By Kimberly Ramkhalawan
October 19, 2021
With just a few weeks before the official end of Hurricane Season 2021, regional Meteorological officers are forecasting a second consecutive year of La Niña which they say we can expect to continue into the 2022 Dry Season.
La Niña can help make atmospheric conditions more favourable for tropical cyclones (tropical depressions, tropical storms and hurricanes) and often enhances rainfall activity in the following dry season. And while La Niña trends show it to occur every three to five years, it can occur consecutively ever so often, while some events occur over period of nine to twelve months, it can last for up to two years.
According to the Trinidad and Tobago Meteorological Office, which utilizes the El Niño-Southern Oscillation (ENSO) Outlook to indicate whether there is a probability of approximately 50 percent chance or greater for development of La Niña or El Niño, this year shows favour once again toward La Niña. The local Met Service says La Niña often proves to be its strongest during the period November to February, when conditions show to be wetter than usual.
It says this occurs because ‘La Niña favours upward moving air in the Caribbean region and tends to be associated with reduced wind shear; thus making it easier for rain producing clouds to form. The local atmospheric readjustments most often triggered by La Niña are an increase in the frequency of visits to our region by migrating shear lines or zones of low level convergence. These are due to fragments of, or decaying elongated cold fronts reaching as far as the southern Caribbean region. This often results in cooler conditions, especially colder nights. La Niña typically peaks during December to February. It is likely that at its peak, the current La Niña will be moderate to strong’.
On October 21, the National Oceanic and Atmospheric Administration (NOAA)’s Climate Prediction Center will announce the precipitation outlook extending from December 2021 through February 2022.