Powerful winds, storm surges and lashing rains are forecast to hammer a 325km stretch of coast between Mandvi in India's Gujarat state and Karachi in Pakistan.

Classified as a very severe cyclonic storm, Biparjoy is expected to make landfall around Thursday evening between Mandvi in India's Gujarat and Karachi in Pakistan.

Works Minister Alexander Nanta Linggi says the storm affected 29 schools in the national capital.

Rescue teams, including divers, were working in the region, the county says, although no deaths or injuries have been reported.

This is only the third time New Zealand has declared a state of emergency – the other two were the 2019 Christchurch attacks and 2020 Covid pandemic.

Tornado watches and severe thunderstorm warnings were in effect across much of Louisiana, Mississippi, Alabama and Georgia, along with flood watches posted along the southern fringe of that zone.

The US government has called Southwest Airlines' meltdown a system failure and vows action.

Officials in Erie county in western New York – the area of the country hardest hit by the massive winter storm – have lifted their death toll to 37, taking the national total to at least 59.

US President Joe Biden has approved an emergency declaration for New York state, freeing up funds to help it recover from the disaster.

In New York state, authorities have described ferocious conditions, with bodies being discovered in vehicles and under snow banks, and emergency personnel going 'car to car' searching for more motorists – alive or dead.

Heavy snow, howling winds and air so frigid it instantly turned boiling water into ice took hold of much of the nation, including normally temperate southern states.

The HTMS Sukhothai warship, a US-made corvette in use since 1987, capsized in the Gulf of Thailand after being knocked over by 4 metre waves and strong winds.