Prioritise safety first
If gusts become strong, rain is heavy, or lightning is possible, stop cooking outside. Do not drag the BBQ into a garage, porch, tent, or kitchen doorway.
Protect the food
Move cooked food indoors, keep raw food chilled, and finish partly cooked items in the oven or under the grill. This is not failure. This is catering with plot development.
The oven backup is not the enemy. The enemy is pretending sideways rain is ambience.