Overview
- Mexico’s weather service says the stationary Front 19 continues to drive heavy rain over Chiapas, Campeche, Yucatán and Quintana Roo but is expected to stop affecting the country by the end of the day.
- A new frontal system approaching the north and northeast is triggering wind advisories of 30–50 km/h in Coahuila, Nuevo León and Tamaulipas, with hard freezes forecast in northern highlands down to −10 to −5 °C in Chihuahua and Durango.
- Low‑pressure channels with Pacific and Gulf moisture are producing showers across the west, center, east, south and southeast, including Michoacán, Guerrero, State of Mexico, Mexico City, Tlaxcala, Puebla, Veracruz, Oaxaca and Tabasco.
- Argentina’s SMN issued yellow alerts for storms across the AMBA and parts of Buenos Aires, Mendoza, La Pampa, Neuquén and Río Negro, warning of lightning, hail, gusts up to 70–80 km/h and 20–50 mm of rain, with a brief hot spell near 34 °C expected by Friday.
- Peru’s Senamhi confirms the astronomical start of summer on December 21, advising precautions for higher temperatures and stronger ultraviolet radiation.