SIX-MONTHLY OUTLOOK FOR ANTIGUA – APR TO SEP 2016

 Dale C. S. Destin (follow @anumetservice)

 

Antigua and Barbuda Meteorological Service
Climate Section

   

Issued March 31, 2016

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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 April to September 2016:  

Rainfall

Below normal rainfall is expected, with a confidence of 80%. The chance of wetter than usual weather is very slight - 5%. The island-average rainfall is expected to be less than 513.1 mm (20.2 in). Probabilistically, there is a

   •  5% chance of above normal rainfall;
   •  15% chance of near normal rainfall (513.1 to 624.8 mm or 20.2 to 24.6 in) and
   •  80% chance of below normal rainfall.

Temperature

A warmer than normal mean temperature is expected, with a confidence of 80%. The chance of cooler than normal weather is very slight - 5%. Most likely the mean temperature will exceed 26.9 C (79.8 F). Probabilistically, there is a

  •  65% chance of above normal temperature;
  •  25% chance of near normal temperature (27.5 to 27.7 °C or 81.5 to 81.9 °F) and
  •  10% chance of below normal temperature.

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

The next will be issued by May 3.  

 
 

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 or 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 or 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.