
Grand Lake 1NW Historic Precipitation
35
30
25
20
15
10
5
0
1941-2002
Through 1999
Through 1999
Reservoir Storage
Statewide Reservoir Levels for Colorado
140
Percent of Average
120
100
80
60
40
20
0
Oct 1. 1998
Oct 1. 1999
Oct 1. 2000
Oct 1. 2001
Oct 1. 2002
Feb 1. 2003
Date
Provisional Data Provided by NRCS
What Comes Next?
Fort Collins Accumulated Deficit
for October 1997 through March 2003
10
8
Inches
6
4
2
0
-2
-4
-6
8
9
0
1
2
3
7
8
9
0
1
2
3
8
9
0
1
2
3
-9 b-9 n-9 t-9 b-9 n-9 t-9 b-0 n-0 t-0 b-0 n-0 t-0 b-0 n-0 t-0 b-0 n-0 t-0
t
c
c
c
c
c
c
c
O Fe Ju O Fe Ju O Fe Ju O Fe Ju O Fe Ju O Fe Ju O
Month
Year
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
1940
1935
1930
1925
1920
1915
1910
1905
1900
1895
1890
Precipitation (inches)
Fort Collins
Accumulated Precipitation Deficit
(Average 1890-2002)
20
10
0
-10
-20
-30
-40
Monthly Average Precipitation for Selected Sites
in the South Platte Basin
4
Hoosier Pass
4
Denver Stapleton
Sterling
Precipitation (inches)
3
3
2
2
1
1
0
t
Oc
v
No
c
De
Ja
n
Fe
b
ar
M
r
Ap
Month
ay
M
Ju
n
Ju
l
g
Au
Se
p
Monthly Average Precipitation for Selected Sites
in the South Platte Basin
4
3.5
Greeley
Fort Morgan
2.5
Sterling
2
Julesburg
1.5
1
0.5
Months
em
be
r
Se
pt
ug
us
t
A
Ju
ly
Ju
ne
ay
M
pr
il
A
ar
ch
M
Fe
br
ua
ry
y
Ja
nu
ar
ec
em
be
r
D
ov
em
be
r
N
ct
ob
er
0
O
Precipitation (Inches)
3
What Happens Next
• We have never experienced 2 consecutive
extreme statewide drought years.
• Past multi-year drought, characterized by
one extreme year preceded and followed by
other dry year.
• Entire Region rarely all recovers quickly and
at the same time.
• Hope for the best, plan for the worst!!
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
Joe Wright Water Year
Snotel 2002
NWCC: http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=CO
Joe Wright Water Year
Snotel 2003
NWCC: http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=CO
Bear Lake Water Year
Snotel 2002
NWCC: http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=CO
Bear Lake Water Year
Snotel 2003
NWCC: http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=CO
Lake Irene Water Year
Snotel 2002
NWCC: http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=CO
Lake Irene Water Year
Snotel 2003
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 Center
Colorado State University
• Data and Power Point Presentations available
for downloading
• http://climate.atmos.colostate.edu
click on “Drought”
then click on “Presentations”
CoCo RaHS
YOU CAN HELP!
http://www.cocorahs.com