SPI Monitor April 2010

Disclaimer

The information contained herein is provided with the understanding that The Caribbean Institute for Meteorology and Hydrology makes no warranties, either expressed or implied, concerning the accuracy, completeness, reliability, or suitability of the Outlook. The information may be used freely by the public with appropriate acknowledgement of its source, but shall not be modified in content and then presented as original material.

Discussion

April 2010

The middle two weeks of April 2010 provided the region, in particular, the eastern Caribbean, with high rainfall and welcomed relief from the drought conditions. The eastern Caribbean, including Guyana, experienced conditions ranging from, near normal (in the negative in Tobago) to extremely wet in Dominica. The Dominican Republic was also near normal. Conditions in Jamaica ranged from near normal in the west to moderately wet in the east. In Belize, conditions were near normal in the north to moderately wet in the southwest.

February  to April 2010

For the 3 month period, the southern portion of the eastern chain (particularly Grenada and Tobago) showed drier conditions than the northern portion. This was predominantly due to the high rainfall experienced in the middle two weeks of April. North of the Grenadines, the chain was near normal to extremely wet for the period. Guyana was near normal for the period. The western portion of the Dominican Republic was below normal whilst the eastern portion was normal. The western portion of Jamaica was normal whilst the eastern portion was moderately wet. Further to the west, Cayman Islands and Belize were normal.

November 2009 to April 2010

For the six month period, the southern portion of the eastern chain, from Trinidad northward to St. Vincent and Barbados, was severe to extremely dry. The remainder of the eastern chain was near normal. Guyana was normal in the west and moderately dry in the east. Apart from an area in the northeast that was moderately dry, the Dominican Republic was generally near normal for the period. Jamaica, Cayman Islands and Belize were all near normal for the period.

May 2009 to April 2010

From the period May 2009 to April 2010, Trinidad and Grenada experienced severe to extremely dry conditions. Barbados and St. Lucia were moderately dry. The remainder of the eastern portion of the chain was normal. Guyana was normal to the north to extremely dry in the south. Apart from the eastern portion of the country that was moderately dry, Dominican Republic was normal. Jamaica, Cayman Islands and Belize were all normal for the period.

The maps produced used SPI values calculated from monthly rainfall totals from land stations and NCEP/NCAR reanalysis data. Only land station data is used for the eastern Caribbean , described here as from Georgetown Guyana in the south to Anguilla in the north. The Greater (and Western) Antilles is less represented by land stations. However efforts are being made to include more land stations from that part of the region. Note that the severity implied by the index is relative to what is normal for that period of consideration. Normal in the drier season reflects less rainfall than in the wetter season.