Raking clouds
Bleah. Summer made a brief appearance for a couple of weeks, and now we're back in March again. 12 hours of rain, totalling .6 inch so far. At least there's no wind.
This is the weirdest picture I've ever seen in 30 years of watching radar! (Screencap from NWCN.com)
Reminds me of a cloud rake. How do those 50-mile wide ripples form?