First Alert Weather In-Depth: Connection between dew point and rainfall

ROCHESTER, N.Y. — We have had a couple of showers and thundershowers around Western New York for this Tuesday afternoon.

However, recently the rainfall has been hard to come by for most Rochesterians. And if you are a gardener, you are watering more often and even walking on your lawn you may notice the lawn has been getting a little “crunchy” from the dry conditions.

The daily rainfall amounts at the Rochester Airport over the last seven days has been almost nonexistent. It is important to note that is just one rain gauge, but there are many other communities that have measured little or no rain over the last two weeks. This lack of wet weather can be directly correlated to the dew point.

Going back in time to last Thursday, Friday, and Saturday the dew point fell to very low levels. Remember, the dew point is the temperature that air would have to be cooled to reach saturation. So the lower the dew point, the less moisture in the atmosphere.  Conversely, the higher the dew point the more moisture there is in the atmosphere.

It is probably obvious that this dry atmosphere has been changed pretty quickly as the dew point has steadily risen. The next couple of days and into the weekend the dew point will be consistently higher. This tropical air is one of the necessary ingredients for rainfall, at least for this time of the year. And that is reflected in the News 10NBC First Alert forecast that shows a higher probability of rain right into the weekend.