Mexico: Adverse weather conditions forecast to continue across much of the country through at least Oct. 21 /update 1

Adverse weather is forecast across much of Mexico through at least Oct. 21. A combination of meteorological phenomena is expected to generate heavy rainfall, thunderstorms, and strong winds across many parts of the country over the coming days. A cold front over eastern Mexico and a tropical wave moving over southeastern Mexico will bring heavy rainfall and thunderstorms to eastern, southern, and southeastern regions over the coming days. The cold front will also bring strong winds to eastern and northern regions, and the cold air mass behind the front will lead to a drop in temperatures across much of the country, with overnight lows of below 0 C (32 F) possible in mountainous parts of northern Mexico. Moisture from the Pacific Ocean and Gulf of Mexico is expected to generate showers and storms across central, southern, and western regions. A second cold front is expected to move into northwestern Mexico over the coming days.

Rainfall totals of 7.5-15 cm (3-6 inches) are forecast across parts of Chiapas, Oaxaca, Quintana Roo, Tabasco, and Veracruz states Oct. 17-20, Tamaulipas Oct. 17, and Campeche and Puebla Oct. 19-20. Rainfall totals of 2.5-7.5 cm (1-3 inches) are forecast across other parts of eastern and southern Mexico Oct. 17-20 and northeastern and western Mexico Oct. 17. Heavy downpours may trigger flooding in low-lying areas and landslides on unstable slopes across parts of the affected area over the coming days. Strong winds gusting up to 80 kph (50 mph) may generate dust storms over northern and north-central regions.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Further landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.

The severe weather could contribute to transport disruptions throughout affected regions. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather may also trigger flight delays and cancellations at airports across the affected region. Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas with heavy rainfall and potential track inundation.