Same here, not just a couple ads but splattered across the pages everywhere. Smashes the readable portion of useful information down to unusable. Shows up on my hourly and 10 day forecast at least. Tried logging off and back on, didn't help.
If I have to look at ads on pages I'm uploading my own data to I'm done after many, many years of uploading to WU. I really hope this is just another glitch with WU.