Tropical Depression Harvey redeveloped Wednesday morning in the Bay of Campeche and is forecast to roar into the Texas or Louisiana coast as a hurricane later this week.

"We are anticipating Harvey being a hurricane at landfall," the National Hurricane Center said.

Rainfall from Harvey could cause life-threatening flooding across the region, the hurricane center predicted.

A hurricane watch has been posted along the Texas coast from near Port Mansfield to San Luis Pass.

Harvey is expected to produce total rain accumulations of 10 to 15 inches with isolated maximum amounts of 20 inches over the middle and upper Texas coast and southwest Louisiana through next Tuesday. Heavy rainfall could begin as early as Friday morning.

Houston, the nation's fourth-largest city, is in the cross hairs for the heavy rain.

At Wednesday's City Council meeting, Houston Mayor Sylvester Turner said now is the time for citizens to prepare, encouraging everyone to make an emergency kit, minimize travel and monitor conditions, according to KHOU-TV.

Whether Harvey makes landfall as a strong tropical storm or a Category 1 hurricane may not make a huge difference in terms of impact, AccuWeather said, since days of torrential rain are the main threat.

A storm surge of up to six feet could also inundate coastal areas, prompting a storm surge watch to be posted for much of the Texas coast. This marks the first time this new product has been issued by the hurricane center.

As of 2 p.m. ET, Harvey had winds of 35 mph and was stationary. The center of the depression was located about 470 miles southeast of Port Mansfield, Texas.

A depression becomes a storm when its sustained winds reach 39 mph. It then becomes a hurricane when winds reach 74 mph.