Rainfall in the ABC Islands during July 2009 was well below normal (57%) in many locations in especially Curaçao and Bonaire. Hato Airport in Curaçao reported 23.0 mm against a long-term average of 40.2 mm for July.
Aruba however was an exception and had a rainfall amount well above normal (70%). Queen Beatrix Airport observed 52.8 mm against a monthly average of 30.7 mm. In the SSS Islands, less rain than normal (58%) was measured as well. At the Princess Juliana Airport in St. Maarten, an amount of 41.6 mm was measured while the monthly average for July is 71.6 mm.
Through the end of July, no tropical storms or hurricanes developed over the Atlantic Basin. The first (short lived) tropical depression of the year did manage to develop at the end of May but since then things have been very quiet. On average, 1.6 named storms (tropical storms and hurricanes) develop during the months of June and July over the Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Last year (2008), during this same period, four tropical cyclones had developed already over this region. Two of these reached hurricane intensity and one of these (Bertha) became a major category three hurricane.
The sea surface temperature in the Caribbean Area and the tropical Atlantic Ocean has increased somewhat during the past few weeks to normal values for the time of the year. This development is favorable for the formation of rain clouds and the development of tropical cyclones in these regions.
Observations in the tropical Pacific Ocean indicate that the sea surface temperature continues to rise there. This means however that the famous El Niño phenomenon has returned and the forecast is that it will continue to gain intensity during the next few months. As a result of this development, the amount of rain in the southern Caribbean Area (including the ABC Islands) and northern South America will be less than normal. The amount of tropical cyclones over the
Atlantic Basin will also be suppressed this year (ten tropical storms, four hurricanes and two major hurricanes). About average rainfall amounts are forecast for the SSS Islands during this same period.