By Dale C. S. Destin – Published 24 April 2024 |
The year will likely be wetter than usual for Antigua. My early forecast calls for the rainfall total for 2024 for the Island to be above normal and possibly be among the wettest on record.
Forecast Details
This year will most likely get around 1417 mm (55.0 in) with a 70 percent confidence of it being in the range of 1108 to 1778 mm (44.0 to 70.0 in). It is also possible that the year will be seriously wet or have well-above-normal rainfall, with more than 1534.4 mm (60.41 in).
The highest probability – 70 percent, is for above-normal rainfall; hence, the prediction for a likely wetter than normal year. The numbers can also be interpreted as a 91 percent chance of above or near-normal rainfall for 2024. On the other hand, it is also extremely unlikely that the year will be drier than normal, with only a 9 percent chance of such.
The year could also see super wet weather or well-above-normal rainfall. There is a 39 percent chance of the year’s rainfall falling in the top 10 percentile of all rainfall for the data period of 1991-2020.
This would be the wettest year since 2011, if the forecast pans out. It would be the 19th wettest year in the 97-year record, which dates back to 1928.
Impacts
Given the forecast, excessive rainfall could lead to flash flooding of mainly flood-prone areas. Potential impacts from flooding include the following:
- Loss of life and injuries
- Damage to infrastructure
- Temporary displacement of families
- Disease outbreak
- Crop and animal losses
- Contamination of potable water
- Widespread financial losses
- Disruption of transportation
- Soil erosion
- Environmental degradation
- Disruption of schools
- Damage to dams, embankments, irrigation and drainage facilities
- Decrease in storage capacity of reservoirs due to high sediment rate
- Disruption of communication
- Temporary stoppage of health services
The Reason for the Wet Forecast
Like the hurricane season, the primary factors driving 268Weater’s above-normal rainfall forecast are the expectation of persistently warmer-than-normal sea surface temperatures (SSTs) across the tropical North Atlantic (TNA), coupled with anticipated cooler-than-normal SSTs across the eastern Equatorial Pacific Ocean or La Niña.
The simultaneous occurrence of these phenomena, during the latter half of the year or the wet season, sets the stage for what could be near-perfect conditions for a super wet year. However, there are uncertainties regarding the forecast; these are mainly due to the unknowable intensity and frequency of Saharan Dust that will traverse the TNA. Dust inhibits rainfall activity, but it cannot be forecast beyond days; hence, it is not factored into the year’s rainfall forecast.
Usual Rainfall
A typical year, based on the new standard climate period 1991-2020, averages 1156.7 mm (45.54 in). The forecast total of 1417 mm is 123 percent of the yearly average; a surplus of 260.3 mm (10.25 in). Usually, fall/autumn – September-November, accounts for 58 percent of the wet season total and 38 percent of the year’s total.
Dry Season Forecast After initially being forecast to be drier than usual, the dry season (January-June) has been quite wet. Thus far, it is the wettest January-March since 2006 and the fifth wettest such period on record dating back to 1928, with 287.8 mm (11.33 in) of rainfall. There is now a 68 percent chance of the dry season ending up wetter than normal and possibly (34% chance) super wet, with rainfall totaling over 648 mm (25.5 in).
The forecast is for the dry season to have 530 mm (20.87 in) with high (70 percent) confidence of it ranging between 372 to 726 mm (14.65 to 28.58 in). The dry season averages 410 mm (16.14 in); hence, this one could be more than 29 percent wetter than usual.
Last Year
Rainfall-wise, last year–2023, will be most remembered for the near record-breaking rainfall of October from Hurricane Philippe. The average total for the month was 364.2 mm (14.34 in). Philippe was the biggest rainmaker, dowsing the country with over 200 mm or up to 8 inches of rain. This resulted in significant flash floods.
Rest of the Caribbean
Rainfall totals are also running above normal across the rest of the northeast Caribbean, so far for the year. Above-normal rainfall is likely to continue across these islands and spread to much of the rest of the Caribbean. A wetter-than-normal year is likely for the region due to the same conditions that are likely to cause wetter-than-normal weather for Antigua.
Conclusion
Given the wetter-than-normal forecast, it’s crucial to prepare for higher chances of excessive rainfall and flash flooding this year. Stay informed, update emergency plans, and take necessary precautions to protect lives, livelihoods and property. Let’s act now to enhance resilience and minimize potential consequences.
Regardless of the forecast, we all need to conserve water and be as efficient with its use as much as possible. Reducing our water footprint will redound to our individual and collective socio-economic benefit.
This forecast will be updated monthly around the 22nd of each month until August. The first update will be issued around May 22.
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Dale Destin - 268Weather 
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