Local transportation and flood prevention authorities are gearing up for a deluge as local weather forecasters have said two storms may simultaneously bring heavy rain and strong winds to Shanghai as early as Thursday evening.

Shanghai Meteorological Bureau forecasted that both storms are likely to affect the city on Thursday evening and Friday morning.

The typhoon, called Saola, is expected to gain strength overnight and hit the coast of northern Fujian Province and Zhejiang Province Thursday night.

As of 6 pm Tuesday, the typhoon was heading north-northwest at 8 kilometers per hour, said Zhang Ruiyi, a senior official with the weather bureau.

The tropical storm, dubbed Damrey, is expected to affect Shanghai Thursday night before hitting the coast of northern Jiangsu Province and the Shandong Peninsula.

"Both storms may bring heavy rains and strong winds to the city," Zhang told the Global Times. "Shanghai will be cooler Wednesday as both storms approach."

Shanghai Shentong Metro Group, the city's subway operator, said they will have 25 rescue teams on standby from Wednesday to deal with any emergencies on the subway system.

"If wind speeds exceed level 8 or above, trains will run at reduced speeds," the metro operator said in a statement. "If the weather worsens, subway operations may be suspended and affected stations will close."

To get updated information on the subway's operation, residents can visit its website or check its official microblog at Sina Weibo, said Lan Tian, Shentong's press officer.

The company also made preparations to prevent damage from the strong winds at 70 subway construction sites across the city, the subway operator said.

The Shanghai Municipal Flood Control Administration also issued a warning Tuesday as the two storms approached the city, saying that it aims to minimize casualties as heavy rain is forecasted. It urged all ships to return to the docks ahead of the storms.

"Emergency teams are on standby in case of small-scale flooding across the city and they will act accordingly if residents need to be evacuated from inundated areas," said Zhang Zhenyu, deputy director of the administration.