Monitoring Agricultural Drought in the West Indies - Monitoring and Predicting Agricultural Drought: A Global Study - page 146

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Fig ure 11.2 Rainfall climatology of the Caribbean in millimeters/month, showing the early
(April-July) and late (August-November) rainfall season.

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1972, 1976, 1982-83, 1991, and 1997. The worst drought conditions
occurred in 1976 and 1991, when the island received 72% and 73%, respec-
tively, of normal total annual rainfall with respect to a 30-year mean. Simi-
lar responses to El Niño events have also been noted elsewhere in the West
Indies (e.g., rainfall totals of 150 mm less than average in Trinidad between
August and October during the 1997-98 event; Pulwarty et al., 2001).
Because the sea-surface temperatures in the Atlantic and Caribbean lag
those in the eastern equatorial Pacific by 4-6 months, La Niña events (cold
equatorial Pacific waters), which peak in boreal winter, can also induce
drought conditions in the early rainfall season of the following year. If
the La Niña phenomenon persists beyond the winter months, then sea-
surface temperatures in both the eastern equatorial Pacific and Caribbean
Sea are simultaneously below normal during the early portion of the West
Indian rainfall season. Chen and Taylor (2002) show that such conditions
at that time of year are often coincident with droughts in the region. Island-
wide meteorological droughts in Jamaica in 1971, 1974, 1975, 1985, 1989,
and 2000 (J. Spooner, National Meteorological Office, Kingston, Jamaica,
personal communication, 2002) are attributable to this scenario.
Some islands in the West Indies are large enough to generate their own
weather due to orographic effects, and hence some territories are more
prone to droughts than others. As an example, during the El Niño year
of 1997, the regions of Jamaica that experienced drought conditions dur-
ing the late rainfall season (August-October) were situated mostly on the
southern and eastern half of the island in the parishes of St. Thomas,
Kingston and St. Andrew, and St. Catherine (figure 11.3). Similarly, during
the La Niña year of 2000, it was primarily St. Thomas and St. Catherine
that were most severely affected in the early rainfall season (April-July),
though the drought also extended to the west, on the southern plains of
Clarendon and St. Elizabeth, and to the parish of Trelawny in the north of
the island.

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