Do storms influence the souring of dishes?
The short answer is no, storms don't cause souring.  Souring occurs because of bacterial or yeast growth.  Sometimes this is desirable, sometimes not, depending on your goals.  If by "souring" you mean spoilage, proper sanitation and refrigeration are your best protections.  Sometimes the composition of a food container can impact the flavor of foods (tin and acidic dishes, for example).  That is why there are often instructions to use non-reactive containers. However, this has nothing to do with the weather.  Of course, ambient conditions, such as extremes in humidity or temperature, can impact the cooking process, when baking, for example...but storms don't accelerate or influence spoilage.