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Will there be a drought in Panama next year?
El Niño 2015-2016 and the Importance of Long-term Monitoring

October 26, 2015

Will there be a drought in Panama next year?<br/>El Niño 2015-2016 and the Importance of Long-term Monitoring

Panama, along with much of Central America, northern South America and the Caribbean, is experiencing the driest, and possibly, the hottest year on record

Panama, along with much of Central America, northern South America and the Caribbean, is experiencing the driest, and possibly, the hottest year on record. This year's El Niño is likely the most intense since the record-setting event of 1997-1998. How do we know this? Agencies such as the Panama Canal Authority (ACP), Panama’s national meteorological service, and the Smithsonian have been monitoring Panama’s climate for over a century.

Only based on high quality long-term monitoring data is it possible to know how past events affected Panama, and to say with authority that this year’s weather is truly extraordinary. By the same token, without long-term biological monitoring carried out by STRI, it would be impossible to evaluate how extreme climate conditions affect the animals and plants that must deal with them.

What has happened so far?
EARLY START

The current El Niño event began in March, whereas most events do not begin until around May. So the effects began to be felt in Panama in May, rather than the usual July. With the exception of only two weeks, rainfall measurements on Barro Colorado Island from the beginning of May to the middle of August were all below normal. The total rainfall recorded up to Aug 18, was 989.5mm, the lowest ever recorded since records began in 1925. Similarly, the ACP also reports record low rainfall for the entire Panama Canal watershed. Severe drought conditions have been reported in over 90 percent of the country.

What is happening right now?
RECENT RAINS NOT ENOUGH

Rainfall, especially around the Panama Canal, has increased considerably since mid-August. Rainfall around Panama City has even exceeded long-term averages. Water levels in Lakes Gatun and Alajuela have finally begun to recover. But this recharge usually begins much earlier in the rainy season and these artificial lakes, which provide the water needed to operate the Panama Canal and to supply potable water to Panama City, are still much lower than they would normally be at this time of year. If rains continue as they have, at best we can expect Gatun lake levels to reach the same levels as in 1997.

What is likely to happen?
EARLY DRY SEASON?

Forecasts for the next three months differ — Panama’s national meteorological program run by ETESA predicts near average rainfall in the area of the canal, but continued drought in much of the rest of the country, while the Water Center for the Humid Tropics of Latin America and the Caribbean (CATHALAC) is predicting normal or above normal rainfall for most of the country. Data from 1982 and 1997 indicate a pattern of increased rainfall is typical for this time of the year during major El Niño events. Unfortunately, these same data also indicate that the next dry season may begin a few weeks earlier than normal – possibly in late November..

We will almost certainly arrive at the end of 2015 with both Gatun and Alajuela well below normal levels. Once dry season begins, both lakes will begin to fall quickly leading to the very real possibility of severe water shortages in April and early May. Only exceptionally high rainfall during the next three months and a normal beginning date for the next dry season have the potential to alter this scenario.



What's next?
ENTER LA NIÑA

The good news is that there is a high probability that this El Niño event will be followed by its alter ego, La Niña. La Niña events are the reverse of El Niño, with cooler than normal waters in the equatorial Pacific and, often, rainier that average periods in Panama. The same long-term monitoring data that allows us to compare previous El Niño events also indicate that La Niña has immediately followed almost all major El Niño events. The greater than average rains predicted would help reestablish normal water levels in the Panama Canal. However, STRI long-term biological monitoring experiments have documented how a La Niña event following a major El Niño can negatively impact many groups of plants and animals – even leading to a generalized fruit failure and the subsequent famine for all the animals that depend on that fruit.

PULL QUOTES:

Severe drought has been reported for more than 90% of Panama

Central Panama's most important reservoirs — Gatun and Alajuela — will almost certainly enter an early-onset dry season at well below average levels



STATS:
BCI RAINFALL TO SEPT:

1976 − 1299.7mm

1982 − 1479.6mm

1997 − 1227.4mm

2015 − 1082.2mm

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