TRENTON -- A pair of New Jersey National Guard helicopters and crew are Texas bound Wednesday morning to help with the rescue and recovery effort in the wake of the devastation of Hurricane Harvey, Gov. Chris Christie announced Tuesday night.

The governor signed off on the state's National Guard sending eight crew members, including four pilots and four crew chiefs, along with two Blackhawks.

"With real-life experience and top-notch training, the emergency response members from our Joint Base and our State Police are invaluable resources that will help lift Texas out of the devastation and despair caused by Hurricane Harvey," Christie said.

The crew and equipment is scheduled to arrive in Dallas by Friday, the governor's office said.

New Jersey's emergency response team deployed Sunday to help with the recovery crossed into Texas overnight, according to NJ Task Force 1's Facebook page.

"I will continue to make good on my promise to authorize and deploy every available resource possible for the tens of thousands of disaster victims who need rescuing, and who will need our recovery assistance in the days and weeks ahead," Christie said.

The nation's fourth-largest city remained mostly paralyzed Tuesday by one of the largest downpours in U.S. history. And there was no relief in sight from the storm that spun into Texas as a Category 4 hurricane, then parked over the Gulf Coast. With nearly two more feet of rain expected on top of the 30-plus inches in some places, officials worried that the worst might be yet to come.

The Houston metro area covers about 10,000 square miles, an area slightly bigger than New Jersey. It's crisscrossed by about 1,700 miles of channels, creeks and bayous that drain into the Gulf of Mexico, about 50 miles to the southeast from downtown.

The storm is generating an amount of rain that would normally be seen only once in more than 1,000 years, said Edmond Russo, a deputy district engineer for the Army Corps of Engineers, which was concerned that floodwater would spill around a pair of 70-year-old reservoir dams that protect downtown Houston.

The Associated Press contributed to this report.

Matt Arco may be reached at marco@njadvancemedia.com. Follow him on Twitter @MatthewArco or Facebook.