Mexico: Hurricane John tracking northward toward Guerrero State late Sept. 23 /update 1

Hurricane John is tracking northward in the eastern Pacific Ocean toward the southern coast of Mexico late Sept. 23. As of 21:00 CST, the system's center of circulation was approximately 20 km (15 miles) west of Punta Maldonado, Guerrero State.

Forecast models indicate that John will make landfall over far southeastern Guerrero State over the coming hours before weakening rapidly into a tropical storm. The system will then transition into a post tropical cyclone with tropical depression strength winds and dissipate as it tracks north-northwestward across the eastern part of Guerrero State through late Sept. 24. Some uncertainty remains in the track and intensity forecast, and changes could occur over the coming hours.

As of late Sept. 23, authorities have issued the following watches and warnings:

• Hurricane warning: east of Acapulco to Bahias de Huatulco

• Tropical storm warning: east of Bahias de Huatulco to Salina Cruz

Hurricane and tropical storm conditions are ongoing within portions of the hurricane and tropical storm warning areas respectively. Wind speeds atop and on the windward sides of hills and mountains are often up to 30 percent stronger and could be even greater in elevated areas.

Forecast models indicate the system will produce rainfall totals of 15-30 cm (6-12 inches) with localized higher amounts of up to 38 cm (15 inches) across coastal areas of Chiapas State, and totals of 25-50 cm (10-20 inches) with localized higher amounts up to 76 cm (30 inches) in areas along and near the coast of Oaxaca State to southeast Guerrero through Sept. 26.

A life-threatening storm surge, with large and destructive waves, will probably produce significant coastal flooding near and to the east of where the center makes landfall. Swells from the system will continue affecting the coast of southern Mexico over the coming days. The swells will likely cause life-threatening surf and rip current conditions.

Authorities have issued a red alert (highest level on a five-tier scale) for southeastern Guerrero and southwestern Oaxaca states and an orange alert for the rest of both states; residents should seek shelter until authorities give the all clear. Schools are closed in parts of Oaxaca and Guerrero states.

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

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase 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.