When using a sling psycho meter what would you notice about the wet and dry bulbs that would tell you that it is probably going to rain?

When using a sling psychrometer, if the difference between the dry bulb and wet bulb temperatures is small, it indicates high humidity levels. This high humidity suggests that the air is saturated with moisture, which often precedes rain. Additionally, if the wet bulb temperature is close to or at the dry bulb temperature, it further supports the likelihood of impending precipitation.