Climate Perspective
Nolan Doesken
State Climatologist
Colorado Climate Center
Atmospheric Science Department
Colorado State University
http://ccc.atmos.colostate.edu
Presented at Colorado Conservation Tillage Association
Greeley, CO, February 3-4, 2009
Prepared by Wendy Ryan
Colorado Average Annual Precipitation Map
Precipitation: Annual Climatology (1971-2000)
Average Wheat-Season Precipitation
September – June (Inches)
(Based on 1961-90 observed data)
Average May-June Precipitation (Inches) (Based
on 1961-90 observed data)
Average Precipitation (Inches)
For the Period 15 July – 25 August
(Based on 1961-1990 observed data)
Average Monthly Precipitation along the I-70
Corridor
Water Year Average Precipitation for Selected Stations in the I-70 Transect
Loveland Pass
Georgetown
Ralston Resvr
Denver
Byers
Burlington
Limon
4.5
4.0
Precipitation (inches)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Monthly Average Precipitation in NE Agricultural Areas
Average Monthly Precipitation for NE Colorado Agricultural Areas
4
LONGMONT 2 ESE
GREELEY UNC
STERLING
HOLYOKE
3.5
Precipitation (in)
3
2.5
2
1.5
1
0.5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Akron 8 year average (2001-2008) vs. 30 year Normal (1971-2000)
3.50
Average
Normal
3.00
Precip (in)
2.50
2.00
1.50
1.00
0.50
0.00
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Greeley 8 year average (2001-2008) vs. 30 year Normal (1971-2000)
3.00
Average
Normal
2.50
Precip (in)
2.00
1.50
1.00
0.50
0.00
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Holyoke 8 year average (2001-2008) vs. 30 year Normal (1971-2000)
4.00
Average
Normal
3.50
3.00
Precip (in)
2.50
2.00
1.50
1.00
0.50
0.00
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Highlights of the 2008 Water Year
in Colorado
Status at beginning of 2008
Water Year
Drought Monitor October 2, 2007
D0
Abnormally Dry
D1 Drought Moderate
D2 Drought Severe
D3 Drought –
Extreme
D4 Drought Exceptional
Highlights of Water Year 2008
• Autumn: Mild and quite dry
• Winter: Cold with heavy
mountain snows
• Spring: Cool with generous
snowmelt runoff
• Windsor Tornado May 22, 2008
• Drought expanded on the plains
–July very hot
• Wet August, especially Eastern
Plains
Windsor Tornado May 22nd, 2008
•One mile wide at times!
•One fatality and 15 - 20 injuries.
•FEMA estimates 850 homes damaged.
•Privately insured damages total 147 million
dollars.
•Poudre Valley REA reported 1 million dollars of
damage to electric transmission facilities.
Information and Map thanks to
NWS-BOU
A closer look at the Climate
of the 2008 Water Year in
Colorado
Water Year 2008 Temperature Departures
from 1971-2000
Water Year 2008average
Temperature Departure (deg F)
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
Oct
Nov
Eastern Plains
Dec
Jan
Feb
Foothills
Mar
Apr
May
Mountains
Jun
Jul
Aug
Sep
Western Valleys
Kersey CoAgMet Temperatures
Month by Month Precipitation
2008 Accumulated Precipitation Comparison
Yuma and Elbert Cocorahs Station 2008 Precipitation Comparison
30
CO-YU-59 (near Kirk)
25
Accumulated Precipitation (in)
CO-EL-12 (near Limon)
20
15
10
5
0
11/14/2007
1/3/2008
2/22/2008
4/12/2008
6/1/2008
7/21/2008
Date
9/9/2008
10/29/2008
12/18/2008
2/6/2009
Cheyenne
Wells Water Year
Cheyenne Wells
2008
2008 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1971 - 2002
2008 Water Year
Max _Precip
MAY
JUL
Min precip
30
Accumulated Precipitation (Inches)
25
20
15
10
5
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
JUN
AUG
SEP
Akron 2008 Water Year
Akron 4E
2008 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1906 - 2002
2008 Water Year Accumulated
Max Precip
Min Precip
Year of Max
30
20
15
10
5
Months
SE
P
G
A
U
L
JU
N
JU
Y
A
M
PR
A
R
A
M
FE
B
JA
N
D
EC
O
N
C
T
V
0
O
Accumulated Precipitation (Inches)
25
Akron 4E 2008 CY Daily Precipitation
Akron 4E 2008 Daily Accumulated Precipitation (in)
Accumulated Precipitation (in)
20
18
Accumulated Precipitation (in)
16
Accumulated Normal
14
12
10
8
6
4
2
0
11/14/2007
1/3/2008
2/22/2008
4/12/2008
6/1/2008
7/21/2008
Date
9/9/2008
10/29/2008
12/18/2008
2/6/2009
Fort Collins
Fort Collins
2008 Water Year
2008 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1890 - 2002
2008 Water Year
Max Precip
Min Precip
30
Accumulated Precipitation (inches)
25
20
15
10
5
0
O
CT
NO
V
C
DE
N
JA
B
FE
M
AR
R
AP
Month
AY
M
N
JU
L
JU
G
AU
P
SE
Rocky Ford
2008
Rocky
Ford Water Year
2008 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1889-2002
2008 Water Year Accumulated
Max Precip
min Precip
20
15
10
5
Months
SE
P
G
A
U
L
JU
JU
N
Y
A
M
PR
A
R
A
M
FE
B
N
JA
EC
D
V
O
N
C
T
0
O
Accumulated Precipitation (Inches)
25
Drought Monitor
0.0
Year
2007
2005
2002
2000
1997
1995
1992
1990
1987
1985
1982
1980
1977
1975
1972
1970
1967
1965
1962
1960
1957
1955
1952
1950
1947
1945
1942
1940
1937
1935
1932
1930
1927
1925
1922
1920
1917
1915
1912
1910
1907
1905
1902
1900
1897
1895
1892
1890
Fraction (in percent)
Fraction of Colorado in Drought
Based on 48 month SPI
(1890 - August 2008)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Water Year 2009
October – December 2008
Water Year 2009 Temperature Departures
from
1971-2000
Normals
Water
Year 2009
Temperature Departure (deg F)
7.0
5.0
3.0
1.0
-1.0
-3.0
-5.0
Oct
Nov
Eastern Plains
Dec
Jan
Feb
Foothills
Mar
Apr
May
Mountains
Jun
Jul
Aug
Sep
Western Valleys
Nov 2008 Temperature Departure
Dec 2007 Temperature
Departures???
