The so-called "Frankenstorm" is tonight expected to lash the city with winds of up to 90mph and bring surges of up to 11ft, threatening to cause the worst flooding in Lower Manhattan and its outer boroughs in years. The Mayor of New York warned that the "most severe part of the storm is now beginning" and urged people not to go outside until the morning. Michael Bloomberg also warned that while the city would be through the worst of the storm by Tuesday morning, the subway and other public transport would likely remain closed until Wednesday and that other effects of the storm may not be remedied until the weekend. The mayor also revealed that he city had more than 1,000 reports of fallen trees in the city. Even before the wind and rain started on Monday morning, America's most populous city -- home to more than eight million people - had gone into lockdown. At 7pm on Sunday the subway system -- the only sensible way to traverse gridlocked Manhattan -- was closed. Monday across the city, subway platforms that would normally be packed with commuters, were empty. The green lanterns which sit outside every stop, switched off. One local radio station neatly summarised the situation during its "traffic and transit" segment when the host announced: "Transit update: there isn't any." Tunnels linking Manhattan to New Jersey and Brooklyn -- traffic bottlenecks which can often take an hour or more to negotiate -- were at first empty and then,