SIX-MONTHLY OUTLOOK FOR ANTIGUA
JUN TO NOV 2017

 Dale C. S. Destin (follow @anumetservice)

 

Antigua and Barbuda Meteorological Service
Climate Section

   

Issued Jun 17, 2017

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Based upon model data, observations and subjective input, the following is the rainfall and temperature outlook for Antigua for the period June to November 2017:  

Rainfall

Above normal rainfall is likely, with a confidence of 55%. The chace of drier than normal conditions is slight - 15%  The island-average rainfall is likely to be greater than 838.2 mm (33.0 in). Probabilistically, there is a

   •  55% chance of above normal rainfall;
   •  30% chance of near normal rainfall (637.5 to 838.2 mm or 25.1 to 33.0 in) and
   •  15% chance of below normal rainfall.

Temperature

Warmer than normal temperature is likely, with a confidence of 55%. The chance of cooler than normal weather is slight - 15%. The mean temperature is likely to exceed 27.9 °C (82.2 °F). Probabilistically, there is a

  •  55% chance of above normal temperature;
  •  30% chance of near normal temperature (27.7 to 27.9 °C or 81.9 to 82.2 °F) and
  •  15% chance of below normal temperature.

This outlook is largely predicated on sea surface temperature (SST) patterns across the tropical Atlantic and Pacific Oceans.

More outlooks: Jun, Jun to Aug, Sep to Nov, Drought  

The next will be issued by July 7.  

 
 

Definition

The following definitions are being observed based on the 1981 to 2010 dataset:

  •  Well below normal: Values in the lowest 10% of the dataset
  •  Below normal (lower/less than normal): Values in the lowest 33.3% of the dataset
  •  Near normal (normal or usual): Values in the middle 33.3% of the dataset
  •  Above normal (more/higher than normal): Values in the highest 33.3% of the dataset
  •  Well above normal: Values in the highest 10% of the dataset


Background

CliSec's six month outlooks are general statements about the probability or risk of above, near or below normal (rainfall) over a six-month period. The outlooks are based on the statistics of chance (the odds) taken from Antigua's rainfall and mainly sea surface temperature records for the tropical Pacific and Atlantic Oceans. They are not, however, categorical predictions about future rainfall, and they are not about rainfall within individual months of the six-month outlook period.

Probability outlooks should not be used as if they were categorical forecasts. These outlooks should be used as a tool in risk management and decision making. The benefits accrue from long-term use, say over 10 years. At any given time, the probabilities may seem inaccurate, but taken over several years, the advantages of taking account of the risks should outweigh the disadvantages. For more information on the use of probabilities, farmers could contact their local departments of agriculture.


Disclaimer

The information contained herein is provided with the understanding that the Antigua and Barbuda Meteorological Service makes no warranties, either expressed or implied, concerning the accuracy, completeness, reliability, or suitability of this outlook. The information may be used freely by the public with appropriate acknowledgement of its source, but shall not be modified in content and then presented as original material.