Mexico: Adverse weather conditions forecast across much of the country through at least Sept. 23 /update 2

Adverse weather is forecast to continue across much of Mexico through at least Sept. 23. 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 tropical wave moving into the Pacific Ocean off western Mexico on Sept. 19 will bring heavy rainfall and thunderstorms to southern and western regions. Another tropical wave is forecast to approach the Yucatan Peninsula Sep. 19 and move over southern Mexico Sept. 20-22, bringing further showers and storms to southern parts of the country. One cold front will dissipate over northern Mexico Sept. 19, and another will approach the region Sept. 21. Low-pressure channels over the interior of the country will bring showers and storms to central, eastern, northern, and northeastern regions.

Rainfall totals of 7.5-15 cm (3-6 inches) are expected over parts of Chiapas State Sept. 19-22, Campeche Sept. 20-22, Quintana Roo and Yucatan Sept. 20, and Oaxaca, Tabasco, and Veracruz Sept. 22. 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 60 kph (37 mph) may cause dust storms in northern regions Sept. 19-22.

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.