March to August 2018 Climate Outlook for Antigua and Barbuda

30 03 2018

Dale C. S. Destin |

Antigua and Barbuda remains in, at least, a meteorological drought. The latest round of climate outlooks suggest that it is most likely to worsen, over the coming three to six months. Signs of the dry weather is becoming quite evident, with Potworks Dam transitioning from a water catchment to a temporary sesonal desert. Drought is occurring and drought watch and warning are in effect for the medium to long-term.

Potworks Dam, Antigua; Mar 13, 2018; Almost Totally Dry. Image courtesy Karen Corbin of the Humane Society

Potworks Dam, Antigua, Mar 13, 2018; Almost Totally Dry. Image courtesy Karen Corbin of the Humane Society. At its max, it holds a billion gallons of water.

Rainfall and drought

Last month, we indicated that the drought was unlikely to worsen or could come to an end in the next three months. This months, the climate indicators are indicating that the drought will mostly worsen and continue for the next six months, at least.

ProjectedRainfall_Dec 2017-May2018

Based on the latest round of forecasts, we will likely be facing more than a meteorological drought. Other droughts that could be on the way, if not already with us, are agrometeorological, Hydrological, socioeconomic and ecological droughts.

For the medium term: at the end of the nine-month period ending June 2018, a drought watch is in effect, as a moderate drought or worse is possible for Antigua. Meanwhile, for the long-term: 12-month period ending August 2018, a drought warning is in effect, as a moderate drought or worse will most likely be occurring. It is possible this period could experience serious drought.

Temperature

Temperatures, including maximum and minimum, were generally near normal or the usual for the December-February (DJF) period, based on the climate period 2001-2015.

Looking down the road over the period March to May– above to near normal mean maximum temperature is likely. Otherwise, equal chances of  below, near or above normal mean temperature and mean minimum temperature. In other words, the current climate signals do point in any given direction as to what is likely to happen with these temperatures.

For the period June to August, the mean and maximum temperature are expected to be above to near normal or warmer than usual to usual. Meanwhile, temperature is equal chance of below, near or above normal mean minimum temperature.

El Nino Southern Oscillation

The cold phase of El Nino Southern Oscillation (ENSO) – La Nina is evident; however, it will be short-live, as already, it has started to transition back to ENSO-neutral conditions. The transition to the neutral phase is expected to conclude by the end of May, with a 55 percent confidence.

In our part of the world – the Caribbean, a moderate or strong La Nina is almost always welcome, particularly in the summer when it has a usual positive impact on rainfall. The opposite – El Nino, has a negative impact. Fortunately or unfortunately, outside the wet season – July to December, ENSO has little or no effect on our rainfall.

La Nina is also welcome from a temperature standpoint, as it usually bring welcome cooler than normal weather. The reverse is true.

Tropical North Atlantic

Over the past three months, the tropical North Atlantic sea surface temperatures (TNA-SSTs) has gone from warmer than usual to colder than usual. However, overall, for the period November-January, TNA-SSTs were warmer than usual. For the upcoming March-May period, TNA-SSTs will likely be at the usual or cooler than usual for this time of the year. Historically, these temperatures seems not associated with any particular rainfall total for March to May.

Regarding temperature, higher that normal TNA-SSTs are associated with higher than usual temperatures for Antigua and vise-versa.

Both ENSO and TNA-SSTs are pointing toward near to below normal temperatures for Antigua. This is interesting, drought conditions are expected to continue and drought normally comes with warmer than normal weather. Current trend seems consistent with ENSO and TNA-SSTs signals.

See the following links for the full outlooks: CariCOF Newsletter – summary and outlooks for the regionprecipitation outlooks and temperature outlooks.

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“Tropical Storm Gonzalo” On Our Doorsteps

12 10 2014

Dale C. S. Destin

Gonzalo_Satellite1

We are following an area of disturbed weather that could become the seventh named storm of the hurricane season – TS Gonzalo. It is about 280 miles east of Antigua and has the potential to cause storm-force winds across the island and the rest of the northeast Caribbean. Click link for more








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