THE CARIBSAVE CLIMATE CHANGE RISK ATLAS

MAM and JJA (early wet season) rainfall. Changes to rainfall in the wettest season (SON) are less consistent
between models.
RCM projections of rainfall for Jamaica are strongly influenced by which driving GCM provides boundary
conditions. Driven by ECHAM4, RCM projections indicate moderate decreases in MAM and JJA rainfall, but
very little change in total annual rainfall. Driven by HadCM3, the projections indicate dramatic decreases in
rainfall, particularly in JJA and SON. These HadCM3-driven projections correspond with those that are at
the most extreme end of the range of GCM projections.
Observed
Mean
1970-99
(mm per
month)
Table 3.3.1: Observed and GCM projected changes in precipitation for Jamaica
Observed
Trend
1960-2006
(change in
mm per
decade)
Jamaica: Country Scale Changes in Precipitation
Projected changes by
the 2020s
Change in mm per
month
Min Median Max
10
Projected changes
by the 2050s
Change in mm per
month
Min Median Max
Projected changes by
the 2080s
Change in mm per
month
Min Median Max
A2 -10 -2 0 -27 -4 7 -40 -8 1
Annual 155.2 -2.4 A1B -20 0 11 -29 -3 4 -27 -8 11
B1 -13 -3 11 -16 -3 7 -23 -6 8
A2 -9 -4 5 -13 0 20 -18 -1 17
DJF 107.2 0.2 A1B -7 -2 19 -16 0 8 -14 -3 21
B1 -11 -1 11 -8 -2 6 -15 0 4
A2 -7 -2 12 -13 -5 8 -26 -7 0
MAM 142.4 1.8 A1B -13 0 14 -17 -1 4 -12 -6 5
B1 -12 -2 7 -13 0 17 -13 -3 15
A2 -21 -6 3 -46 -15 23 -64 -32 -5
JJA 141 -6.2 A1B -34 -7 36 -47 -13 5 -54 -24 0
B1 -24 -10 3 -20 -5 7 -34 -14 6
A2 -19 0 8 -38 -1 21 -53 -2 26
SON 227.6 -4.5 A1B -32 1 32 -43 0 18 -49 -2 49
B1 -28 -5 43 -31 -4 19 -37 -9 25