President Trump wished Texas residents good luck ahead of Hurricane Harvey as he departed the White House on Aug. 25. (The Washington Post)

With Hurricane Harvey pounding Texas, President Trump is focusing more attention to the potentially catastrophic storm.

Known for live-tweeting news events, Trump waited until midday Friday before firing off a message to inspire public confidence.

“I have spoken w/ @GovAbbott of Texas and @LouisianaGov Edwards,” Trump tweeted just before noon. “Closely monitoring #HurricaneHarvey developments & here to assist as needed.”

That was quickly followed by another tweet showing a photo of Trump getting a briefing on the hurricane from senior aides. More tweets about the storm followed as the day progressed.

On Friday night, Trump announced he had signed a disaster proclamation at the request of Texas Gov. Greg Abbott (R) to provide immediate federal aid even before the brunt of the hurricane had been felt.

Hurricane Harvey made landfall on the night of Aug. 25 about 30 miles northeast of Corpus Christi as a Category 4 storm. (KIII 3 News)

Trump departed the White House on Friday afternoon with first lady Melania Trump for Camp David, the presidential retreat in Maryland, where he was maintaining contact with his homeland security team.

“Just arrived at Camp David where I am closely watching the path and doings of Hurricane Harvey, as it strengthens to a Category 3. BE SAFE!,” Trump tweeted Friday afternoon.

Saturday morning, the president again took to Twitter, praising FEMA Administrator Brock Long: “You are doing a great job - the world is watching! Be safe.”

He also responded to Sen. Charles E. Grassley (R-Iowa), who Friday morning urged him to stay on top of the hurricane: “@realDonaldTrump #hurricane keep on top of hurricane Harvey dont mke same mistake Pres Bush made w Katrina.”

Trump said: “.@ChuckGrassley - got your message loud and clear. We have fantastic people on the ground, got there long before #Harvey. So far, so good!”

He said he’s watching from Camp David and praised officials’ coordination.

“Closely monitoring #HurricaneHarvey from Camp David. We are leaving nothing to chance. City, State and Federal Govs. working great together!”

In the days leading up to the storm, the White House had exhibited little public urgency over what authorities projected as the first major hurricane to make landfall in the United States in a dozen years. The president began Friday morning with his usual stream of tweets about political grievances and settling scores with rivals, this time targeting Sen. Bob Corker (R-Tenn.).

“Tennessee not happy!” Trump proclaimed.

But as the president’s Friday posts make clear, it was the mood — and fate — of Texans in Harvey’s path that is the more pressing matter.

The Lone Star State was braced for a storm whose force the National Hurricane Center described as “astounding.” With winds greater than 140 miles per hour, Harvey struck north of Corpus Christi, the most powerful storm in the United States since Hurricane Wilma in 2005.

Since the federal government’s handling of Hurricane Katrina hobbled President George W. Bush’s second term, the politics of natural disasters have turbocharged the stakes for presidents, governors and mayors in coastal regions.

For a president who had no prior governing experience, the test is even more pronounced.

Trump has proposed slashing Federal Emergency Management Agency grant funding to states and municipalities by $667 million. Brock Long, FEMA’s director, was confirmed to the position in June after serving as Alabama’s emergency management director and working as a private consultant.

At the Department of Homeland Security, Elaine Duke has been serving as acting secretary since John F. Kelly moved to the White House as chief of staff late last month.

Homeland security adviser Thomas Bossert, who had worked in FEMA’s legislative division under Bush, emphasized that Trump has been fully briefed on the storm. In their meeting in the Oval Office on Friday morning, he said, Trump was focused on the safety of the up to 4.6 million people in the storm’s projected path and ensuring that federal agencies providing support have the resources they need.

White House aides have said Trump will visit Texas next week.

The memories of Katrina’s destruction and the Bush administration’s failure are vivid in Washington.

For those who served through major storms in the Bush and Obama administrations, the takeaway was clear: It is better to overprepare than to be caught off guard. Even if the federal response goes as well as could be expected, Mother Nature could still wreak significant death and destruction that could redound to the White House.

“The obvious lesson learned from Katrina is that strong executive involvement and oversight is necessary through the entire process,” said Steve Atkiss, who served under Bush as special assistant for operations.

During Katrina, the Category 5 hurricane in 2005 that flooded New Orleans, displaced thousands and killed more than 1,800 in Louisiana and Mississippi, Bush was at his ranch in Crawford, Tex. Though he cut short his vacation to return to Washington after water overwhelmed the levees in New Orleans, the crisis became a metaphor for a struggling administration preoccupied by faraway interventions in Iraq and Afghanistan.

Atkiss said that Bush was fully engaged and that the decision for him to view the destruction from the window of Air Force One, rather than visit the city, was made out of fear that his presence would become a distraction for federal law enforcement.

But Bush’s pronouncement that Michael D. Brown, then the head of his administration’s emergency-preparedness and response division, had done a “heck of a job” was met with widespread derision.

“Obviously, in hindsight, the optics were not good,” Atkiss said.

For the Obama administration, the lessons of Katrina were “really front and center for folks,” said Paul Rosen, who served as DHS chief of staff from 2015 to 2017. “I think Katrina was in the back of every emergency manager’s mind — FEMA, DHS, state and local — when it comes to disaster preparedness.”

Bossert agreed, saying the experience is seared into the “muscle memory” of those who lived through Katrina.

“We’ve gotten a lot better as a government,” he said.

The former officials said that coordination between the White House and federal agencies is crucial before, during and after a storm or other disaster, such as the BP oil spill off the Gulf Coast in 2010.

The role of the president, they said, is to use the bully pulpit to educate the public, emphasizing the danger but also managing the public reaction. Bush and President Barack Obama often visited the sites of major disasters in the days afterward to offer support — through federal resources and personal empathy to victims.

Trump visited FEMA’s headquarters in Washington on Aug. 4, receiving a briefing along with Cabinet members about the hurricane season. “Preparedness is an investment in our future,” the president wrote on Twitter after the visit.

In a tweet Thursday urging the public to “remember to ­#PlanAhead,” Trump included a 24-second video compilation of that visit, featuring dramatic music. Some Twitter users criticized the president for promoting a video that focused mostly on him.

Atkiss, though, said Trump will be well served by several top aides who have experience in dealing with emergency management, including White House deputy chiefs of staff Joseph Hagin, who served in the same role under Bush, and Kirstjen Nielsen, who served as special assistant to Bush for prevention, preparedness and response.

“There’s plenty of institutional knowledge and experience and successes and scars,” Atkiss said.

For presidents, storm politics go beyond the public’s measure of how well their administrations responded to the crisis. They are judged by which communities they visit, how long they spend on the ground and whom they meet.

In April 2011, then-Texas Gov. Rick Perry (R) blasted Obama for declaring Alabama an emergency disaster zone after tornadoes killed 200 while the president did not do the same for Texas when wildfires raged across 2 million acres that month.

Several months later, in September, Obama called Perry to express condolences for even more destructive fires — at a time when the governor was leading polls as the top prospective GOP challenger to Obama’s reelection the next year.

In the weeks leading up to the presidential election in 2012, New Jersey Gov. Chris Christie (R) was attacked by Republicans for embracing Obama’s support for federal aid — and a presidential visit — after Hurricane Sandy, which was technically a tropical storm when it made landfall in the United States but caused severe damage in New Jersey and New York.

Such political concerns are secondary at this point.

“Let’s hope this event fizzles and the forecasts are all wrong,” Bossert said. “But I don’t think that’s the right thing to hope for right now. We’re executing and we’re doing what it takes to save people’s lives.”

Terri Rupar contributed to this report.