The Driest Year for Antigua since at Least 1871

21 12 2015

Dale C. S. Destin |

Earlier this year, we indicated that Antigua could see its driest year on record. Regrettably, this is coming to past. The country is on its way to having the driest year on record dating back to at least 1871 or 145 years ago.

Up to the end of November, the rainfall total stood at 525.8 mm (20.70 in). Based on measured rainfall, it’s the lowest on record for any January-November period dating back to 1928. Further, based on statistical analyses, we are almost 100% certain that this is the driest such 11 months since 1871.

Annual Rainfall for Antigua. Blue line - rainfall; heavy grey line - normal rainfall using base period 1981-2010

Annual Rainfall for Antigua. Blue line – rainfall; heavy grey line – normal rainfall using the base period 1981-2010.

It would take perhaps a miraculous deluge to prevent the 1983 record (681.5 mm or 26.83 in) from being broken. Over six inches of rain is required in December to prevent the record from being broken. Thus far for the month, the rainfall total is less than an inch.

There have been only 11 times in 88 years when the rainfall for December has exceeded 155.7 mm (6.13 in) – the amount required to prevent the record from falling. The probability of this happening is around 12%, El Nino or not. Currently, we are at least 70% certain that this rainfall will not materialize.

We could also see our record driest wet season (July-December). Statistically, there is a very low chance of this happening – around 8%; however, given the near record low rainfall for the month thus far, the chance is increasing.

We do not actually have data from our current stations going back beyond 1928. However, with the use of regression analysis, we were able to use other datasets to successfully extend our record back to 1871. So we now have very high quality datasets of annual and some seasonal rainfall totals dating back 145 years.

Like Antigua, most of the eastern half of the Caribbean could also see record-breaking low rainfall for 2015.

Caribbean Rainfall - Dec 2014 to Nov 2015

Nov 2014-Dec 2015 SPI. The darker the reds, the drier the weather; the darker the blues, the wetter the weather. Record or near record low rainfall for much of the eastern half of the Caribbean basin.

El Nino, Saharan dust and a positive North Atlantic Oscillation are the main culprits for the parched weather conditions for this year.

Keep following this “space” for more insights into the rainfall for Antigua and the Caribbean. Unfortunately, we have additional undesirable statistics to share with you on this subject.

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Record Breaking Rainfall

11 05 2012

by Dale C. S. Destin

This is the wettest start to May at the V. C. Bird International Airport, based on available record, which dates back to 1971. The rainfall for the first seven days of May, 2012 is now the most on record for all Mays with 121.9 mm or 4.80 inches; the previous highest was 63.4 mm or 2.50 inches recorded in 1990. The rainfall was caused by a persistent deep-layered trough system, which channelled a lot of moisture from South America into the area resulting in periods of rain, showers and thunderstorms. The heaviest rainfall occurred on Saturday, 5 May with 76.5 mm or 3.01 inches falling in a short period of time, about 3 hours. This resulted in minor to moderate flooding in some low-lying and flood prone areas. May 5 also had its highest total on record, and it tied with May 30, 1992 for the fourth wettest day for all Mays.

Our outlook for May calls for above normal rainfall and near normal temperature and wind. Given what has happened thus far, we could easily see this May becoming one of the top 10 wettest Mays on record. Does anyone want to guess/forecast what the final rainfall total for the month at the airport is going to be?  Here is a guide; the average and median totals for May 12 – 31 are 16.6 and 25.1 mm respectively; the max and min totals are 444.8 and 7.5 mm respectively (1981 – 2010). What is your guess/forecast total for the month? Tweet us at www.twitter.com/anumetservice or www.facebook.com/anumetservice.

Daily Rainfall Totals at the V. C. Bird International Airport – May 1 to May 7, 2012:

May 1    1.0 mm or 0.04 in

May 2    3.0 mm or 0.12 in

May 3    10.7 mm or 0.42 in

May 4    0.9 mm or 0.04 in

May 5    77.9 mm or 3.07 in

May 6    10.6 mm or 0.42 in

May 7    17.8 mm or 0.70 in





Record Breaking Rainfall over the Past Two Years

29 03 2012

As we continue to see a drying trend across our area, the record shows that the past two years ending February 2012 was the wettest on record. The total for the period March 2010 to February 2012 was 129.80 inches; the previous highest was 129.72 inches recorded over the period March 1951 to February 1953; this was 59 years ago. The normal rainfall for this period is 93.88 inches. Recall that prior to the past very wet period, we had a serious drought during the second half of 2009 through early 2010. We may be heading into another Meteorological Drought over the next few months.








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