CariCOF Climate Outlooks

The Caribbean Climate Outlook Forum (CariCOF) Climate Outlooks for the Caribbean are prepared by the Caribbean Institute for Meteorology and Hydrology with contributions from most of the Caribbean region’s Meteorological Services. These outlooks have been produced each month since February 2012 by combining global, regional and national forecasts and expert interpretation.

As of May 2017, the procedure to generate seasonal forecasts and produce climate outlook products derived from those seasonal forecasts goes as follows.

National and region-wide forecasts are produced using the Caribbean Outlook Generator (CAROGEN). CAROGEN is an automation platform that produces a regionally agreed set of ensemble experiments run with the International Research Institute for Climate and Society (IRI)’s Climate Predictability Tool (CPT, which was integrated into CAROGEN). The platform utilises its own daily and monthly precipitation and temperatures, as well as, input data from WMO Global Producing Centres for Long-Range Forecasting (GPCs) – some of which accessed through the IRI’s Data Library.

0-month and 3-month lead, regional, objective consensus forecast maps are considered together with global dynamical climate models. Global forecasts that are examined include those from the IRI, the U.K. Met Office, ECMWF, Météo-France, NOAA Climate Prediction Center (CPC), the World Meteorological Organization (WMO) Lead Centre for Long-Range Forecast Multi-Model Ensemble (LC-LRF MME), the APCC, Japan Meteorological Agency (JMA), Environment and Climate Change Canada Canadian Meteorological Centre (CMC) and the North American Multi-Model Ensemble (NMME).

Probabilities for three-month rainfall totals and temperature averages are estimated for sub-regions based on the model outputs, the level of agreement between the different models and expert knowledge of the regional setting. In the majority of cases, and unless known deficiencies of the objective models are identified, the ensemble mean probabilities of each type of objective ensemble forecast is followed in the preparation of the draft, subjective consensus outlook maps.

The tercile-based consensus Precipitation Outlooks, and Minimum, Mean and Maximum Temperature Outlooks are then issued in the form of GIS map layers within CAROGEN at national level and, after post-processing using GIS scripts, at the CariCOF level.

These outlooks are given in the form of maps showing forecast probabilities for below, near, and above normal. The terciles (i.e. statistically the 33.3…rd percentile and the 66.6…th percentile) separate the possible outcomes into three categories which are historically speaking equally probable. The probabilities of the three categories add up to 100. These categories thus represent:

• Above Normal – Wettest Third of the Record
• Near Normal   – Middle Third of the Record
• Below Normal – Driest Third of the Record

The tercile probabilities are presented in the form:

Besides the generic RCOF outlook products, CariCOF produces a series of thematic or hazard-specific outlook products.

Drought Outlooks are issued in the form of a presentation that combines alert maps, with four categories of increasing alert level, with a narrative on recent and near-future drought conditions.

Another product, Wet Days and Wet Spells Outlooks, forecasts number ranges and frequency shifts in wet days and wet spells. It is issued in the form of a presentation that links the 0-month lead regional Precipitation Outlook, with the climatology and forecasts of wet days and wet spells, as well as expected climate impacts in the coming three months.

Finally, since May 2017, experimental Heatwave Outlooks have been produced and updated monthly during the warmest part of the year, i.e. from May to October.