My current favorite: windy.com. Set it to "NAM3km," pick the overlay you want to see, and press the "play" button...

• NOAA Forecast, Yreka, CA
• Dark Sky
• Intellicast - Interactive Weather Map
• Real-Time Lightning
  LightningMaps.org
• Real-Time U.S. Composite Satellite Image -- SSEC
  Space Science and Engineering Center, University of Wisconsin-Madison
• SSEC Geostationary Satellite Images
• WunderMap, by Weather Underground
• Department of Water Resources, California Data Exchange Center - Reservoirs
• Current California Streamflow Conditions, USGS