The Dirección Meteorológica de Chile (DMC), Chile's national weather service, issued an aviso (advisory) for likely thunderstorms between the Valparaíso and Biobío regions, according to CNN Chile. The storms are expected mainly between the afternoon and evening of Monday, October 26.
According to that outlet, the synoptic condition behind the event is an upper-level trough, meaning a disturbance in the upper layers of the atmosphere. The advisory also warns of a chance of hail.
The agency listed the exposed areas in each region. In Valparaíso, the storms would affect the Andean foothills, the foothill valleys and the Andes mountains. In the Región Metropolitana (the Santiago Metropolitan Region), they would affect the valley, the foothills and the Andes mountains.
In O'Higgins, Maule, Ñuble and Biobío, the advisory covers a wider band: the Coastal Range, the valley, the foothills and the Andes mountains. In total, six regions in central and south-central Chile are included.
The DMC explained that an aviso means a forecast of "weather phenomena with a moderate degree of severity, potentially hazardous." On its risk communication scale, it ranks below an alerta (alert) and an alarma (alarm).
The source does not give rainfall amounts, specific times for each comuna (municipality), or any measures by other emergency agencies.
Meteorología advised the public to stay informed, especially people doing activities exposed to weather risks on Monday afternoon and evening.
