Mod for top vent cap (for shielding rain)?

[J Bowie]

I can make it rain by starting a fire in my 22 WSM. I own an EZ_UP canopy but it is a pain to set up. If I get an afternoon shower, which is common in Tomball Texas, I take the lid off my Weber Master Touch and set it on top the WSM lid. So far the wind has never interfered.