The infared radar measures the temperture of the cloud tops and is often not a good indicator of where precip is happening. Ground radar is much better for determining locations and intensity of precip.

Infared satelites loops and images come from NASA GOES satelites. Many websites use the GOES satalite info. Ground radar are in fixed locations and you are at the limitations of where they exist.

My favarite weather sites:

http://www.wunderground.com/cgi-bin/findweather/hdfForecast?query=seattle%2C+wa&searchType=WEATHER

http://www.ghcc.msfc.nasa.gov/GOES/

http://www.cira.colostate.edu/cira/RAMM/Rmsdsol/main.html