Mexico: Adverse weather conditions forecast across much of the country through at least Sept. 19 /update 1

Adverse weather is forecast across much of Mexico through at least Sept. 19. A combination of meteorological phenomena is expected to generate heavy rainfall and thunderstorms across many parts of the country over the coming days. Strong wind gusts, lightning, and hail are possible during storms. A cold front is forecast to move over northwestern Mexico Sept. 16-19, bringing showers, storms, strong winds, possible dust storms, and a drop in temperature in northern and northwestern regions. A tropical wave is expected to move over western regions Sept. 16-17, bringing heavy rainfall and thunderstorms to western Mexico. Another tropical wave will move over the Yucatan Peninsula and southern Mexico Sept. 17-19, bringing heavy rain and thunderstorms to eastern, southeastern, and southern regions. Low-pressure channels over central, eastern, northern, and western Mexico will bring further showers and storms to these regions.

Rainfall totals of 7.5-15 cm (3-6 inches) are expected over parts of Chiapas and Oaxaca states Sept. 16-19, Hidalgo and San Luis Potosi Sept. 16, Guererro and Veracruz Sept. 17-19, Tabasco Sept. 17-18, Michoacan Sept. 17, and Puebla Sept. 18-19. Rainfall totals of 2.5-7.5 (1-3 inches) are forecast across many other parts of the country over the coming days. Winds gusting up to 70 kph (43 mph) may cause dust storms in northern regions Sept. 16-19.

Heavy rainfall resulted in a landslide in the La Raquelito area of Naucalpan de Juarez Municipality in Mexico State Sept. 16 that buried a house and an elementary school. At least six people were killed and three others injured.

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.