After uneventfully crossing the Atlantic Ocean, the system developed a well-defined circulation while in the Caribbean Sea on September 20 and was then classified as a tropical depression.

After weakening over the Yucatan Peninsula, Hermine restrengthened to near-hurricane status again over the Gulf of Mexico before making landfall in the Mexican state of Veracruz.

A tropical wave emerged into the Atlantic from the west coast of Africa on September 11, though the system lacked a well-defined circulation.

The tropical wave tracked westward for several days with minimal development, until reaching near the Lesser Antilles where a low-level cloud banding feature appeared, along with an increase in central convection.

[1] It is estimated that Tropical Depression Eleven developed at 1200 UTC on that day, while it was centered about 240 miles (390 km) south of Kingston, Jamaica.

[5] The storm weakened somewhat over the Yucatán Peninsula, and sustained winds were 50 mph (80 km/h) when Hermine emerged into the Bay of Campeche on September 23.

[1] Although several computer models suggested a northward turn,[6] Hermine drifted southwestward, possibly due to high terrain over Mexico.

[7] Hermine attained its peak intensity with winds of 70 mph (110 km/h) and a minimum pressure of 993 mbar (29.3 inHg) early on September 24, as measured by reconnaissance aircraft.

[1] On September 21, the government of Belize issued a gale warning, as well as a hurricane watch, for most of the eastern coast of the country.

[11] While crossing the southern Yucatán Peninsula, Hermine brought locally heavy rains and strong winds to eastern Mexico and much of Belize – then a colony of the United Kingdom.

[14] Tropical Storm Hermine and the remnants caused heavy rainfall across along most of the southern and eastern parts of Mexico.

[16] Two small dams broke due to excessive rains near Tuxtla Gutiérrez, prompting the evacuation of 2,000 residents in nearby areas.