A Review of the 2007 Water Year in Colorado Nolan Doesken Colorado Climate Center, CSU Mike Gillespie Snow Survey Division, USDA, NRCS Presented at the 28 th Annual AGU Hydrology Days, March 26, 2008, Colorado State University, Fort Collins, CO (Prepared by Odie Bliss) http://ccc.atmos.colostate.edu http://www.co.nrcs.usda.gov/snow/
Where did it all start? 2006 Water Year Precipitation 2
Drought Monitor 3
Highlights of the 2007 Water Year in Colorado Photo courtesy Rich Keen, Coal Creek Canyon, December 2006 4
WY 2007 Summary Wet October 2006 December 2006 Snowstorms Persisting snowcover and cold (Eastern Plains) Holly tornado March 28, 2007 Early snowmelt and dry May 2007 Hot summer with spotty storms September rains especially West Slope 5
Colorado Snowcover As of January 7, 2007 http://rapidfire.sci.gsfc.nasa.gov/subsets/?aeronet_bsrn_bao_boulder 6
Colorado Snowcover As of February 15, 2007 http://rapidfire.sci.gsfc.nasa.gov/subsets/?aeronet_bsrn_bao_boulder 7
Water in the Snowpack during early February and the Total Precipitation for the months of December and January Yellow - water equivalent measured by coring/melting as reported by Cooperative Observers Light Blue - water equivalent measured by coring/weighing as reported by NWS employees Boxed - total precipitation for December and January as reported by Cooperative Observers http://www.crh.noaa.gov/crnews/display_story.php?wfo=pub&storyid=5870&source=0 8
A Very Bad Day Holly Tornado March 28, 2007 9
WY2007 Temperature Summary Cold October 2006 across the state November/December above or near average January and February cold, especially Eastern Plains (near -10 deg F departure) March above average statewide April 2007 cold Eastern Plains, average Foothills, warmer Mountains and Western Valleys Near average all across the state for May Above average temperatures for June through September for most of the state 10
Water Year 2007 temperature departures from 1971-2000 average 8.0 Water Year 2007 Temperature Departures Temperature Departure (deg F) 6.0 4.0 2.0 0.0-2.0-4.0-6.0-8.0-10.0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Eastern Plains Foothills Mountains Western Valleys 11
Water Year Winter (Dec Feb) Statewide Temperature History 12
2007 Water Year Temperatures for Colorado Most recent 12-month period (Oct 2006 Sep 2007) (Period of record 1895 2007) 13
Colorado Snowpack for 2007 Good Start, Early Finish COLORADO SNOWPACK Summary for 2007 USDA Natural Resources Conservation Service JANUARY FEBRUARY MARCH APRIL MAY JUNE 140 130 120 110 100 % OF AVERAGE 90 80 70 60 50 40 30 20 10 0 Gunnison Colorado S. Platte N. Platte Yampa-White Arkansas Rio Grande San Juan* State *Includes Animas, Dolores, San Miguel Basins
Wolf Creek Summit Snotel 60 SNOW WATER EQUIV. PRECIPITATION AVEAGE SWE AVERAGE PRECIP. Inches of Water 50 40 30 20 Wolf Creek Summit SNOTEL Water Year 2007 10 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 15
Mesa Lakes Snotel 40 35 30 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. Mesa Lakes SNOTEL Inches of Water 25 20 15 10 Water Year 2007 5 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 16
Hoosier Pass Snotel Inches of Water 35 30 25 20 15 10 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. Hoosier Pass SNOTEL Water Year 2007 5 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
Berthoud Summit Snotel 45 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. 40 35 Berthoud Summit SNOTEL Inches of Water 30 25 20 15 Water Year 2007 10 5 0 OCT OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 18
Joe Wright Snotel 50 45 SNOW WATER EQUIV. PRECIPITATION AVERAGE SWE AVERAGE PRECIP. Inches of Water 40 35 30 25 20 15 10 5 Joe Wright SNOTEL Water Year 2007 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
April 1 Snowpack http://www.co.nrcs.usda.gov/snow/snow/state/current/monthly/maps_graphs/getsnomap.html
April 1 Snowpack History APRIL 1 SNOWPACK COLORADO STATEWIDE 160 148 146 Percent of Average 140 120 100 80 60 130 126 119 109 109 104 106 99 95 87 46 59 120 114 127 104104 97 85 87 74 91 93 126 84 105 112 114 89 65 90 87 52 94 65 107 94 75 40 20 0 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 Year
Winter (Oct 2006 Apr 2007) % of Average 22
Summer 2007 (May Sep) precipitation as a percent of average (Prism) 23
Daily Precipitation Accumulation Summer 2007 (May-September) for Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) Precipitation (inches) 16 14 12 10 8 6 4 CoCoRAHS Accumulated Precipitation for Summer (May-Sep) by County Baca County Fremont County Park County Montezuma County Weld County Phillips County 2 0 5/1/2007 6/1/2007 7/2/2007 8/2/2007 9/2/2007 24
Water Year 2007 precipitation as a percent of average (Prism) 25
Colorado Precipitation in Historic Perspective Most recent 12-month period (Oct 2006 Sep 2007) (Period of record 1895 2007) 26
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Animas River Streamflow 8000 7000 Animas River at Durango, CO 2007 Discharge Mean Discharge Discharge, (1000 CFS) 6000 5000 4000 3000 2000 1000 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
Colorado River Streamflow 10,000 9,000 8,000 Colorado River near Dotsero, CO 2007 Discharge Mean Discharge Discharge (1000 CFS) 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
Cache La Poudre River Streamflow 3000 Cache La Poudre River at Mouth of Canyon 2500 Mean Discharge 2007 Discharge Discharge, (1000 CFS) 2000 1500 1000 500 0 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
Poudre Streamflow vs. Average Streamflow vs. Average 900 800 2007 Average 700 600 500 400 300 200 Acre Feet (Thousands) 100 0 Rio Grande Purgatoire Eagle Taylor Animas Yampa
2007 Reservoir Storage Summary Reservoir storage improved across the state even with lack of snowpack and runoff Volumes tracked above average for most of the year in Gunnison, Colorado and San Juan/Animas/Dolores and San Miguel basins Storage statewide declined to 98% of average on September 30
Reservoir Storage by Basin, Oct 1, 2007 120 October 1, 2007 100 Percent of Average 80 60 40 20 0 Statewide Gunnison Colorado South Platte Arkansas Rio Grande San Juan* *includes the Animas and Dolores basins
Colorado Reservoir Storage Levels Colorado Statewide Reservoir Levels on October 1st for Years 1997-2007 140 120 100 80 60 40 20 0 34 Percent of Average Oct 1. 1997 Oct 1. 1998 Oct 1. 1999 Oct 1. 2000 Oct 1. 2001 Oct 1. 2002 Oct 1. 2003 Oct 1. 2004 Oct 1. 2005 Oct 1. 2006 Oct 1. 2007
CoCoRaHS Community Collaborative Rain Hail and Snow: We re looking for more volunteers!
CoCo RaHS Daily Highlights 2007 Water Year October 26, 2006 36
October 27, 2006 37
December 21, 2006 38
April 24, 2007 39
April 25, 2007 40
June 12, 2007 41
June 13, 2007 42
July 20, 2007 43
August 3, 2007 44
September 23, 2007 45
September 24, 2007
Natural Resources Conservation Service Snow Survey Office Access to snowpack, precipitation, reservoir data and streamflow forecast information available at: http://www.co.nrcs.usda.gov/snow/index.html
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