Climate change has been occurring during the past century and trend information is a good place to start exploring potential effects and to provide the context for projections from model simulations. Locally depicted annual and seasonal trend information is available from a number of sources including those listed below:
RegClim: USGS has completed an array of high-resolution simulations of present and future climate over Western North America (WNA) and Eastern North America (ENA) by dynamically downscaling global climate simulations using a regional climate model, RegCM3.
Dominguez et al. (2012) provide an ensemble of eight dynamically downscaled simulations that are specifically useful for projecting extreme precipitation in the Western United States.
ClimateWizard.org downscaling methodologies are widely available, but are not as robust for regional and local applications as Mote and Salathé, 2010 or Salathé et al 2010 (correspondence with authors).
The model simulation results from the North American Regional Climate Change Assessment Program (NARCCAP), an international program producing high resolution regional climate change simulations. These will be used for the Northwest chapter of the 2013 National Climate Assessment, but are not yet widely available at this time.