* Two million Syrian refugees face lethal conditions
* Flights cancelled, oil tankers held up in Turkey
* Heavy snow in Jerusalem and flooding in Gaza
By Stephen Kalin
BEIRUT, Dec 13 (Reuters) - A powerful winter storm sweeping the eastern Mediterranean this week is causing mayhem across the region and inflicting extra misery on Syrians convulsed in civil war and refugees who have fled the fighting.
The storm, named Alexa, is expected to last until Saturday, bringing more snow, rain and freezing temperatures to large swathes of Turkey, Syria, Lebanon, Jordan, Israel and the Palestinian territories.
The bad weather, which began on Wednesday, is taking a disproportionate toll on the 2.2 million refugees living outside Syria and the 6.5 million people displaced within the country.
Biting cold and heavy rain beset Zaatari camp, which houses 80,000 of Jordan's more than half a million Syrian refugees.
Among them was Khalil Atma from Sanameen in southern Syria who was shivering with her two daughters in a flooded, unheated trailer. "We have come from one tragedy to another," she said.
Aid agencies say they are working around the clock to evacuate refugees from flooded camps and distribute food, supplies and clothing, but cannot keep up with demand.
"These people need much more in terms of preparations for winter and organisations are doing their best, but winter conditions are harsh," said Saba Mobaslat, country director of Save the Children International, which operates in Zaatari.
In Lebanon, more than 835,000 Syrians live in tents, unused buildings or with friends or family. UNICEF said needs were outpacing what it and its partners could provide.
In Turkey, authorities distributed extra blankets and winter clothes to many of the 206,000 Syrian refugees at camps along the border, said Mustafa Aydogdu, spokesman for the prime minister's disaster relief agency AFAD.
Refugees sheltering in 16 tent cities and six container camps were also given oil-generated heating lamps to reduce the risk of fire, Aydogdu said. Snow removal and firefighting teams have been established at the camps.
FIGHTING IN THE SNOW
Despite the weather, shelling and clashes raged on this week in Syria, where rebels have been fighting for more than 2-1/2 years to bring down President Bashar al-Assad.
Images on Twitter showed rebels marching through the snow carrying automatic weapons and rocket-propelled grenades.
Photographs from the central Syrian city of Homs revealed blocks of houses devastated by two years of street fighting and air strikes, and now covered in a thick layer of snow.
Al Arabiya television on Friday broadcast an image of a child said to have died from exposure in Syria. Reuters could not independently verify the report.
The World Food Programme said it was distributing 10,000 litres of fuel for cooking and heating to internally displaced families living in 10 shelters in Damascus.
WFP Syria Director Matthew Hollingworth said many Syrians had fled without enough warm clothes or blankets. "Syria is always quite cold in winter but it is quite different when you face a fierce winter in a shelter with very limited resources rather than in the comfort of your own home," he said.
The snow also prevented the start of a United Nations airlift to bring relief supplies from Iraq to tens of thousands of people in Syria's remote northeastern Kurdish areas.
A snowstorm of rare intensity blanketed the Jerusalem area and parts of the occupied West Bank, choking off the city and stranding hundreds in vehicles on impassable roads.
Israeli authorities said at least 50 cm (20 inches) of snow had fallen since Thursday and more was forecast through the day.
"In my 54 years I don't remember a sight like this, such an amount I cannot recall," said Nir Barkat, mayor of Jerusalem.
The Israeli military helped police rescue hundreds of people stranded in vehicles on highways near Jerusalem. More than 500 were given makeshift shelter in a city convention hall.
Highways into the city were shut, with ploughs impeded by falling snow and freezing cold. Broken tree branches toppled electricity wires leaving tens of thousands without power, Israeli media said. Residents were told to stay at home.
Despite the storm, U.S. Secretary of State John Kerry met Prime Minister Benjamin Netanyahu in Jerusalem on Friday to try to spur lagging peace talks. He had met Palestinian President Mahmoud Abbas in the West Bank city of Ramallah the day before.
The storm forced Kerry to cut short his session with Abbas to return to Israel before the roads and border-crossings shut.
In the blinding snow, his convoy's path was cleared only by a Palestinian front-end loader whose driver stuck his head out the door to see all the way from Ramallah to the Israeli border where Israeli police escorted Kerry's party back to the hotel.
The usually 45-minute trip took more than two hours.
An unusual blanket of snow surprised residents in the Gaza Strip who stopped to take pictures of snowy scenes. But the Palestinian territory was also hit by heavy rain that flooded roads and made them impassable. Emergency workers used fishing boats to evacuate 700 people from their homes and provide food, blankets and torches to hundreds of others caught in high water.
Gaza's Hamas government said all its resources and manpower were available to aid rescue operations, including its armed wing usually charged with fighting Israel.
Ismail Haniyeh, prime minister of the Hamas administration, called for fuel to be allowed to enter Gaza. "Gaza survived two wars (against Israel) and it will walk out of this," he said wearing a heavy coat and the yellow jumper of emergency workers as he toured the affected areas overnight.
Fuel shortages in recent weeks have caused Gaza's sole power plant to shut its generators, leaving residents with 12-hour blackouts and disrupting hospitals, sewage treatment facilities and private businesses.
Two days of snowfall in Turkey forced the cancellation of 240 international and domestic flights on Thursday at airports across the country with delays spanning several hours, flag carrier Turkish Airlines said on its website.
The Bosphorus Strait, through which some 10,000 vessels and 150 million tonnes of oil products pass each year, reopened on Thursday after high winds, strong currents and poor visibility prompted maritime officials to bar tankers the previous day.
Five tankers were waiting to enter at both ends of the strait, shipping agent GAC said. (Reporting by Suleiman Al-Khalidi in Amman, Ayla Jean Yackley in Istanbul, Lesley Wroughton in Jerusalem and Nidal Al Mughrabi in Gaza; Writing by Stephen Kalin and Oliver Holmes; Editing by Alistair Lyon)