Influences of El Nino and Climate Change on weather in Central America

Supplement to lecture by Prof. Daniel Cohan (Rice University) for alumni cruise to Costa Rica and Panama


  1. Talk given February 2, 2016
  2. Storify last updated: February 2, 2016
  3. First, let's look at the typical weather of Central America.
  4. As we know, it's warm
  5. Or, hot, on a different scale
  6. Central America overall gets a lot of precipitation, with a tropical location that accelerates evaporation. The exception is areas in the rain shadows of mountain ranges.
  7. Moving from annual conditions to seasonal ones, we see that the weather is delineated by two seasons: dry (called verano or summer) and wet
  8. Note the inverse correlation between sunshine and rain -- a helpful blend for a country that gets 99% of its power from renewable energy, mostly hydropower with growing solar share.
  9. Another illustration of rainfall patterns, in Tocumen, Panama, shows the intense difference between the dry and wet seasons.
  10. Large amounts of rain can come in individual tropical cyclone events, from either the Pacific or the Atlantic
  11. Note also in the sunshine image that Costa Rica gets much more hours of sunshine in January than in June. That's despite the fact that the Sun is more directly overhead in June (as true throughout Northern Hemisphere).
  12. We can illustrate this fact, and link with our energy discussion, by looking at how much electricity would be generated by solar panels in this region. I use National Renewable Energy Laboratory's PVWatts Calculator to do so.
  13. PVWatts chooses Rivas, Nicaragua as the nearest weather station to Panama or Costa Rica -- oh well, close enough for now (Hope NREL works to make it more international).
  14. The calculations show solar radiation reaching the ground (or solar panels) peaks in February at 6.45 kWh/m2/day vs minimum of 4.05 kWh/m2/day in June. In other words, the Northern Hemisphere solstice is in the month with the least sunshine reaching the ground in Central America!!