Acknowledging that Harris County has been "fortunate" so far, emergency officials are warning residents to remain vigilant of the threat of tornadoes as Harvey continues to move through the area.

"We've had a lot of warnings this morning—10, 15 tornado warnings this morning—they've been in that Brazoria, Fort Bend County corridor, but as that band moves up into Harris County, we could see some tornados," warned Jeff Lindner with the county's Flood Control District and the Office of Emergency Management.

Lindner noted that the tornadoes are fast-moving and pointed out that radar sweeps can be several minutes behind, so residents should be prepared to take shelter with little notice.

Any tornadoes that do strike Harris County are expected to be weaker EF-0 and EF-1 tornadoes, Lindner said.

"The longevity of this is going to go through the weekend and into next week," Linder added. "We're just into the very, very start of this event for us.

With forecasts calling for Harvey to linger over southeast Texas for as many as five days, crews with the county and the city of Houston have worked to clear out storm drains and set up barricades at common high-water spots.

No evacuation orders have been issued for Houston.

From ABC 13