Dale C. S. Destin – 02 May 2023 | The year will most likely be drier than usual for Antigua. My early forecast calls for the rainfall total for 2023 for the Country to be around 1081 mm (42.6 in) with a 70 percent or high confidence of it being in the range of 847 to 1355 mm (33.3 to 53.3 in).

The highest probability – 39 percent, is for below normal rainfall; hence, the predictions for a most likely drier than normal year. The numbers can also be interpreted as a 74 percent chance of below or near-normal rainfall for 2023.

It is also very unlikely that the year will be wetter than normal, with only a 26 percent chance; there has only been one such year in over a decade – 2020.

It is unclear as to what are all the causes for the below-normal rainfall forecast; however, El Niño is likely to develop during the next three months and continue through 2023. 

El Niños usually cause reduced rainfall, especially during the wet season for our area by causing subsidence and vertical wind shear making it hard for rain clouds to form. Subsidence is the opposite of the convection required for most of our rainfall; vertical wind shear makes it difficult for clouds to grow to maturity.

There are uncertainties in the forecast mainly due to uncertainties regarding the formation and strength of  El Niño and the counteracting effect of an expected warmer-than-normal tropical  North Atlantic (TNA).

Read more: https://268weather.wordpress.com/2023/05/02/early-prediction-below-normal-rainfall-most-likely-for-antigua-for-2023/