Once in a Generation Dry March for Antigua!*

30 03 2015

Dale C. S. Destin |

We are about to exit a severely dry March for most of Antigua. So far for the month, the Met Office, located at the V. C. Bird International Airport, has measured only 8.4 mm of rainfall. This severe dryness only happens once in a generation, on average. This total is not expected to change much between now tomorrow, when the month ends. Hence, this is likely to be among the top five driest Marches and the top 10 driest month of all times.

Top 4 Driest Marches for Coolidge, Antigua
March 2015 in perspective

Barring unexpected appreciable rainfall over the next 24 hours, this will be the fourth driest March on record dating back to 1928. Only March 1999, 1944 and 1930 have been drier.

Relative to other months, this March ranks 10th of all 1047 months of recorded rainfall, at the Airport, for the period.

The probability of March having such little rainfall is quite low; it’s around 3%. This means that this severe dryness we have experienced only happens once in every 33 Marches or once in a generation, on average.

Looking at the year on a whole, this is a 17 year event. The probability of a (any) month of a year, at the Airport, yielding 8.4 mm or less is around 6%. This means that this happens once every 17 years, on average.

March is the second driest month at the Airport with an average rainfall of 46 mm (1.81 in). The minimum and maximum rainfall totals on record are zero and 179.1 mm (7.05 in) respectively.

Drought

Currently, we are in our worse drought, in terms of intensity, since 2002/2003 and it is likely to get worse. We have been in a drought since September 2013.

It reached serious levels in 2014 but was reduced to slight levels in October 2014. At the end of January 2015 it had reintensified to moderate levels and with this month being brutally dry, it is set to drop to severe levels.

Projections

However, seasonal forecasters are not optimistic about rainfall for much of the rest of 2015. Indications are that El Nino, which tends to restrict our rainfall, mainly in the rainy season, is expected to continue deep into the year.

Additionally, the tropical North Atlantic sea surface temperatures are projected to remain near normal for much of the rest of the year. This is generally not helpful for rainfall in our nook of the world.

If El Nino strengthens to moderate levels or worse, our rainfall deficits are likely to be worse that those of last year’s. Recall that last year that we had a water crisis which are yet to get over.

Further, strategies and tools are required to sustainably deal with our water insecurity issues. Two such required tools are an integrated water resource management programme and an integrated drought management programme. Meanwhile, be conservative and efficient with your water usage.

[*It turned out that unexpected heavy downpours stopped March from having “once in a generation” dryness. The heavy downpours that stopped this March from being the fourth driest occurred after midnight on March 31. However, In meteorology, the last day of a month ends at 8 am on the first day of the next month. .

So, instead, the eventual total rainfall for March, at the Airport, was 11.9 mm, the driest since 2001, the seventh driest March and the 18th driest month on record. This kind of dryness, instead, happens once in every 16 years, on average]








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