Chance of rain... 50%???

Often visitors, in anticipation of their upcoming trip to Puerto Rico, will begin to check the weather internet sites. Often they find that probabilities of rain are given for every day! Does this mean that they won't be able to be out in the sun because of rain? Will their holiday be ruined by raindrops?

Let me take a stab at this weather probability stuff for Puerto Rico. Today, Weather Underground showed a probability 50% for rain in western PR. What does this really mean? Does it mean that for half the day we will have gray skies and constant rain like one might see in the northeast US? Well, in a word, "no." It is 3pm now and all day the sky above the Lemontree has been blue with not a cloud in the sky. The radar map at 3pm, above, shows a light patch of rain in the south of Puerto Rico.

This is the tropics and during the rainy season (we have two seasons: rainy and dry) we do get rain, typically in the afternoon sometime between 2pm and 4pm. The rainfall which can be heavy or light and lasts for a only brief time and then moves off, leaves the air feeling clean and a little cooler. The rain pattern can also be patchy...believe it or not, we have seen it rain on the beach and not rain five feet away on the Lemontree! During the dry season which runs from late November to late spring or early summer, it's a very rare day when any rain appears in the sky. So the 50% chance of rain from Weather Undergound really means that somewhere in western Puerto Rico and some time in the afternoon for about a 1/2 hour there might (50% chance) be some rainfall! Whew!