A dry day is defined as a day with less than 1 mm of rainfall, and a dry spell as a period of consecutive dry days. It is important to consider dry spells in crop management, as significant spells can reduce yields or result in total failure, particularly where irrigation is not available. Depending on the soil properties related to soil moisture retention and drainage, and depth, typically 7 or more consecutive days (i.e. a dry spell of at least 7 days) can impact crop production.
To provide some insight into what is likely, the CariCOF Dry Spell outlook gives the probability, via maps, of having at least three 7-day and at least one 15-day dry spell, as well as the maximum number of 7-day and 15-day dry spells. It also provides a tabulated comparison of the average number of 7-day, 10-day and 15-day dry spells.
These outlooks are produced by CariCOF for the upcoming three-month period and updated monthly. For a better picture of the rainfall characteristics for the upcoming period, the dry spell outlook should be used in conjunction with other CariCOF outlooks, including the precipitation, drought and wet days/wet spells outlooks.