I pay more attention to the Dew Point than I do the preasure. Up here the birds will gobble most all day long if the dew point is in the low/mid 30's. If it gets up higher in the 40's they gobble only a short time on the ground, and if the dew point is in the mid 50's they useally don't gobble on the ground, only in the roost. It kind of tells you what to expect as you head out in the morning. The birds are still there, they eat, sleep, and live in all weather, but it will give you some kind of expectation of what your going hear that morning? As the dew point raises and lowers, effects the bird on how much they are going to be gobbling that day.