(September 2007 nighttime photo of beached jelly on Alki)
Thanks to Lura for sharing this info:

I’m not sure how many nature lovers are willing to brave the cold, but tonight and the next two nights have some extreme low tides. The rare clear sky and full moon means that you’ll be able to walk way, way out and see all sorts of nocturnal sea creatures – shrimp, starfish, crabs, clams…

Low tonight is -3.4 at 10:42 pm
Thursday night -3.5 at 11:27 pm, and
Friday night (early Saturday) -3.2 at 12:14.

It’s cold on the beach, but way cool.