Fort Collins WY2009
Fort Collins
2009 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1890 - 2002
2009 Water Year
Max Precip
Min Precip
30
Accumulated Precipitation (inches)
25
20
15
10
5
0
O
CT
NO
V
C
DE
N
JA
B
FE
AR
M
R
AP
Month
AY
M
N
JU
L
JU
G
AU
P
SE
Boulder WY2009
Boulder
2009 Water Year
2009 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1894-2002
Max Precip
Min Precip
35
Accumulated Precipitation (inches)
30
25
20
15
10
5
0
O
CT
NO
V
C
DE
N
JA
B
FE
M
AR
R
AP
Months
AY
M
N
JU
L
JU
AU
G
P
SE
Akron 4E
Akron
WY2009
2009 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1906 - 2002
2009 Water Year Accumulated
Max Precip
Min Precip
Year of Max
30
20
15
10
5
Months
SE
P
G
A
U
L
JU
N
JU
Y
A
M
PR
A
R
A
M
FE
B
N
JA
EC
D
O
N
C
T
V
0
O
Accumulated Precipitation (Inches)
25
Cheyenne Wells WY2009
Cheyenne Wells
2009 Water Year
30 Year Averages-1971-2000
Period of Record Average - 1971 - 2002
2009 Water Year
Max _Precip
MAY
JUL
Min precip
30
Accumulated Precipitation (Inches)
25
20
15
10
5
0
OCT
NOV
DEC
JAN
FEB
MAR
APR
Months
JUN
AUG
SEP
Joe Wright Snotel
Kersey CoAgMet
Holyoke CoAgMet
Center CoAgMet
Water Year 2009
What’s
Lies
Ahead
What’s Lies Ahead
MEI and SST
Experimental CDC
“Forecast Guidance”
http://www.cdc.noaa.gov/people/klaus.wolter/SWcasts/
FMA Temperature
FMA Precipitation
MAM Temperature
MAM Precipitation
JJA Temperature
JJA Precipitation
SON Temperature
SON Precipitation
Colorado Winter (Dec-Feb) Temperatures
Winter (Dec-Feb) 1896 - 2008 Data
2010
Winter (DJF) Eastern Plains Precipitation
Winter Precipitation (in)
3.5
Akron Winter
Holyoke Winter
Cheyenne Wells Winter
Byers Winter
3
Winter Precipitation (in)
2.5
2
1.5
1
0.5
0
1920
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
2020
Colorado Spring (Mar-May) Temperatures
Spring (Mar-May) 1895 - 2008 Data
2010
Spring (MAM) Eastern Plains Precipitation
Spring Precipitation (in)
16
14
Akron Spring
Holyoke Spring
Cheyenne Wells Spring
Byers Spring
Spring Precipitation (in)
12
10
8
6
4
2
0
1920
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
2020
Colorado Summer (Jun-Aug) Temperatures
Summer (Jun-Aug) 1895 - 2008 Data
2010
Summer (JJA) Eastern Plains Precipitation
Summer Precipitation (in)
18
16
Akron Summer
Holyoke Summer
Cheyenne Wells Summer
Byers Summer
Summer Precipitation (in)
14
12
10
8
6
4
2
0
1920
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
2020
Colorado Fall (Sep-Nov) Temperatures
Fall (Sep-Nov) 1895 - 2008 Data
2010
Fall (SON) Eastern Plains Precipitation
Fall Precipitation (in)
9
Akron Fall
Holyoke Fall
8
Cheyenne Wells Fall
Byers Fall
7
Fall Precipitation (in)
6
5
4
3
2
1
0
1920
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
2020
Colorado Precipitation in Historic Perspective
(Period of record 1895 – 2008)
2010
www.coagmet.com
And How About CoCoRaHS?
• Hundreds of new observers,
especially from other states
Hail Map 5/22/08
Precipitation 5/23/08
Precipitation 5/27/08
Weld County 6/5/08
Precipitation 8/7/08
Weld County 8/7/08
Precipitation 8/16/08
Weld County 8/16/08
There is great need for sub-county scale
precipitation information for drought
assessment
Official NOAA-NWS surface networks typically provide
1-4 observing sites per county
– This is good for long term monitoring
-- This is less good for drought monitoring
-- We would like to increase this X10
How many volunteers do we need?
• Our goal is at least one per square mile
over urban/suburban areas.
• One per 36 square miles over rural areas.
Is your square mile covered?
• If not, please sign up to help
measure rain, hail and snow
from your backyard
• If so, sign up anyway 
• http://www.cocorahs.org
and click on “Join CoCoRaHS”
For More Information, Visit the
CoCoRaHS Web Site
http://www.cocorahs.org
Support for this project provided by
NSF Informal Science Education Program,
NOAA Environmental Literacy Program
and
many local charter sponsors.
Colorado Climate Center
Data and Power Point Presentations
available for downloading
http://ccc.atmos.colostate.edu
click on “Drought”
– then click on “Presentations”
–