Rainy fall made ’09 almost average

Significant rain between September and December not only saved 2009 from being the driest on record in the Cayman Islands, it made the year almost normal in terms of total rainfall.

In the end, 49.99 inches of rain fell in 2009, about 13 per cent less than the 56.48 inches of rain that falls during a normal year.

National Weather Service Meteorologist Allan Ebanks said the above-normal rainfall in the fall compensated for the below-normal rainfall that fell in the summer months in 2009.

July and August were the driest on record in the Cayman Islands. Only 2.32 inches of precipitation fell during those two rainy-season months combined, well below the 12.16 inches that normally falls during that time period.

The pattern started changing in September, when 9.54 inches of rain fell, one and a half inches more than usually falls in the month.

October, however, was by far the wettest month of the year, bringing 16.16 inches or rain, almost twice the 8.55 inches that normally falls. During October, 6.52 inches of rain fell in one 24-hour period alone.

October is historically the rainiest month of the year in Cayman, which is the main reason the National Festival Pirates Week was moved from late October until the second week of November three years ago.

Mr. Ebanks said he remembered when the Pirates Week Committee approached the National Weather Service for statistics about rainfall in October.

‘They were thinking about moving it up to early October, but we told them that sometimes it’s just as rainy in early October as it is later in the month. We told them the second week of November was probably the best time.’

November and December 2009 were also slightly rainier than normal, with 7.26 inches and 3.09 inches falling during those two months respectively, compared to the normal 6.63 inches and 2.95 inches of rainfall during those months.

In the end, 36.05 inches of rain fell in the last four months of the year. That amount alone was enough to surpass the figure for the lowest amount of rain in an entire calendar year, which was 35.61 inches in 1997. The weather that year was affected by a particularly strong El Niño event.

The El Niño phenomenon, which is caused by above-normal sea surface temperatures in the tropical Pacific Ocean, is known to reduce rainfall in Caribbean region. Last year also featured a strong El Niño, although it wasn’t as intense as the one in 1997.

Last year’s El Niño is still occurring and is forecast to persist at least through June, although it is expected to begin weakening early this year.