THE Shanghai Meteorological Bureau issued a blue alert for a cold wave at 5pm yesterday with the temperatures set to fall by 9 to 11 degrees Celsius over the next 48 hours.

The National Meteorological Center in Beijing also issued an orange alert yesterday as a cold wave is expected to sweep across most parts of central and east China.

The strong cold front from the north is hitting Shanghai early this year, meaning the temperatures will be the lowest in December in 20 years,according to TianHongjun, a chief forecaster with the Shanghai weather bureau.

The maximum temperature will decrease from 13 degrees today to freezing point tomorrow, with the low declining from 5 to minus 4.

The lowest temperature will be on the last day of the year, hitting minus 6 degrees in urban areas and minus 8 in suburban districts.

The wind speed will increase from 28 kilometers per hour today to 74 kilometers per hour tomorrow. It will be blowing at 117 kilometers per hour on sea near the city, which may endanger ships.

Moderate rain and sleet are expected today and snowfall in the early hours of Wednesday. The rest of the week will be sunny, the bureau said.

Tiansaid the snow will last for one to two hours due to weak warm and humid air. Although the accumulation of snow is unlikely, people should watch out for icy roads, he said.

To deal with the problems caused by the strong cold front, a drill was held by 10 city departments yesterday.

The drill was based on a unified management system, connecting the transport, disaster response and meteorological systems, and a plug-in unit launched by the Shanghai Meteorological Bureau. It is the first time that a system of this kind was trialed to deal with weather.

Compared with a similar drill at the beginning of the year, the time taken to react to bad weather has been cut. Previously, the alert information was sent to the city’s organizations in five minutes but now it only takes one minute.

The city’s road administrators said that maintenance workers were prepared to deal with the cold weather.

Special attention will be given to ramps at elevated roads, large viaducts of expressways and bridges over the Huangpu River. All maintenance work with water will stop when temperatures are under 5 degrees.

Over 200 professional emergency road maintenance squads have prepared a sufficient amount of straw bags, sand andde-icingsalt as well as vehicles and machines for the purpose.

Shanghai’s greenery authorities have ordered intensified checks on outdoor advertisements and signboards as precautions against gales.

Outdoor advertisements and signboards in crowded areas, which are high above street level, old or lack daily maintenance, are of particular concern, the Shanghai Greenery and Public Sanitation Bureau said. Businesses have been ordered to check their outdoor ads or shop signs to eliminate safety hazards.

Emergency teams to handle the freezing weather and clear snow from the streets have been set up, the bureau said.

Measures to protect trees and plants have been taken and warning signs on icy areas inside parks will be in place.

Shelters across Shanghai will step up efforts to help homeless people get through the winter chill, officials at the Shanghai Civil Affairs Bureau said.

Street patrols will be intensified to provide help to the homeless, seniors, the mentally ill, and those with medical conditions and minors.

The meteorological bureau said the cold wave will leave the city on Friday with temperatures gradually rising to 11 degrees.

ZhaoQiang, vice president and director of cardiac surgery at Ruijin Hospital, said people with high blood pressure should keep warm, and ventilate rooms properly.