SW-NCA-color-FINALweb

100 assessment of climate change in the southwest united statesEndnotesi Tables 5.1 and 5.2 present temperature and precipitation conditions for the first decade of thetwenty-first century, respectively, and compare those conditions against 100-year averages of theprevious century. Shown also are the rankings of the recent decadal conditions relative to the tendecades of the twentieth century, both for the Southwest as a whole and for the six individualstates comprising the region. The tables assess average temperature, maximum temperature,minimum temperature, and precipitation. The data are based on the monthly PRISM analysis(Daly 2006) which incorporates physiographic features (e.g., complex topography and coastalzones) in the process of generating climate grids from available in situ data, the consequence ofwhich is to substantially improve analyses in the Western United States relative to other climateanalyses (Daly et al. 2008).ii Data used in Tables 5.1 and 5.2 are based on 2.5 mile (4km) resolution PRISM analyses (data availableat: http://www.prism.oregonstate.edu/products/matrix.phtml?view=data). For purposes oflong period trend estimates, we present diagnoses conducted at station locations, rather thanfrom gridded data, and examine those sites that possess historical observations spanning most ofthe 1901–2010 period.iii The trends were calculated at station locations based on Global Historical Climate Network(GHCN) Version 3 (Menne and Williams 2009; data available at http://www.ncdc.noaa.gov/ghcnm/v3.php).iv Another measure of heat and cold waves is discussed in Chapter 7, Sections 7.2 and 7.3.v Drought is defined here as having at least a -1 (or lower) PDSI intensity.vi These included the Southwest as well as drainage basins in the Cascades, Blue Mountains ofOregon, and the northern Rockies of Idaho and Montana.vii Analysis of a subset of the Cook et al. dataset, covering only the Southwest region, shows DAIvariability across the Southwest over the last 1,200 years to be very similar to that across thelarger area depicted in Figure 5.7.