Don’t leave home without your umbrella, as a tropical wave forming in the Carribean is expected to dump lots of water on us over the coming days. Photo Mario Cordero| La Nacion

Though expected to be nothing like Nate, a low-pressure system will affect the country over the next couple of days, enough for the Comisión Nacional de Emergencias (CNE) – national emergencies commission – to raise the alert from green to yellow for eight cantons of the Central Valley and the Pacific coast.

The national weather service, Instituto Meteorológico Nacional (IMN), explained the rains during the next few days will be heavier than the normal October rains, though lower than the category of a tropical depression and tropical storm like Nate.

The tropical wave that is looming could dump as much as 100 liters of water per square meter.

The yellow alert covers the entire Pacific coast – north, central and south – while the Central Valley remains on green alert, with the exception of Acosta, Aserrí, Puriscal, Turrubares, Dota, Tarrazú, León Cortés and Desamparados, cantons that were greatly affected by Nate on October 4 & 5, which is on yellow alert.

A low-pressure system is described as a disturbance that produces atmospheric instability by facilitating the development of clouds which in turn, encourage rainfall.

In this type of phenomena, the winds circulate counterclockwise and are loaded with moisture. Both conditions, mixed with ground heat and the ambient temperature provoke the development of increasingly intense and dangerous clouds, explained Juan Carlos Fallas, director of the IMN.

The concern of the IMN and the CNE is that the cantons declared on alert have soils saturated with water, said the director of the IMN, in a press conference on Monday at noon. He emphasized that the southern zone (Corredores, Osa, Golfito, Coto Brus) is the most prone to flooding.

He added that, in other circumstances, the expected damage would be less burdensome, but because of the rainfall that has been falling for months in most of the country, he described the effects of the storm as dangerous.

The (IMN) expects the effects to prevail until Wednesday or Thursday and as the system moves it will update the alerts and in which areas.