I was in a location where a couple of the departures from SEA were overflying me.  I happened to have the camera to hand (of course I did) and I had the polarizer on there at the time.  I had an Alaska Airlines 737 (what a shock from SEA) and a Hawaiian Airlines A330.  I grabbed a few shots.  The thing I like about the polarizer is cutting down on the glare from the white fuselages but they were still pretty bright.  The rest of the sky was darkened considerably and, when editing to address the white fuselages, even more dark.  I quite like the deep and moody look it gives to the shots with very little editing involved.  Both jets pulled some vapor as they came through the same area so clearly there was extra moisture in that one spot.  Maybe it was a thermal?