I always believed in barametric pressure playin' a large part in my success! I have found that if the weather is stable for three or more days the bite is moderate to good, but as soon as a thunder head is rollin in, and a pressure drop begins the fish go into lunch mode and awesome fishing begins!
This could be 20 minutes or even a full day of hot action depending on season.
After the rain is gone and the storm leaves, the pressure climbs the fish get "lockjaw" or inactive.
I have found that these changes in barometric pressure effect fish more in the summer and fall then winter and spring.
Rich