Warming is Driving Decreases in Snow Fractions While Runoff Efficiency Remains Mostly Unchanged in Snow-Covered Areas of the Western United States

Gregory J. McCabe U.S. Geological Survey, Denver, Colorado

Search for other papers by Gregory J. McCabe in
Current site
Google Scholar
PubMed
Close
,
David M. Wolock U.S. Geological Survey, Lawrence, Kansas

Search for other papers by David M. Wolock in
Current site
Google Scholar
PubMed
Close
, and
Melissa Valentin U.S. Geological Survey, Denver, Colorado

Search for other papers by Melissa Valentin in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Winter snowfall and accumulation is an important component of the surface water supply in the western United States. In these areas, increasing winter temperatures T associated with global warming can influence the amount of winter precipitation P that falls as snow S. In this study we examine long-term trends in the fraction of winter P that falls as S (Sfrac) for 175 hydrologic units (HUs) in snow-covered areas of the western United States for the period 1951–2014. Because S is a substantial contributor to runoff R across most of the western United States, we also examine long-term trends in water-year runoff efficiency [computed as water-year R/water-year P (Reff)] for the same 175 HUs. In that most S records are short in length, we use model-simulated S and R from a monthly water balance model. Results for Sfrac indicate long-term negative trends for most of the 175 HUs, with negative trends for 139 (~79%) of the HUs being statistically significant at a 95% confidence level (p = 0.05). Additionally, results indicate that the long-term negative trends in Sfrac have been largely driven by increases in T. In contrast, time series of Reff for the 175 HUs indicate a mix of positive and negative long-term trends, with few trends being statistically significant (at p = 0.05). Although there has been a notable shift in the timing of R to earlier in the year for most HUs, there have not been substantial decreases in water-year R for the 175 HUs.

For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Gregory J. McCabe, gmccabe@usgs.gov

Abstract

Winter snowfall and accumulation is an important component of the surface water supply in the western United States. In these areas, increasing winter temperatures T associated with global warming can influence the amount of winter precipitation P that falls as snow S. In this study we examine long-term trends in the fraction of winter P that falls as S (Sfrac) for 175 hydrologic units (HUs) in snow-covered areas of the western United States for the period 1951–2014. Because S is a substantial contributor to runoff R across most of the western United States, we also examine long-term trends in water-year runoff efficiency [computed as water-year R/water-year P (Reff)] for the same 175 HUs. In that most S records are short in length, we use model-simulated S and R from a monthly water balance model. Results for Sfrac indicate long-term negative trends for most of the 175 HUs, with negative trends for 139 (~79%) of the HUs being statistically significant at a 95% confidence level (p = 0.05). Additionally, results indicate that the long-term negative trends in Sfrac have been largely driven by increases in T. In contrast, time series of Reff for the 175 HUs indicate a mix of positive and negative long-term trends, with few trends being statistically significant (at p = 0.05). Although there has been a notable shift in the timing of R to earlier in the year for most HUs, there have not been substantial decreases in water-year R for the 175 HUs.

