Which regions does it impact and how should regions prepare?

The National Unit for Disaster Risk Management (UNGRD) announced the preparation and readiness actions to face the season of less rain that has occurred since the middle of the year in the country.

The period of this season runs from mid-June to mid-September and, despite a decrease in the intensity and frequency of rainfall, this does not mean that it will stop raining completely at a national level or in the regions most prone to a decrease in rainfall.

Given this situation, the national territory is historically more prone to forest fires, rising temperatures, frost, droughts and water shortages at this time.

Which regions are affected by the dry season?

Normally, since mid-June there is a decrease in rainfall in much of the Andean region, in central and northern areas of the Caribbean region and in some areas of the Orinoquía. A situation that becomes more noticeable during the months of July and August.

However, in some areas of the country there may continue to be excessive rainfall, flash floods, landslides, torrential floods, gales, thunderstorms, hail and fog.

It is worth highlighting that in addition to the conditions typical of this time, there is an Atlantic hurricane season that is warned to be very active this year and that usually generates rain in the northern region of the country. The forecast indicates that category events would amount to 21 this year, in contrast to the annual average which is usually 14.

Of these 21 tropical cyclones, 11 are expected to become hurricanes when the annual average of hurricane occurrence is seven and, in turn, it is likely that at least five of them will become systems of category 3, 4 or 5 or higher. A complex scenario considering that these are the categories where most damage and losses usually occur.

In addition, the arrival of a La Niña phenomenon is also expected during this second half of the year. According to IDEAM forecasts, there is a 65 percent probability of the arrival of La Niña between July and September. A time when its influence on the region’s climate will begin to be more significant.

And, although there is still no complete certainty that this will be the prevailing scenario – entities such as the World Meteorological Organization (WMO) still foresee it as equally likely (50 percent probabilities) that neutral conditions will persist or that they will evolve towards a La Niña episode between June and August 2024 – the truth is that the cooling that is being seen in the oceans is already beginning to cause concern about its possible consequences.

According to Catalina González-Arango, a professor in the Department of Biological Sciences at the University of Los Andes who has more than 15 years of experience in the study of the paleoecological and paleoclimatic history of tropical ecosystems in northern South America, La Niña is the cold phase of the ENSO phenomenon (El Niño-Southern Oscillation), an oceanic phenomenon in which the surface of the eastern equatorial Pacific Ocean cools more than usual.

“The La Niña phenomenon is generally expressed in Colombia as increased rainfall and decreased temperatures, especially in the Andean, Pacific and Caribbean regions,” explains González.

That is why IDEAM has warned that this phenomenon, which produces changes in tropical atmospheric circulation (such as winds, pressure and precipitation), can have a significant impact both on the current dry season and on the second wet season that usually takes place in the country between September and November. That is to say, given this reality, this season of less rain could have more precipitation events than normal.

“With the guidelines we issued at the National Unit, we invite local authorities, entities of the National Disaster Risk Management System and communities to prepare and be aware of the forecasts, work on prevention and get ready for the heavy rains that may occur at the end of the year with the possible influence of the La Niña phenomenon,” said Carlos Carrillo Arenas, general director of UNGRD.

Recommendations to prepare for the arrival of the less rainy season

UNGRD has asked mayors, governors and territorial councils for disaster risk management to begin monitoring areas of vegetation cover that are prone to the formation of forest fires and to identify areas susceptible to flooding and landslides, and agricultural land that may suffer damage from high or low temperatures.

In addition, it was requested to review and update the contingency plans for the La Niña phenomenon, considering the risk scenarios that may arise during the season of less rain in the middle of the year and to articulate the departmental and municipal strategies for emergency response.

The entity also requested that critical points be identified by risk scenario, that monitoring and follow-up be carried out in urban and rural areas, and that actions be taken to guarantee the protection of the life and safety of residents, pets and production animals, and wildlife located in high-risk areas.

Finally, the UNGRD requested to socialize with the communities the contingency plans for the phenomena associated with the season of less rain and the possible La Niña phenomenon, and to promote the formulation and updating of family, communal and community emergency plans with emphasis on the evacuation routes, meeting points and emergency lines, among other actions.

EDWIN CAICEDO

Environment and health journalist

@CaicedoUcros