We thank C. Castro, J. E. Cole, G. McCabe, S. McAfee, J. Russell, C. Woodhouse, and J. L. Weiss for helpful comments. We also thank B. Cook, L. Wolkovitch, and the National Center for Ecological Analysis and Synthesis. This research benefited from feedback at the PACLIM 2009 Conference, with travel support provided by S. Starratt and the PACLIM 2009 organizers as well as the Institute of the Environment, University of Arizona. TA was supported by an NSF GRFP and NOAA CCDD (NA07OAR4310054), and AM was supported by the DOE GREF and SfAZ GRFP. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Abatzoglou, J. T., 2010: Influence of the PNA on declining mountain snowpack in the western United States. Int. J. Climatol., 31, 1135–1142, doi:10.1002/joc.2137.
Abatzoglou, J. T., , and K. T. Redmond, 2007: Asymmetry between trends in spring and autumn temperature and circulation regimes over western North America. Geophys. Res. Lett., 34, L18808, doi:10.1029/2007GL030891.
Betancourt, J., , M. Schwartz, , D. Breshears, , D. Cayan, , M. Dettinger, , D. Inouye, , E. Post, , and B. Reed, 2005: Implementing a U.S. National Phenology Network. Eos, Trans. Amer. Geophys. Union, 86, 51, doi:10.1029/2005EO510005.
Bonfils, C., and Coauthors, 2008: Detection and attribution of temperature changes in the mountainous western United States. J. Climate, 21, 6404–6424.
Brown, J., , S. Li, , and N. Bhagabati, 1999: Long-term trend toward earlier breeding in an American bird: A response to global warming?. Proc. Natl. Acad. Sci. USA, 96, 5565–5569.
Caprio, J. M., 1993: Western regional phenological summary of information on honeysuckle and lilac first bloom phase covering the period 1956–1991. Montana Agricultural Experiment Station State Climate Center Circular, No. 3, 92 pp.
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, 399–415.
Das, T., and Coauthors, 2009: Structure and detectability of trends in hydrological measures over the western United States. J. Hydrometeor., 10, 871–892.
de Beurs, K. M., , and G. M. Henebry, 2008: Northern annular mode effects on the land surface phenologies of northern Eurasia. J. Climate, 21, 4257–4279.
Forister, M., , and A. Shapiro, 2003: Climatic trends and advancing spring flight of butterflies in lowland California. Global Change Biol., 9, 1130–1135.
Hamlet, A. F., , P. W. Mote, , M. P. Clark, , and D. P. Lettenmaier, 2007: Twentieth-century trends in runoff, evapotranspiration, and soil moisture in the western United States. J. Climate, 20, 1468–1486.
Hidalgo, H. G., and Coauthors, 2009: Detection and attribution of streamflow timing changes to climate change in the western United States. J. Climate, 22, 3838–3855.
Inouye, D. W., 2008: Effects of climate change on phenology, frost damage, and floral abundance of montane wildflowers. Ecology, 89, 353–362.
Johnson, R. H., , P. E. Ciesielski, , B. D. McNoldy, , P. J. Rogers, , and R. K. Taft, 2007: Multiscale variability of the flow during the North American Monsoon Experiment. J. Climate, 20, 1628–1648.
Karl, T. R., , J. M. Melillo, , and T. C. Peterson, Eds., 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 188 pp.
Littell, J. S., , D. McKenzie, , D. L. Peterson, , and A. L. Westerling, 2009: Climate and wildfire area burned in western U.S. ecoprovinces, 1916–2003. Ecol. Appl., 19, 1003–1021.
McAfee, S. A., , and J. L. Russell, 2008: Northern annular mode impact on spring climate in the western United States. Geophys. Res. Lett., 35, L17701, doi:10.1029/2008GL034828.
Moore, R. D., , S. W. Fleming, , B. Menounos, , R. Wheate, , A. Fountain, , K. Stahl, , K. Holm, , and M. Jakob, 2009: Glacier change in western North America: Influences on hydrology, geomorphic hazards and water quality. Hydrol. Processes, 23, 42–61.
