With the horrible season we experienced in Washington State last year, I was looking around at many different areas for information on snow conditions, avalanche danger and weather forecasts. Below is a list of sites that I have found to be useful. It is far from complete, so shoot me an email if you know of a site that has good information.
Idaho
Weather Forecast: National Weather Service - Sawtooth Mountains
Weather & Avalanche Forecast: Idaho Avalanche Center - Idaho Panhandle Avalanche Center
Avalanche Forecast: Idaho Avalanche Center - Sawtooth National Forest Avalanche Center
Avalanche Forecast: Idaho Avalanche Center - Payette Avalanche Center
Oregon
Weather Forecast: National Weather Service - North Oregon Cascades
Weather Forecast: National Weather Service - South Central Oregon Cascades
Weather Forecast: National Weather Service - South Oregon Cascades and Siskiyou Mountains
Avalanche Forecast: NWAC - Olympics, Washington Cascades & Mount Hood
Utah
Weather Forecast: National Weather Service - Cottonwood Canyons
Weather Forecast: National Weather Service - Provo Canyons
Weather Forecast: National Weather Service - Cottonwood Canyon 7 Day Digital Forecast
Avalanche Advisory: Utah Avalanche Center - Wasatch Range
Washington State
Weather Forecast: National Weather Service - West Slopes Northern Cascades and Passes
Weather Forecast: National Weather Service - West Slopes Central Cascades and Passes
Weather Forecast: National Weather Service - South Washington Cascades Range
Weather Forecast: National Weather Service - East Slopes Northern Cascades
Weather Forecast: National Weather Service - East Slopes of the Southern Washington Cascades
Weather Forecast: NWAC - Olympics, Washington Cascades & Mount Hood
Avalanche Forecast: NWAC - Olympics, Washington Cascades & Mount Hood
General Site : Turns All Year - complete list of telemetry, forecasts, radar and more