KALAIN HO­SEIN

The Trinidad and To­ba­go Me­te­o­ro­log­i­cal Ser­vice (TTMS) is fore­cast­ing dry con­di­tions to spread across Trinidad and To­ba­go through April 2021.

Ac­cord­ing to the TTMS, most of Trinidad's north­ern half ex­pe­ri­enced bor­der­line dry to slight­ly dry con­di­tions based on rain­fall mea­sure­ments across the coun­try.  These mea­sure­ments were com­piled in­to the Stan­dard­ized Pre­cip­i­ta­tion In­dex and con­vert­ed in­to a map us­ing the TTMS' Dry­ness In­di­ca­tor.

Dur­ing the 90 days be­tween No­vem­ber 2020 and Jan­u­ary 2021, T&T's Dry­ness In­di­ca­tor ranged be­tween -0.5 to -1.0 across the north­ern half of Trinidad, with an area of -0.5 across south-cen­tral Trinidad.  Most lo­ca­tions across Cen­tral and South­ern Trinidad ex­pe­ri­enced near-av­er­age rain­fall with val­ues greater than -0.5.

The Standardized Precipitation Index (SPI) for November 2020 to January 2021 for T&T. Image courtesy Trinidad and Tobago Meteorological Service (TTMS).

The TTMS' Dry­ness Out­look from Feb­ru­ary through April 2021 in­di­cates bor­der­line dry to dry con­di­tions are like­ly to spread over larg­er ar­eas of the coun­try, with dry­ness lev­els strength­en­ing in some lo­ca­tions.  No­tably, all ar­eas across T&T, ac­cord­ing to the Met Of­fice, are like­ly to re­main be­low the dry-spell lev­el on the Dry­ness In­di­ca­tor, or less than -1.25 on the Stan­dard­ized Pre­cip­i­ta­tion In­dex.

The ex­pect­ed dry­ing is like­ly to in­crease bush and for­est fire po­ten­tial, es­pe­cial­ly dur­ing late Feb­ru­ary and March. Re­duced air qual­i­ty is al­so ex­pect­ed dur­ing bush-, grass-, for­est- and land­fill-fires.  This can neg­a­tive­ly af­fect per­sons with ex­ist­ing res­pi­ra­to­ry and oth­er ail­ments.

In the TTMS' Rain­fall and Tem­per­a­ture Out­look is­sued in Jan­u­ary 2021, the Of­fice called for "less dry than usu­al" with high chances for above-nor­mal rain­fall.  The Of­fice al­so in­di­cat­ed many sun­ny days with typ­i­cal dry sea­son weath­er ex­pect­ed, in­clud­ing typ­i­cal dust events, but more so dur­ing March and April.

What is the Dry­ness In­di­ca­tor?

The Dry­ness In­di­ca­tor is a tool for keep­ing track of the lev­el of dry con­di­tions, rain­fall deficit, and length of the dry pe­ri­od across Trinidad and To­ba­go.  It is based on the TTMS's Dry Spell and Me­te­o­ro­log­i­cal Drought Pol­i­cy, which us­es the Stan­dard­ized Pre­cip­i­ta­tion In­dex (SPI) to in­di­cate dry­ness lev­els.  The SPI is a sim­ple mea­sure of dry­ness based sole­ly on the to­tal rain­fall for a giv­en pe­ri­od, for ex­am­ple, over the last 60 days, com­pared with the long-term av­er­age rain­fall for that pe­ri­od.