Mote, P., , A. Hamlet, , M. Clark, , and D. Lettenmaier, 2005: Declining mountain snowpack in western North America. Bull. Amer. Meteor. Soc., 86, 39–49.
Parmesan, C., 2006: Ecological and evolutionary responses to recent climate change. Annu. Rev. Ecol. Evol. Syst., 37, 637–669, doi:10.1146/annurev.ecolsys.37.091305.110100.
Preisendorfer, R. W., , C. D. Mobley, , and T. P. Barnett, 1988: The principal discriminant method of prediction—Theory and evaluation. J. Geophys. Res., 93, 10 815–10 830.
Qian, T. T., , A. Dai, , K. E. Trenberth, , and K. W. Oleson, 2006: Simulation of global land surface conditions from 1948 to 2004. Part I: Forcing data and evaluations. J. Hydrometeor., 7, 953–975.
Quadrelli, R., , and J. M. Wallace, 2002: Dependence of the structure of the Northern Hemisphere annular mode on the polarity of ENSO. Geophys. Res. Lett., 29, 2132, doi:10.1029/2002GL015807.
Quadrelli, R., , and J. M. Wallace, 2004: A simplified linear framework for interpreting patterns of Northern Hemisphere wintertime climate variability. J. Climate, 17, 3728–3744.
Schwartz, M. D., 1985: The advance of phenological spring across eastern and central North America. Ph.D. thesis, University of Kansas, 85 pp.
Schwartz, M. D., , and G. A. Marotz, 1986: An approach to examining regional atmosphere plant interactions with phenological data. J. Biogeogr., 13, 551–560.
Schwartz, M. D., , and T. R. Karl, 1990: Spring phenology—Nature’s experiment to detect the effect of greenup on surface maximum temperatures. Mon. Wea. Rev., 118, 883–890.
Schwartz, M. D., , G. J. Carbone, , G. L. Reighard, , and W. R. Okie, 1997: A model to predict peach phenology and maturity using meteorological variables. HortScience, 32, 213–216.
Schwartz, M. D., , R. Ahas, , and A. Aasa, 2006: Onset of spring starting earlier across the Northern Hemisphere. Global Change Biol., 12, 343–351.
Solomon, S., , D. Qin, , M. Manning, , M. Marquis, , K. Averyt, , M. M. B. Tignor, , H. L. Miller, , and Z. Chen, Eds., 2007: Climate Change 2007: The Physical Science Basis. Cambridge University Press, 996 pp.
Stenseth, N., , A. Mysterud, , G. Ottersen, , J. Hurrell, , K. Chan, , and M. Lima, 2002: Ecological effects of climate fluctuations. Science, 297, 1292–1296.
Stewart, I. T., , D. R. Cayan, , and M. D. Dettinger, 2005: Changes toward earlier streamflow timing across western North America. J. Climate, 18, 1136–1155.
Thompson, D. W. J., , and J. M. Wallace, 1998: The Arctic oscillation signature in the wintertime geopotential height and temperature fields. Geophys. Res. Lett., 25, 1297–1300.
Thompson, D. W. J., , and J. M. Wallace, 2000: Annular modes in the extratropical circulation. Part I: Month-to-month variability. J. Climate, 13, 1000–1016.
Thompson, D. W. J., , and J. M. Wallace, 2001: Regional climate impacts of the Northern Hemisphere annular mode. Science, 293, 85–89.
Thompson, D. W. J., , J. M. Wallace, , and G. C. Hegerl, 2000: Annular modes in the extratropical circulation. Part II: Trends. J. Climate, 13, 1018–1036.
Wallace, J. M., , and D. S. Gutzler, 1981: Teleconnections in the geopotential height field during the Northern Hemisphere winter. Mon. Wea. Rev., 109, 784–812.
Westerling, A. L., , H. G. Hidalgo, , D. R. Cayan, , and T. W. Swetnam, 2006: Warming and earlier spring increase western U.S. forest wildfire activity. Science, 313, 940–943.