For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Gregory J. McCabe, gmccabe@usgs.gov
Save
  • Abatzoglou, J. T., 2011: Influence of the PNA on declining mountain snowpack in the western United States. Int. J. Climatol., 31, 11351142, https://doi.org/10.1002/joc.2137.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Aguado, E., D. R. Cayan, L. G. Riddle, and M. Roos, 1992: Climatic fluctuations and the timing of West Coast streamflow. J. Climate, 5, 14681483, https://doi.org/10.1175/1520-0442(1992)005<1468:CFATTO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bamzai, A. S., 2003: Relationship between snow cover variability and Arctic Oscillation index on a hierarchy of time scales. Int. J. Climatol., 23, 131142, https://doi.org/10.1002/joc.854.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Berghuijs, W. R., R. A. Woods, and M. Hrachowitz, 2014: A precipitation shift from snow towards rain leads to a decrease in streamflow. Nat. Climate Change, 4, 583586, https://doi.org/10.1038/nclimate2246.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bohr, G. S., and E. Aguado, 2001: The use of April 1 SWE measurements as estimates of peak seasonal snowpack and total cold season precipitation. Water Resour. Res., 37, 5160, https://doi.org/10.1029/2000WR900256.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Brown, R. D., 2000: Northern Hemisphere snow cover variability and change, 1915–1997. J. Climate, 13, 23392355, https://doi.org/10.1175/1520-0442(2000)013<2339:NHSCVA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cayan, D. R., S. A. Kammerdiener, M. D. Dettinger, J. M. Caprio, and D. H. Peterson, 2001: Changes in the onset of spring in the western United States. Bull. Amer. Meteor. Soc., 82, 399415, https://doi.org/10.1175/1520-0477(2001)082<0399:CITOOS>2.3.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Clark, M. P., M. C. Serreze, and G. J. McCabe, 2001: The historical effect of El Niño and La Niña events on the seasonal evolution of the montane snowpack in the Columbia and Colorado River basins. Water Resour. Res., 37, 741757, https://doi.org/10.1029/2000WR900305.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Clow, D. W., 2010: Changes in the timing of snowmelt and streamflow in Colorado: A response to recent warming. J. Climate, 23, 22932306, https://doi.org/10.1175/2009JCLI2951.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Déry, S. J., and R. D. Brown, 2007: Recent Northern Hemisphere snow cover extent trends and implications for the snow-albedo feedback. Geophys. Res. Lett., 34, L22504, https://doi.org/10.1029/2007GL031474.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dettinger, M. D., and D. R. Cayan, 1995: Large-scale atmospheric forcing of recent trends toward early snowmelt in California. J. Climate, 8, 606623, https://doi.org/10.1175/1520-0442(1995)008<0606:LSAFOR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Falcone, J. A., D. M. Carlisle, D. M. Wolock, and M. R. Meador, 2010: GAGES: A stream gage database for evaluating natural and altered flow conditions in the conterminous United States. Ecology, 91, 621, https://doi.org/10.1890/09-0889.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Feng, S., and Q. Hu, 2007: Changes in winter snowfall/precipitation ratio in the contiguous United States. J. Geophys. Res., 112, D15109, https://doi.org/10.1029/2007JD008397.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ficklin, D. L., I. T. Stewart, and E. P. Maurer, 2013: Effects of climate change on stream temperature, dissolved oxygen, and sediment concentration in the Sierra Nevada in California. Water Resour. Res., 49, 27652782, https://doi.org/10.1002/wrcr.20248.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Frans, C., E. Istanbulluoglu, V. Mishra, F. Munoz-Arriola, and D.P. Lettenmaier, 2013: Are climatic or land cover changes the dominant cause of runoff trends, in the Upper Mississippi River Basin? Geophys. Res. Lett., 40, 11041110, https://doi.org/10.1002/grl.50262.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Frei, A., and D. A. Robinson, 1999: Northern Hemisphere snow extent: Regional variability 1972–1994. Int. J. Climatol., 19, 15351560, https://doi.org/10.1002/(SICI)1097-0088(19991130)19:14<1535::AID-JOC438>3.0.CO;2-J.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Frei, A., D. A. Robinson, and M. G. Hughes, 1999: North American snow extent: 1900–1994. Int. J. Climatol., 19, 15171534, https://doi.org/10.1002/(SICI)1097-0088(19991130)19:14<1517::AID-JOC437>3.0.CO;2-I.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Garbrecht, J., M. Van Kiew, and G. O. Brown, 2004: Trends in precipitation, streamflow, and evapotranspiration in the Great Plains of the United States. J. Hydrol. Eng., 9, 360367, https://doi.org/10.1061/(ASCE)1084-0699(2004)9:5(360).

