"Today's search operations have been suspended due to bad weather. All planes are returning to Perth & ships are leaving search area," the Australian Maritime Safety Authority (AMSA) tweeted.
Six military planes from Australia, China, Japan and the United States were flying sorties along with five civil aircraft, scouring two areas in the remote southern Indian Ocean covering a cumulative 78,000 square kilometres.
Five ships were also in the search zone, including Australia's HMAS Success and Chinese vessels Xue Long, Kunlunshan, Haikou and Qiandaohu.
Earlier Thursday, Australia's Bureau of Meteorology warned of impending thunderstorms and high winds in the search area 2,500 kilometres (1,550 miles) southwest of Perth.
Read: Missing MH370 jet's black box 'chirps' may go silent around mid-April
Towering waves and gale force winds are routinely whipped up in the desolate area where the search is being conducted, with operations also suspended on Tuesday.
Dozens of floating objects detected at sea provided fresh evidence on Wednesday that the difficult search for Flight MH370 debris was on course, as US lawyers fired the first salvo in an expected barrage of lawsuits on behalf of grieving families.
Satellite Image. Credit: Ministry of Science, Technology and Innovation (Malaysia)
Malaysia said satellite images taken in recent days showed "122 potential objects" in the remote southern Indian Ocean, a discovery likely to energise an international effort to recover suspected debris from the missing plane that has been frustrated by stormy weather.
Transport minister Hishammuddin Hussein cautioned that it was impossible to determine whether the objects were related to the Malaysia Airlines Boeing 777 which crashed on March 8 with 239 people aboard after it mysteriously disappearing.
"Nevertheless, this is another new lead that will help direct the search operation," he told a daily press briefing, calling it "the most credible lead that we have".
The images were provide by European aerospace giant Airbus and depicted some objects as long as 23 metres (75 feet), he said.
The logistical difficulties of the search have been highlighted by the failure so far to get a lock on possible debris despite the now numerous satellite images and direct visuals from aircraft and ships.
The search was called off for a full day earlier this week too because conditions were too dangerous for the search crews, which come from Australia, the United States, New Zealand, China, Japan and South Korea. Meteorologists say the current break in the stormy weather will be short.
Seeking closure in the searing drama, anguished families of those aboard are desperately awaiting hard evidence, which the aviation industry hopes can also provide clues to what caused one of air travel's greatest mysteries.
But as the search continued, US law firm Ribbeck Law Chartered International said it was getting the ball rolling on potentially "multi-million dollar" lawsuits against Malaysia Airlines and Boeing.
MH370 RIP: Malaysian papers turn black in tribute to crashed jet
Malaysia Airlines CEO says must accept reality, offers $5,000 compensation to relatives
Detailed satellite image. Credit: Ministry of Science, Technology and Innovation (Malaysia)
Objects sighted by ARSM. Credit: Ministry of Science, Technology and Innovation (Malaysia)
Airline and Boeing are 'responsible'
"We are going to be filing the lawsuits for millions of dollars per each passenger based on prior cases that we have done involving crashes like this one," the firm's head of aviation litigation, Monica Kelly, told reporters in Kuala Lumpur.
A separate statement by the firm, which filed an initial court petition in the US state of Illinois on Tuesday, said the two companies "are responsible for the disaster of Flight MH370".
The airline declined detailed comment.
The plane deviated inexplicably off its intended course between Kuala Lumpur and Beijing, flying thousands of kilometres in the wrong direction. A search for the plane has been hampered by initial confusion over its flight path, and now poor weather in the remote southern Indian Ocean.
Malaysia's prime minister said Monday that satellite data indicated the plane plunged into the sea in a region around 2,500 kilometres (1,550 miles) off western Australia, possibly after running out of fuel.
Air searches resumed Wednesday after being suspended the previous day due to bad weather, and the Australian naval vessel HMAS Success, as well as ships from China and elsewhere, were also scouring the area.
But still nothing has been pulled from the roiling seas and the weather was expected to worsen Thursday.
Relatives seek closure
MH370 relatives have endured more than a fortnight of agonising uncertainty.
Two-thirds of the passengers were from China, and relatives there have criticised Malaysia in acid terms, accusing the government and airline of a cover-up and botching the response. Scores of relatives protested outside Malaysia's embassy in Beijing on Tuesday.
"I still believe in direct evidence like something from the plane, or something like that. If they got something then maybe I will accept the result," said Steve Wang, whose 57-year-old mother was on board.
The relatives delivered a written protest to the embassy before leaving. (Agencies)
Beijing kept up the pressure, with Premier Li Keqiang urging Malaysia on Wednesday to involve "more Chinese experts" in its investigation, according to a Chinese foreign ministry spokesman.
Malaysia believes the plane was deliberately diverted by someone on board. Scenarios include a hijacking, pilot sabotage or a crisis that incapacitated the crew and left the plane to fly on auto-pilot for hours until it ran out of fuel.
Beijing has demanded that Malaysia share the data, provided by British satellite telecommunications firm Inmarsat, used to conclude the plane crashed somewhere in the Indian Ocean.
Hishammuddin said Prime Minister Najib Razak met Wednesday with Zhang Yesui, a Chinese vice foreign minister sent to Kuala Lumpur over the crisis.
"Malaysia has provided his excellency and his delegation with a full update on the latest information from Inmarsat," Hishammuddin said.
China demands Malaysia share satellite data that confirmed MH370 crash
Photos of some passengers of MH370
'History will judge us well'
Hishammuddin hit back at criticism of Malaysia's handling of the crisis, saying "I think history will judge us well."
Authorities hope to eventually retrieve the "black box" and its precious flight data, believing it could hold clues to what happened.
But Australian Prime Minister Tony Abbott summed up the challenge, calling the crash zone "about as close to nowhere as it's possible to be".
Australian Vice Admiral Ray Griggs said a specialised US Navy black box locator device had arrived in Perth and could be taken to the search area within days.
But experts warned that a chain of undersea volcanoes runs directly through the area, creating a rugged ocean floor that will hamper the search for the black box.
The clock is ticking, with the battery that powers its locator signal expected to run out in two weeks.
(With inputs from Reuters and AFP)