Not sure which site you're looking at, but USGS is a little less pessimistic. See http://wa.water.usgs.gov/rt-cgi/gen_stn_pg2?station=14220500 for the Lewis and
http://wa.water.usgs.gov/rt-cgi/gen_stn_pg2?station=14243000 for the Cowlitz. Shows the Cow at about 29,000 cfs, which is high, but a little less than what you're seeing.

Main page is http://wwwdwatcm.wr.usgs.gov/realtime/rt_latest_data.html

Even though these are better, I'm still working on the house and not fishing this weekend