1. Building the Weather to
Climate Bridge Across Jamaica:
implications for future re-engineering.
Teddy Allen
Post-Doctoral Scientist – The International Research Institute for Climate and Society
tallen@iri.columbia.edu

2. CLIMATE WEATHER CLIMATE
CHANGE
CLIMATE ?
7 + 8 + 8 + 7 + 12 + 7 + 9 + 8 + 7 + 15 + 7 + 7 + 8 + 13 + 7
7 + 8 + 8 + 7 + 12 + 7 + 9 + 8 + 7 + 15 + 7 + 7 + 8 + 13 + 7 = 8.5
klima (Ancient Greek) = slope, terrestial latitude

3. CLIMATE WEATHER CLIMATE
CHANGE
Jamaican climate (rainfall)
Climate knowledge is important:
Supports cropping calendars
Helps to determine specific crops to plant
Hurricane awareness

4. CLIMATE WEATHER CLIMATE
CHANGE
WEATHER ?
The current state of
the atmosphere

5. CLIMATE WEATHER CLIMATE
CHANGE
Jamaican weather (rainfall)
What causes rainfall in Jamaica during the early rain season?
IMPORTANCE OF EARLY RAIN SEASON:
cessation of dry season
first stage of seasonal agriculture
provides economic prosperity
conditions seasonal water levels
offsets possible drought
What causes it? Can we predict it?

6. CLIMATE WEATHER CLIMATE
CHANGE
Rethinking Jamaican rainfall
early rain season
July
Upper level westerly winds
April early rain season
Atmospheric water vapor
Panama Low
during the early
rain season

7. CLIMATE WEATHER CLIMATE
CHANGE
May 20, 2011
2011
hr – May 20,2011
accumulation of
weather events
DAILY
MONTHLY

8. CLIMATE WEATHER CLIMATE
CHANGE
2012 satellite based rainfall
(early rain season)
2012 satellite based
accumultaed rainfall
(early rain season)

9. CLIMATE WEATHER CLIMATE
CHANGE
2000 2001 2002 2003 2004
2005 2006 2007 2008 2009
2010 2011 2012 2013 2014

10. CLIMATE WEATHER CLIMATE
CHANGE
Jamaican weather to climate bridge:
the Caribbean rain-belt
Caribbean Rain Belt (Car-belt)
( an average of all of the ERS rainfall
accumulations from 1999-2014 )
Daily rainfall  seasonal totals  average of seasonal totals  climatological rain-belt

11. CLIMATE WEATHER CLIMATE
CHANGE
Climate Change and the Caribbean Rain-Belt
end of century projections
Sea Surface TemperatureSurface Air Temperature Rainfall
warmer air  warmer sea surface  more available moisture  DRIER???
We can expect a change in circulation that weakens the uplift environment.

12. CLIMATE WEATHER CLIMATE
CHANGE
Seasonal Changes in Projected Rainfall
Jan-Mar Apr-Jun
Jul-Sep Oct-Dec

13. CLIMATE WEATHER CLIMATE
CHANGE
How will the climatological bi-modal rainfall pattern and
the Caribbean rain-belt change in time?
WHATWEEXPECTPOSSIBLFUTURE
Farmers and water resource managers may need to adapt to fewer
“weather events” during the wet season.

14. CLIMATE WEATHER CLIMATE
CHANGE
CONCLUSIONS
• Current late spring rainfall climate results from expected weather events
caused by a combination of upper level uplift dynamics and lower level
moisture steered by the Panama Low
• The long term average of these weather events produces the Caribbean Rain-
Belt
• End of century projected rainfall suggests about 20% reduction in annual
rainfall totals with much greater reduction during the summer months
• A shift in expectation of weather events must occur to prepare for possible
climate change scenarios
Fruitful collaboration and discussions with: UWI, Jamaican Meteorological Service,
Brian Mapes, IRI, CIMH, CaribSave