Harvey's rain 'unprecedented', situation may become more alarming: National Weather Service

United States National Weather Service called the catastrophic deluge due to Hurricane Harvey in Houston as "unprecedented" and warned that the situation may become more alarming if a record-breaking 50 inches of rain falls on parts of Texas in coming days.

The rainfall may intensify an already dangerous situation, as many east Texas rivers and bayous is flowing above the danger level after the Harvey's rain.

"The breadth and intensity of this rainfall are beyond anything experienced before. Catastrophic flooding is now underway and expected to continue for days,' the weather service said.

As per the Washington Post, more than 3,000 national and state guard troops have being deployed to carry out relief and recovery operations in the city and surrounding areas.

Texas Governor Greg Abbott, earlier said that the perpetual rain and dire flash flooding has produced the strongest storm the state has witnessed in past 50 years.

Abbott said this in a press conference, though he did not confirmed the total number of people killed in the deluge nor the number of evacuations.

However, the National Weather Service has said there have been reports of as many as five deaths.

Meanwhile, President Donald Trump will visit Texas on Tuesday to take a stock of the situation and review state's efforts to recover from Hurricane Harvey.

As per the CNN, White House press secretary Sarah Huckabee Sanders informed this and said that, "We are coordinating logistics with state and local officials, and once details are finalized, we will let you know."

"We continue to keep all of those affected in our thoughts and prayers," she added.

The exact location is not yet decided, but the president is expected to travel away from the storm zone, avoiding the most hard-hit areas, reported the CNN.

Trump on Sunday lauded the government agencies' "coordinated" response to Hurricane Harvey.

"Great coordination between agencies at all levels of government. Continuing rains and flash floods are being dealt with. Thousands rescued. Many people are now saying that this is the worst storm/hurricane they have ever seen. Good news is that we have great talent on the ground," Trump said in a series of tweets.

More than 1,000 people had been rescued overnight due to record flooding in the sprawling Houston area, CNN quoted meteorologist Jeff Lindner with Harris County's Flood Control District as saying.

According to local media reports, the storm hit southeastern Texas as a Category 4 hurricane, but wind speeds have since slowed down and it is now a tropical storm.

The storm is Trump's first major natural disaster in office and will be the first major hurricane to hit the U.S. since 2005.