It's a good thing oldtimers like me are around to set you youngsters straight!
All - that *all* - the cows have to be lying down for the forecast to be rain! Three or four of five or 10 of 12 doesn't count. *And* if you look carefully, and if they are all facing in the same direction, you can tell the storm is coming from the direction *opposite to where there heads are. IOW they put their (ahem) flanks to the wind.