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gibson, W. P., C. Daly, T. Kittel, D. Nychka, C. Johns, N. Rosenbloom, A. McNab, and G. Taylor, 2002: Development of a 103-year high-resolution climate data set for the conterminous United States. 13th Conf. on Applied Climatology, Portland, OR, Amer. Meteor. Soc., 7.2, https://ams.confex.com/ams/13ac10av/techprogram/paper_41347.htm.

  • Gleick, P. H., 1987: Regional hydrologic consequences of increases in atmospheric carbon dioxide and other trace gases. Climatic Change, 10, 137161, https://doi.org/10.1007/BF00140252.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gleick, P. H., and D. B. Adams, 2000: Water: The potential consequences of climate variability and change for the water resources of the United States. Water Sector Assessment Team Rep., Pacific Institute for Studies in Development, Environment, and Security, 151 pp., http://pacinst.org/wp-content/uploads/2013/02/natl_assessment_water3.pdf.

  • Gupta, S. C., A. C. Kessler, M. K. Brown, and F. Zvomuya, 2015: Climate and agricultural land use change impacts on streamflow in the upper Midwestern United States. Water Resour. Res., 51, 53015317, https://doi.org/10.1002/2015WR017323.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hamlet, A. F., P. W. Mote, M. P. Clark, and D. P. Lettenmaier, 2005: Effects of temperature and precipitation variability on snowpack trends in the western United States. J. Climate, 18, 45454561, https://doi.org/10.1175/JCLI3538.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Helsel, D. R., and L. M. Frans, 2006: Regional Kendall test for trend. Environ. Sci. Technol., 40, 40664073, https://doi.org/10.1021/es051650b.

  • Hirsch, R. M., J. R. Slack, and R. A. Smith, 1982: Techniques of trend analysis for monthly water quality data. Water Resour. Res., 18, 107121, https://doi.org/10.1029/WR018i001p00107.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Huntington, T. G., G. A. Hodgkins, B. D. Keim, and R. W. Dudley, 2004: Changes in the proportion of precipitation occurring as snow in New England (1949–2000). J. Climate, 17, 26262636, https://doi.org/10.1175/1520-0442(2004)017<2626:CITPOP>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knowles, N., M. D. Dettinger, and D. R. Cayan, 2006: Trends in snowfall versus rainfall in the western United States. J. Climate, 19, 45454559, https://doi.org/10.1175/JCLI3850.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lehner, F., E. R. Wahl, A. W. Wood, D. B. Blatchford, and D. Llewellyn, 2017: Assessing recent declines in Upper Rio Grande runoff efficiency from a paleoclimate perspective. Geophys. Res. Lett., 44, 41244133, https://doi.org/10.1002/2017GL073253.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. R. Legates, 1995: Relationships between 400 hPa height anomalies and 1 April snowpack accumulations in the western USA. Int. J. Climatol., 15, 517530, https://doi.org/10.1002/joc.3370150504.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. M. Wolock, 1999: Future snowpack conditions in the western United States derived from general circulation model climate simulations. J. Amer. Water Resour. Assoc., 35, 14731484, https://doi.org/10.1111/j.1752-1688.1999.tb04231.x.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and M. P. Clark, 2005: Trends and variability in snowmelt runoff in the western United States. J. Hydrometeor., 6, 476482, https://doi.org/10.1175/JHM428.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. M. Wolock, 2009: Recent declines in western U.S. snowpack in the context of twentieth-century climate variability. Earth Interact., 13, https://doi.org/10.1175/2009EI283.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. M. Wolock, 2010: Long-term variability in Northern Hemisphere snow cover and associations with warmer winters. Climatic Change, 99, 141153, https://doi.org/10.1007/s10584-009-9675-2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. M. Wolock, 2011: Independent effects of temperature and precipitation on modeled runoff in the conterminous United States. Water Resour. Res., 47, W11522, https://doi.org/10.1029/2011WR010630.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., and D. M. Wolock, 2016: Variability and trends in runoff efficiency in the conterminous United States. J. Amer. Water Resour. Assoc., 52, 10461055, https://doi.org/10.1111/1752-1688.12431.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., M. P. Clark, and L. E. Hay, 2007: Rain-on-snow events in the western United States. Bull. Amer. Meteor. Soc., 88, 319328, https://doi.org/10.1175/BAMS-88-3-319.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCabe, G. J., D. M. Wolock, G. T. Pederson, C. A. Woodhouse, and S. McAfee, 2017: Evidence that recent warming is reducing upper Colorado River flows. Earth Interact., 21, https://doi.org/10.1175/EI-D-17-0007.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mote, P. W., A. F. Hamlet, M. P. Clark, and D. P. Lettenmaier, 2005: Declining mountain snowpack in western North America. Bull. Amer. Meteor. Soc., 86, 3949, https://doi.org/10.1175/BAMS-86-1-39.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nowak, K., M. Hoerling, B. Rajagopalan, and E. Zagona, 2012: Colorado River basin hydroclimatic variability. J. Climate, 25, 43894403, https://doi.org/10.1175/JCLI-D-11-00406.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Press, W. H., B. P. Flannery, S. A. Teukolsky, and W. T. Vetterling, 1986: Numerical Recipes. Cambridge University Press, 848 pp.

