Mexico: Tropical Storm John tracking northwestward off the coast of Michoacan State early Sept. 27 /update 6

Tropical Storm John is tracking northwestward off the coast of Michoacan State, Mexico, early Sept. 27. The storm previously made landfall as a Category 3 hurricane south-southwest of Marquelia, Guerrero State, late Sept. 23, before weakening into a tropical depression and moving back out into the Pacific Ocean Sept. 24. The system then reformed over open water Sept. 25 before heading back towards western Mexico. As of 03:00 CST, the system's center of circulation was approximately 75 km (50 miles) west-southwest of Lazaro Cardenas, Michoacan State.

Forecast models indicate that John will make landfall near Maruata in Michoacan State in the coming hours. After landfall, John is forecast to weaken into a tropical depression as it tracks northwestward over the coasts of western Guerrero, Colima, and southeastern Jalisco through Sept. 27 before transitioning into a post-tropical cyclone as it tracks west-northwestward back into the Pacific Ocean early Sept. 28. Some uncertainty remains in the track and intensity forecast, and changes could occur over the coming days.

As of early Sept. 27, authorities have issued the following watches and warnings:

• Tropical Storm Warning: Punta Maldonado to Manzanillo

Tropical storm conditions are ongoing along the coast in the warning area and are expected to continue over the coming hours. Storm surge is likely to produce coastal flooding near and to the east of where the center makes landfall. Near the coast, the surge will be accompanied by large waves.

Forecast models indicate that the system will produce additional rainfall totals of 25-50 cm (10-20 inches) across parts of Guerrero and Michoacan states through Sept. 27. Additional rainfall amounts of 5-10 cm (2-4 inches) with localized totals up to 15 cm (6 inches) are forecast across Colima and western Oaxaca states. Swells from the system will continue affecting the coast of southern and southwestern Mexico through Sept. 28. The swells may cause dangerous surf and rip currents.

Several ports are closed to small vessels ahead of John's approach, including Acapulco, Puerto Marquez, and Zihuatanejo in Guerrero State and Lazaro Cardenas in Michoacan State. Authorities have opened hundreds of shelters across parts of Guerrero and Michoacan states, and civil protection authorities have issued the highest red-level alert in Guerrero. Schools are closed across parts of Colima, Guerrero, Michoacan, and Oaxaca. Acapulco International Airport (ACA) is closed until further notice.

Flooding, landslides, blocked roads, power outages, and other associated disruptions have been reported across parts of Guerrero and Oaxaca since the storm first made landfall. Authorities have reported at least seven storm-related fatalities in Guerrero and three fatalities in Oaxaca. At least 300 homes have been flooded in parts of Guerrero State. At the height of the storm, more than 206,000 people in Guerrero and Oaxaca were without power. Additional adverse weather associated with the storm will likely exacerbate the situation in affected areas.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, additional flash flooding, and landslides are possible.

Inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding may increase the incidence of insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.