A cold front triggered strong winds and heavy snowfall in northern and northeastern China over the weekend, heralding an early winter this year, meteorologists said on Monday.

They called for contingency plans across a wide range of sectors - from food production to power supply and road safety - to cope with the harsh weather.

In response, local authorities implemented emergency measures, including the temporary suspension of classes and business operations in some parts of the country and an early activation of heating systems.

Fang Chong, chief forecaster at the National Meteorological Center, said that snowfall in northeastern China has started earlier than usual. "The first snow in the region is often seen in late November or early December," he said at a news conference in Beijing.

Fang described the snowfall in the northeastern region as "rather intense", and said it has the potential of reaching a record high in parts of Heilongjiang, the northernmost province and a major food production area. He added that efforts were needed to save crops and protect farm animals in such weather.

The National Meteorological Center said on Sunday that a cold wave had pushed the mercury down in the Xinjiang Uygur and Inner Mongolia autonomous regions and Gansu province. The cold spell is forecast to continue until midweek, bringing a mix of blizzards, sleet and gale-force winds.

Late on Saturday, the center activated its second-lowest level of emergency response for cold waves and blizzards, after issuing a lowest level of emergency response a day earlier.

It issued an orange alert for snowstorms and activated a blue alert for gales. China has a four-tier warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.

The center renewed all three alerts on Monday. It forecast that heavy snowfall and blizzards will hit parts of Inner Mongolia and Heilongjiang, Jilin and Liaoning provinces until early Tuesday. Snowfall could reach 35 millimeters in some of the affected areas, and temperatures could plunge by 10 C to 14 C in parts of Inner Mongolia and northeastern China.

To alleviate the impact of the cold spell, transportation authorities in Inner Mongolia said on Sunday that personnel, equipment and materials are on standby to tackle disruption caused by heavy snowfall. The frequency of road inspections has also been increased to quickly spot damage and avoid traffic disruption.

Yuan Bin, a forecaster at the National Meteorological Center's public meteorological service center, said that snowfall could lead to icy roads and poor visibility, causing traffic disruption.

Up to 20-millimeter-thick layers of ice have been spotted covering some power lines in Jilin and Liaoning.

"This could damage power equipment and disrupt supply at a time of increasing electricity consumption due to heating needs, and authorities need to step up energy storage and make emergency plans," Yuan said.