QCOSTARICA – The national weather service, the Instituto Meteorológico Nacional (IMN), confirmed the announcement by the United States Oceanic and Atmospheric Administration Agency (NOAA) that the La Niña phenomenon could consolidate this month.
Under its influence, the rains intensify on the Pacific coast and the Central Valley, while the Caribbean and the north, on the contrary, will be drier.
“With regard to the La Niña early warning system, the IMN went from ‘surveillance’ to ‘warning’ status, reaching 87% the probability of development of this phenomenon,” said meteorologist Luis Fernando Alvarado.
He added that in less than two weeks the effects will begin to be felt in our country. “The warning is especially for the remaining months of the rainy season, not only because of the intensity and probable prolongation, but also because of the effects of the hurricanes that would develop in the Caribbean Sea,” he said.
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This second wave is expected to last until March 2022 and be less intense and prolonged than the one between August 2020 and May of this year. Since last February, meteorologists began to glimpse the possibility of a repetition of this phenomenon, directly related to temperature indicators of the sea and the atmosphere. In the case of the ocean, it is required that the Pacific index remained the same or 0.5 ° C lower than normal and that the forecast indicates that it will remain in that condition for at least the next three months, which it did.
In recent La Niña events, there has been a strong storm associated with low pressures or cyclones in the Caribbean Sea, the most recent were those caused by the impact on the isthmus of hurricanes Eta and Iota in full swing of the previous La Niña event.
Other repercussions include lower-than-normal temperatures, as well as a more intense and prolonged rainy season. “It is very likely that the rainy season in the Pacific and the Central Valley will intensify and that, on the contrary, the deficit will continue on the Caribbean side, with the possibility of a meteorological drought,” said Alvarado, coordinator of the IMN climatology unit.
Under the effects of La Niña, the dry season in the Pacific and Central Valley will present less hot conditions than normal and even days with surprising downpours are expected. The IMN has kept the National Emergency Commission (CNE), as well as entities such as the Ministry of Agriculture and Livestock and Aqueducts and Sewers, aware of this forecast.
“It cannot be ruled out that smaller space-time scale atmospheric oscillations, such as Madden-Julian and Kelvin, may positively or negatively interfere with these weather patterns,” says the IMN.