Big stopper

The weather of yesterday afternoon: Clouds and windy. I like it when there is turmoil in the air. Ideal circumstances to experiment with long exposure times (91 seconds in the photo below, Lee big stopper filter used).

* Canon EOS 5D Mark II, 17-40mm/f4 @ 17 mm; ISO-200, f16, 91s; 2 stop ND hard gradient filter; tripod.