Oh, I wasn't looking for an answer.  Just the fact that one herd of cows was up and one was down was funny.  Maybe there's always been a front line along the highway where I saw these cows.  OR, maybe I didn't happen to see the little barometers the cows were wearing around their necks.  ;D

The ideal time would be when the H and the L line meet on your local lake.

Ha, here in Kansas when that happens it means get the heck off the water and start looking for tornados!

I've done a good amount of research on this topic and have found that there really isn't any evidence backing the thought that barometric pressure has a direct relationship with bass.  The most common theory and in my opinion the right one is that the affects of rising/falling pressure can alter a bass' behavior but the pressure change itself cannot.  A simple example would be that a rising barometric pressure would generally lead to a sunny day and in return the "bass bite" always seems a little tougher because of a bass' tendency to shy away from the sun.  The winning ticket is to understand how the barometric pressure affects all metrological aspects of weather, and in return how those types of weather changes relate to bass.