Hurricane Hanna downgraded to tropical storm as it lands in virus-hit Texas

HOUSTON — The first Atlantic hurricane of 2020 was downgraded to a tropical storm on Sunday after it swept into coronavirus-hit Texas, bringing heavy rain, storm surges and potentially life-threatening flash flooding.

The Category 1 storm was downgraded by the US National Hurricane Centre (NHC) to a tropical storm at around 06:00 GMT but it was still packing winds of around 115 kilometres per hour.

"Hanna is expected to produce heavy rains across portions of southern Texas and north-eastern Mexico. These rains will result in life-threatening flash flooding," and some river flooding, meteorologists said earlier.

There were no immediate reports of casualties or widespread damage.

But meteorologists warned a "life-threatening storm surge" could reach 1.8 metres in some areas, while the storm was forecast to drop up to 45 centimetres of rain through Monday on south Texas and Mexico.

"My Administration is closely monitoring Hurricane Douglas off Hawaii & Hurricane Hanna, which has now made landfall in Texas," President Donald Trump tweeted.

"We continue to coordinate closely with both states — listen to your emergency management officials... to protect your family & property!"

Damage appeared limited in the immediate aftermath of Hanna's landfall on Padre Island at around 5pm (22:00 GMT), with some isolated flooding and power outages.

Images captured by CBS showed roads and a caravan park in the coastal city of Corpus Christi strewn with debris and downed trees.

Some motorists even braved flooded roads, while one hardy storm-watcher was seen calmly taking pictures of the beach from a wind-swept promenade.

Local authorities were readying for the possibility of tornadoes springing up overnight in some coastal areas, according to local news reports, as the American Red Cross opened three shelters across the state in preparation.

Images shared by the National Weather Service office in Corpus Christi showed water lapping at the city's bayfront Art Museum of South Texas. 

Texas State Aquarium said it would be closed following some storm damage. 

Hanna hit as Texas faces a huge surge in COVID-19 infections, with officials instituting a state-wide mask mandate to curb the spread of the disease.

Hanna was about 112 kilometres south of Corpus Christi when it made landfall, with the city of 325,000 a virus hotspot.

The US is the hardest-hit country in the coronavirus pandemic, with some 4.2 million cases, and authorities will have to figure out how to safely shelter residents forced out of their homes by future hurricanes this season. 

Hanna was forecast to move inland over south Texas on Saturday night, and into north-eastern Mexico on Sunday.

Two other storm systems were churning Saturday: Pacific Hurricane Douglas, bearing down on the Hawaiian islands, and Tropical Storm Gonzalo in the Atlantic, near the Windward Islands.

Douglas has weakened to a Category 1 storm with wind speeds of 144 kilometres per hour.

The NHC said the storm will be near the main Hawaiian Islands Saturday, moving over parts of the state Sunday and Monday, bringing high winds, heavy surf, and rainfall of up to 25 centimetres.

A hurricane warning was in effect in Oahu.

Meanwhile, Venezuela warned of heavy rains and gusting winds as Gonzalo moved west across the Caribbean.

Big waves had started to pound the eastern coast and power was knocked out in some areas Saturday, Venezuelan media reported.