Early Prediction: Below Normal Rainfall Most Likely for Antigua

21 04 2022

Dale C. S. Destin |

The year will most likely be another drier than usual one for Antigua. My early forecast calls for the rainfall total for 2022 to most likely be 1105 mm (43.50 in) with a 70 percent or high confidence of it being in the range of 811 to 1463 mm (31.93 to 57.60 in).

The main reason for the most likely below normal rainfall forecast is the current cooler than normal sea surface temperatures (SSTs) across the tropical North Atlantic (TNA), which should last, at least, into the second half of the year. Cooler than normal TNA SSTs favour suppressed rainfall conditions while the opposite enhances rainfall.  

The year started out with a severe drought brought forward. This drought started in the winter of 2020/2021 and continues through the present. January 2022 was wetter than January 2021, but it was still only 72 percent of the normal total. The last two months, February and March, have been wetter than normal resulting in the intensity of the meteorological drought easing to slight. This easing is likely to be a brief respite, given the forecast.  

The dry season, January to June, will likely be below normal with a 60 percent chance. The forecast is for 298 mm (11.73 in) with high confidence of it ranging between 182 to 459 mm (7.17 to 18.07 in). This dry season could also be one of the top 10 driest. There is a 33 percent chance of this happening with the possibility of the total falling below 254 mm (10 in). Currently, the total stands at less than 203 mm (8 in) with April running well below normal at less than 25.4 mm (1.0 in) and the forecast indicating a better than 70 percent chance of May-June being drier than normal.

WMO Lead Centre for Long-Range Forecast Multi-Model Ensemble is forecasting 70-80% likelihood of below normal rainfall for Antigua and Barbuda for May to July. Also, below normal rainfall is likely for much of the rest of the Eastern Caribbean.

A typical year, based on the new standard climate period 1991-2020, averages 1156.7 mm (45.54 in). The dry season averages 410 mm (16.14 in) and the wet season, July to December, averages 746.8 mm (29.40 in). The fall/autumn, September-November, accounts for 58 percent of the wet season total and 38 percent of the year’s total.

Rainfall-wise, last year–2021, will be most remembered for being the second driest on record with some parts of the country having record-breaking dry weather. There were likely significant socio-economic impacts but unfortunately, this has not been quantified.

This forecast will be updated monthly around the 21st of each month until August. The first update will be issued around May 21.

Regardless of the forecast, we all need to conserve water and be as efficient with its use as much as possible. Reducing our personal water footprint will literally redound to our individual and collective socio-economic benefit. Minimising your water footprint is also good for the climate and good for our environment.

Please share this blog, if you found it useful, and follow me for more on the evolving drought and for all things weather and climate – TwitterFacebook and Instagram.


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