Kalain Ho­sein

You may need to wait a bit longer if you’re wait­ing on the 2023 Dry Sea­son for dry weath­er. More above-av­er­age rain­fall is on tap for the Caribbean, and it all has to do with the tem­per­a­tures of the ocean in the Pa­cif­ic.

La Niña is a nat­ur­al weath­er-form­ing phe­nom­e­non that refers to the large-scale cool­ing of ocean sur­face tem­per­a­tures in the cen­tral and east­ern equa­to­r­i­al Pa­cif­ic oceans. It is gen­er­al­ly cou­pled with changes in winds, pres­sure and rain­fall glob­al­ly.

A La Niña gen­er­al­ly leads to more favourable con­di­tions for trop­i­cal storms and hur­ri­canes in the At­lantic, as well as wet­ter than av­er­age con­di­tions in the south­ern Caribbean, where T&T is lo­cat­ed.

An El Niño gen­er­al­ly has the op­po­site ef­fect, cre­at­ing a hos­tile en­vi­ron­ment for rain­fall and trop­i­cal ac­tiv­i­ty in the At­lantic, lead­ing to dri­er con­di­tions for the Caribbean.

The cur­rent La Niña event be­gan in 2020, which means 2023 will be­come the third con­sec­u­tive year of La Niña con­di­tions mak­ing this “triple-dip” the third time this has been since 1950.

The World Me­te­o­ro­log­i­cal Or­gan­i­sa­tion (WMO) El Niño/La Niña Up­date in­di­cates about a 75 per cent chance that La Niña will per­sist dur­ing De­cem­ber-Feb­ru­ary 2022/2023 and a 60 per cent chance dur­ing Jan­u­ary-March 2023.

For the Caribbean re­gion, the per­sist­ing La Niña has led to a wet sea­son char­ac­terised by above-nor­mal rain­fall, which is like­ly to con­tin­ue in­to what is usu­al­ly the dry sea­son.

The Caribbean In­sti­tute for Me­te­o­rol­o­gy and Hy­drol­o­gy, at their re­cent­ly con­clud­ed Caribbean Cli­mate Out­look Fo­rum, in­di­cat­ed that the prob­a­bil­i­ty of the re­gion ex­pe­ri­enc­ing above-nor­mal rain­fall in­to Jan­u­ary of next year is 45 per cent, while from Feb­ru­ary to April, there will be a 50 per cent prob­a­bil­i­ty of above-nor­mal rain­fall in the South­ern Caribbean.

This trend to­wards above-nor­mal rain­fall has al­ready led to record-break­ing lev­els of pre­cip­i­ta­tion in Trinidad and To­ba­go, with this No­vem­ber be­ing the wettest on record since 1946, record­ing dou­ble the av­er­age month­ly rain­fall to­tal for No­vem­ber.

La Niña is a nat­ur­al phe­nom­e­non.

But it is tak­ing place against a back­ground of hu­man-in­duced cli­mate change, which is in­creas­ing glob­al tem­per­a­tures, mak­ing our weath­er more ex­treme and af­fect­ing sea­son­al rain­fall pat­terns.

In T&T, cli­mate change has al­ready led to more ex­treme rain­fall, with an in­crease in ex­treme­ly wet days where rain­fall to­tals ex­ceed 25 mil­lime­tres.

How­ev­er, it’s not all wet weath­er across the globe.

In a state­ment, WMO sec­re­tary-gen­er­al Pro­fes­sor Pet­teri Taalas said, “This per­sis­tent La Niña event is pro­long­ing drought and flood con­di­tions in af­fect­ed re­gions. The in­ter­na­tion­al com­mu­ni­ty is es­pe­cial­ly con­cerned about the un­fold­ing hu­man­i­tar­i­an cat­a­stro­phe for mil­lions of peo­ple in the Horn of Africa, dri­ven by the longest and most se­vere drought in re­cent his­to­ry.”