National Park Service U.S. Department of the Interior Natural Resource Program Center Climate Monitoring in Glacier National Park: Annual Report for 2009 Natural Resource Report NPS/ROMN/NRTR—2010/388 ON THE COVER Red Eagle Lake, Glacier National Park September 2008 Photograph by: Kurt Chowanski Climate Monitoring in Glacier National Park: Annual Report for 2009 Natural Resource Report NPS/ROMN/NRTR—2010/388 Isabel W. Ashton Laura O‘Gan National Park Service Rocky Mountain Inventory & Monitoring Network 1201 Oakridge Dr, Suite 200 Fort Collins, CO 80525 Kirk Sherrill National Park Service Managed Business Solutions Inventory and Monitoring Division 1201 Oakridge Dr Fort Collins, CO 80525 October 2010 U.S. Department of the Interior National Park Service Natural Resource Program Center Fort Collins, Colorado The National Park Service, Natural Resource Program Center publishes a range of reports that address natural resource topics of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Technical Report Series is used to disseminate results of scientific studies in the physical, biological, and social sciences for both the advancement of science and the achievement of the National Park Service mission. The series provides contributors with a forum for displaying comprehensive data that are often deleted from journals because of page limitations. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols. This report received formal peer review by subject- matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This report is available from the Rocky Mountain Inventory and Monitoring Network (http://science.nature.nps.gov/im/units/romn/)and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/NRPM). Please cite this publication as: Ashton, I. W., L. O‘Gan, and K. Sherrill. 2010. Climate Monitoring in Glacier National Park: Annual Report for 2009. Natural Resource Technical Report NPS/ROMN/NRTR—2010/388. National Park Service, Fort Collins, Colorado. NPS 117/105887, October 2010 ii Contents Page Figures............................................................................................................................................ iv Tables ............................................................................................................................................. vi Executive Summary ...................................................................................................................... vii Acknowledgments........................................................................................................................ viii Introduction ..................................................................................................................................... 1 Methods........................................................................................................................................... 3 Results ............................................................................................................................................. 9 Temperature ............................................................................................................................. 9 Precipitation ........................................................................................................................... 15 Winter Snowpack ................................................................................................................... 19 Streamflow ............................................................................................................................. 19 Drought Status ....................................................................................................................... 23 Conclusions ................................................................................................................................... 26 Literature Cited ............................................................................................................................. 27 iii Figures Page Figure 1. Map showing the locations and climate zone for weather stations included in this report. .............................................................................................................................................. 4 Figure 2. Map depicting climate zones showing areas that have 0.95 or greater correlation with weather stations in each climate zone. .................................................................................... 7 Figure 3. Maps showing departures from average maximum daily temperatures for each month in calendar year 2009 versus 1971–2000. ......................................................................... 11 Figure 4. Maps showing departures from average minimum daily temperatures for each month in calendar year 2009 versus 1971–2000........................................................................... 12 Figure 5. Monthly mean minimum and maximum temperatures during 2009 for five climate zones in and around Glacier National Park. .................................................................................. 13 Figure 6. Departures of 2009 monthly mean minimum and maximum temperatures from mean temperatures for 1971-2000 for five climate zones in and around Glacier National Park. .............................................................................................................................................. 14 Figure 7. Maps showing percentiles of accumulated monthly precipitation versus 1971– 2000 for each month in calendar year 2009. ................................................................................. 16 Figure 8. Monthly and annual accumulated precipitation in 2009 for five climate zones in and around Glacier National Park.. ............................................................................................... 17 Figure 9. Monthly accumulated precipitation in 2009 as a percent of a normal period, 1971- 2000, for five climate zones in and around Glacier National Park. .............................................. 18 Figure 10. Daily measurements of snow water equivalent (SWE) and precipitation from representative sites in and near Glacier National Parks from October 2008 to September 2009............................................................................................................................................... 20 Figure 11. April 1 snow water equivalent (SWE) from SNOTEL sites in and near Glacier National Park for each year of a 15 year period from 1994-2009. ............................................. 21 Figure 12. Snow water equivalent (SWE) from watersheds in Montana on April 1, 2009 as compared to April 1 averages from the 1971–2000 period. ......................................................... 21 Figure 13. Mean daily and annual streamflow from gauges in and around Glacier National Park for the 2009 water year (October 2008 through September 2009) compared to median daily and annual mean flows from 1971-2000. ............................................................................ 22 Figure A.1. Departure of average maximum daily temperatures from 1971 – 2000 average at key climate stations in and near Glacier National Park.. .......................................................... 31 iv Figure A.2. Departure of average minimum daily temperatures from 1971 – 2000 average at key climate stations in and near Glacier National Park. ............................................................ 32 Figure A.3. Boxplots of average maximum and average minimum daily temperatures during 2009 at key climate stations in and near Glacier National Park.. ................................................. 33 Figure A.4. Departure of 2009 precipitation from 1971 – 2000 average at key climate stations in and near Glacier National Park.. .................................................................................. 34 Figure A.5. Departure of 2009 precipitation from 1991 – 2000 average at key climate stations in and near Glacier National Park.. .................................................................................. 35 v Tables Page Table 1. Weather stations in and around Glacier National Park used for the 2009 climate status report. Recent data for Browning was not available 5 Table 2. Stream gauging stations in and around Glacier National Park used for the 2009 climate status report. 6 Table 3. Climate zones in and around Glacier National Park used