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CORPUS CHRISTI, Texas (AP) — Tropical Storm Harvey continues to head back toward the Gulf of Mexico at a slow pace.

In its 10 p.m. CDT advisory, the National Hurricane Center reports the storm still has sustained winds of up to 40 mph and is centered 20 miles east of Victoria, Texas, about 120 miles southwest of Houston. It continues to creep to the east-southeast at 3 mph.

That means it remains virtually stalled near the coast and continues to drop heavy rain on the Houston and Galveston areas. In the past 48 hours, numerous spots in the region have measured more than 25 inches of rainfall.

The hurricane center says Harvey’s center was expected to drift off the middle Texas coast on Monday and meander offshore through Tuesday before beginning “a slow northeastward motion.”

The National Hurricane Center is offering no promises of relief from the epic rains unleashed on Southeast Texas by Tropical Storm Harvey.

In its 7 p.m. CDT advisory, forecasters said “little change in strength is forecast during the next 24 hours.” In fact, “some slight re-strengthening is possible after the center moves off the coast on Monday night and Tuesday.”

NWS meteorologist Patrick Burke says rainfall totals will end up around 40 inches or more for Houston on average, but some isolated spots will hit or exceed 50 inches.

Burke says, “We’re in kind of unprecedented territory with this storm.”

Local rainfall amounts of 50 inches would exceed any previous Texas rainfall record. The NWS says in a statement that “the breadth and intensity of this rainfall is beyond anything experienced before and is resulting in catastrophic flooding.”

Houston Mayor Sylvester Turner said that as of 5 p.m. on Sunday, Houston police and fire departments had received nearly 6,000 calls for rescues and had rescued more than 1,000 people. Many of these rescues were of people trapped on their roofs or in their attics.

Turner said that so far only one fatality has been confirmed – a woman who died Saturday evening after getting out of her car when it drove into a flooded street.

Turner said 22 aircrafts were working to help identify people stranded on roofs. Sixteen of those aircrafts are from U.S. Coast Guard.

In addition, 35 boats and 93 dump trucks were being used by the city for high water rescues.

The mayor also defended his decision not to order an evacuation.

Factors in his decision included not knowing where Harvey, when it was still a hurricane, was headed and the “crazy” logistics of trying to plan an evacuation of 2.3 million people within a couple of days.

Turner also cited the experience the city had when residents evacuated ahead of Hurricane Rita in 2005 and gridlocked local roadways, leaving many people in traffic for more than 20 hours as they fled the city and resulting in dozens of deaths. Rita had been predicted to hit Houston but ended up making landfall well east of the city.

“The decision that we made was a smart one. It was in the best interest of Houstonians,” he said. “It was the right decision in terms of their safety and always we must put the interests of the city and Houstonians first. That’s exactly what we did. We did what was the right thing to do.”

Turner said he has no concerns that the shelter that has been set up at the George R. Brown Convention Center will turn into New Orleans’ Superdome following Hurricane Katrina. At the football stadium, 30,000 evacuees spent days packed inside the sweltering dome with limited power and water and a roof that was shredded in the howling wind.

“I think in this city we know how to do it in such a way that is not chaotic. It’s respectful, it’s dignified,” Turner said.

Turner said he wants to transition people staying at the shelter to more suitable housing as quickly as possible.

Texas Gov. Greg Abbott says that the number of counties declared federal disaster areas from Tropical Storm Harvey and its aftermath has increased to 18.

Abbott said Sunday 12 counties have been added to an earlier federal disaster list of six. He said President Donald Trump has approved the increase in counties.

Also, 50 counties have already been declared state disaster zones, 30 earlier in the week and 20 on Saturday. Abbott says the counties under the federal and state declarations include Harris County, which encompasses Houston and has been experiencing severe flooding from torrential rains.

Nearly a quarter of Texas’ population lives in areas covered by a federal disaster declaration.

Harris County Judge Ed Emmett says that Ben Taub Hospital, the county’s public hospital, is being evacuated because flooding problems in the basement are disrupting power service.

Emmett overseas government operations in Harris County where Houston is located. He tells a news conference that evacuated patients are being taken to other area hospitals. It was not immediately known how many patients were being moved.

Both major airports in Houston have been closed amid severe flooding.

Abbott says the state has now activated 3,000 National Guard and State Guard members as a result of severe damage and flooding. Along with the guard, he says 500 vehicles and 14 aircraft have been put into service.

Abbott said there are no 250 highway closures around Texas.

He spoke at a news conference at the state emergency response center in Austin.

A Harris County official is asking members of the public who have a boat or a high water vehicle to help with efforts to rescue Houston residents whose homes have flooded in the torrential rains.

Harris County Judge Ed Emmett said at a news conference Sunday that the additional boats and vehicles that Texas is sending to the Houston area are not able to get to the area due to flooded roadways. He adds that vehicles the state previously sent are already being used to help rescue individuals.

Emmett, who oversees government operations in Harris County, where Houston is located, says, “We desperately need boats and high water vehicles … We can’t wait for assets to come from outside.”

Several hundred people have arrived at the downtown convention center the city of Houston has converted into a shelter after floodwaters inundated much of the city.

Ken Sandy has been designated shelter manager by the Red Cross. He said Sunday that his volunteers are prepared for 1,000 people at the George R. Brown Convention Center, and the center is big enough for them to expand if necessary. The center has 1.8 million square feet of space.

Volunteers are handing out towels to people entering the cavernous center. Cots have not yet arrived.

Authorities across Houston and surrounding Harris County are quickly opening shelters as the full toll of the flooding becomes clear and thousands of people evacuate their homes.

Police say a sinkhole has opened on a Texas highway about 25 miles southwest of Houston.

Rosenberg police on Sunday tweeted a photo of the gaping hole that spread across more than half of a two-lane highway – Farm-to-Market 762.

Water could be seen filling the sinkhole as pieces of highway asphalt hung from the edge of the damaged roadway.

Rosenberg police did not immediately provide additional details on the sinkhole, other than urging drivers to avoid the area. Police cars blocked off the highway.

(Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)

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