Study of 2010 monthly rainfall rates and comparison with significant precipitation events in Puerto Rico

Puerto Rico is a tropical island located in the Caribbean, the smallest of the Greater Antilles. Despite being a small island, Puerto Rico is known for its wide range of microclimates, due to its topography and location. Rainfall is the most important parameter in the day to day forecast operations at the Weather Forecast Office in San Juan Puerto Rico. Precipitation patterns for 2010 were abnormal, with amounts up to 49 percent above normal (149%). Since January 2010, Puerto Rico experienced considerable increase in monthly rainfall amounts, where in some weather stations records have been broken. Even during the dry months (January, February and March), precipitation were well observed above normal. The focus of the research was on such rainfall episodes. Selected precipitation quantities from January to May 2010 were chosen to compare with years of similar behavior (wet patterns). The years preferred were 1956, 1975, 1985, 1989, 1996, 1998 and 2004. Case studies were chosen from 5 weather stations, Coloso, Paraíso, Ponce 4E, Rio Piedras and San Juan. The data used for this study was retrieved from the climatological local data of Puerto Rico provided by National Climatic Data Center (NCDC) and Xm Applied Climate Information System (XmACIS) database. The study investigates how the rainfall rates were above the normal mean. The data revealed that 2010 has been the wettest year for the last 30 years. January and May of 2010 were the months where the precipitation quantities were dominant. In fact, January was the month with significant accumulated rainfall for San Juan and Rio Piedras Station. The significant events studied from the past selected years showed no correlation with 2010 precipitation rates.