The last couple years I’ve been taking to gouache as the plein aire medium of choice. It’s quite versatile, quick to setup and easy to work with small. Very portable and dries evenly. The palettes that I’m using still need some modification though. Haven’t found the perfect setup for that yet. But the color choices are great. Bold pure colors much like my oil setups.
On Gray days when the light is diffused it’s actually a good time to paint in wide-open areas to get the feel of the light. Also, painting man-made light sources are a good way to judge the light and dark and to make your paintings come alive. Either way, there’s a lot of great opportunities no matter what the weather conditions hold.
You just have to get out there and commit yourselves. 🙂