  • Rajagopalan, B., and U. Lall, 1995: Seasonality of precipitation along a meridian in the western United States. Geophys. Res. Lett., 22, 10811084, https://doi.org/10.1029/95GL01100.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Regonda, S. K., B. Rajagopalan, M. Clark, and J. Pitlick, 2005: Seasonal cycle shifts in hydroclimatology over the western United States. J. Climate, 18, 372384, https://doi.org/10.1175/JCLI-3272.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rex, D. F., 1950: Blocking action in the middle troposphere and its effect upon regional climate. Tellus, 2, 196211, https://doi.org/10.1111/j.2153-3490.1950.tb00331.x.

    • Search Google Scholar
    • Export Citation
  • Schilling, K. E., M. J. Manjo, Y.-K. Zhang, P. W. Gassman, and C. F. Wolter, 2008: Impact of land use and land cover change on the water-balance of a large agricultural watershed: Historical effects. Water Resour. Res., 44, W00A09, https://doi.org/10.1029/2007WR006644.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schottler, S. P., J. Ulrich, P. Belmont, R. Moore, J. W. Lauer, D. R. Engstrom, and J. E. Almendinger, 2014: Twentieth century agricultural drainage creates more erosive rivers. Hydrol. Processes, 28, 19511961, https://doi.org/10.1002/hyp.9738.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Serreze, M. C., M. P. Clark, R. L. Armstrong, D. A. McGinnis, and R. L. Pulwarty, 1999: Characteristics of the western U.S. snowpack from snowpack telemetry (SNOTEL) data. Water Resour. Res., 35, 21452160, https://doi.org/10.1029/1999WR900090.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stewart, I. T., D. R. Cayan, and M. D. Dettinger, 2004: Changes in snowmelt runoff timing in western North America under a ‘business as usual’ climate scenario. Climatic Change, 62, 217232, https://doi.org/10.1023/B:CLIM.0000013702.22656.e8.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tomer, M. D., and K. E. Schilling, 2009: A simple approach to distinguish land-use and climate-change effects on watershed hydrology. J. Hydrol., 376, 2433, https://doi.org/10.1016/j.jhydrol.2009.07.029.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wolock, D. M., and G. J. McCabe, 2018: Water-balance model inputs and outputs for the conterminous United States, 1900–2015. USGS, accessed 2 May 2016, https://doi.org/10.5066/F71V5CWN.

    • Crossref
    • Export Citation
  • Xu, X., B. R. Scanlon, K. Schilling, and A. Sun, 2013: Relative importance of climate and land surface changes on hydrologic changes in the US Midwest since the 1930s: Implications for biofuel production. J. Hydrol., 497, 110120, https://doi.org/10.1016/j.jhydrol.2013.05.041.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1219 576 13
PDF Downloads 710 185 4