With memories still fresh of the Holy Land's worst storm in 50 years last winter, Israelis and Palestinians stocked up on supplies for a forecast heavy snowfall on Tuesday.

The approaching storm, due to peak on Wednesday, was expected to be lighter than in December 2013, when snow fell for three days, paralysing the region and causing power outages that left tens of thousands cut off from electricity and heat.

Israeli television weatherman Danny Rupp predicted 12 to 24 hours of snowfall in Jerusalem. Barry Lynn, a meteorologist at Hebrew University of Jerusalem, said the storm would likely dump between 25 cm and 60 cm (10 inches and 24 inches) of snow in the city.

Snowploughs and power crews were on alert in Jerusalem, northern Israel and in the Palestinian Territories.

As the skies darkened on Tuesday, Israelis and Palestinians scurried for food supplies and gas or paraffin heaters.

"We ran out quickly," said one salesmen in Jerusalem's Mahane Yehuda market, "There's not a heater to be found anywhere in the area."

Heavy rains and near-freezing temperatures in the approaching storm threatened to deepen the misery in the Gaza Strip, where streets are still strewn with wreckage from a 50-day war with Israel last summer, thousands live in UN shelters and damaged homes and the power is on only six hours a day.

"No electricity, no drinkable water, no reconstruction, and now a storm. Our people need the help of the entire world," said Samir Ali, 47, a Gaza city taxi driver.

Inside a packed supermarket, Jerusalem resident Alon Issashar, 29, said he had hoped to beat the crowds by shopping early.

"As you can see Armageddon is coming," he joked. "People are going crazy. I guess people outside of Israel will laugh but we are used to sun."

In the Palestinian city of Ramallah, shoppers cleaned bread, water and diapers off supermarket shelves.

In Jerusalem, Mayor Nir Barkat said roads to the city were likely to be closed at the sight of the first snowflakes. - Reuters